JP2018202833A - Droplet discharge head manufacturing method, image forming device manufacturing method, droplet discharge head and image forming device - Google Patents

Abstract

To provide a droplet discharge head manufacturing method, an image forming device manufacturing method, a droplet discharge head and an image forming device which can suppress deterioration in image quality caused by ununiformity of a water repellent film.SOLUTION: The droplet discharge head manufacturing method has: a step of forming water repellent films on a surface at a discharge-side of a nozzle forming substrate and inside a nozzle hole; a step of sticking a protective film to a surface of the water repellent film on the surface at the discharge side of the nozzle forming substrate; a step of removing the water repellent film inside the nozzle hole by plasma processing; and a step of peeling off the protective film. An sticking direction in which the protective film is stuck to the surface is a direction which satisfies angles θ in a range of -10°<θ<10° with respect to a direction in which the droplet discharge head moves relatively to a medium.SELECTED DRAWING: Figure 17

Description

  The present invention relates to a method for manufacturing a droplet discharge head, a method for manufacturing an image forming apparatus, a droplet discharge head, and an image forming apparatus, and in particular, a liquid having a water repellent film around a nozzle hole that is a droplet discharge port. The present invention relates to a droplet discharge head manufacturing technique and an image forming apparatus using the droplet discharge head.

  A droplet discharge head used in an ink jet recording apparatus or the like has a water repellent film formed on the discharge side surface of a nozzle plate in which nozzle holes are arranged. Patent Document 1-2 discloses a method for manufacturing a droplet discharge head including a water-repellent film. The manufacturing method of the droplet ejection head described in Patent Document 1 includes a nozzle forming substrate having nozzle holes, a water repellent film forming step of forming a water repellent film inside the nozzle holes, and a water repellent film surface on the surface of the nozzle forming substrate. A protective film attaching step for attaching the protective film, a plasma irradiation step for removing the water-repellent film inside the nozzle hole by plasma treatment, and a protective film peeling step for peeling the protective film are included.

JP 2013-99880 A JP 2010-143106 A

  The droplet discharge head manufactured by applying the conventional method has a non-uniformity of the water-repellent film in the direction parallel to the direction in which the protective film is applied to the nozzle forming substrate during the protective film application process. Arise. For example, in the protective film application process, the protective film is lifted in the protective film application direction in the vicinity of the nozzle hole, and plasma enters into the lifted part to remove a part of the water-repellent film. The surrounding water-repellent film becomes uneven.

  In addition, a part of the protective film is pushed into the nozzle hole in the protective film attaching process, and the water repellent film inside the nozzle hole is not partially removed by the plasma treatment, and the water repellent film inside the nozzle hole. The remaining water repellent film also causes non-uniformity of the water repellent film.

  If the water-repellent film around the nozzle hole is not uniform, the discharge direction of the liquid droplet discharged from the nozzle hole is bent, and the discharged liquid droplet lands at a position shifted from the target landing position. In the case of an image forming apparatus that forms an image on a medium by attaching droplets ejected from the nozzle holes of the liquid droplet ejection head to the medium, the ejection bending on the medium due to non-uniformity of the water-repellent film The dot formation position is shifted and the quality of the image formed on the medium is deteriorated.

  The present invention has been made in view of such circumstances, and a method of manufacturing a droplet discharge head, a method of manufacturing an image forming apparatus, and a droplet capable of suppressing deterioration in image quality due to non-uniformity of a water repellent film It is an object to provide an ejection head and an image forming apparatus.

  In order to solve the problems, the following aspects of the invention are provided.

  A method of manufacturing a droplet discharge head according to aspect 1 includes a water repellent film forming step of forming a water repellent film on the discharge side surface of a nozzle forming substrate having a plurality of nozzle holes and the inside of the nozzle holes, and discharging of the nozzle forming substrate. Protective film pasting process for attaching a protective film to the surface of the water-repellent film formed on the side surface, plasma irradiation process for removing the water-repellent film inside the nozzle hole by plasma treatment, and peeling the protective film from the nozzle forming substrate A protective film peeling step, and a sticking direction in which the protective film is stuck to the nozzle forming substrate in the protective film sticking step is discharged from a droplet discharge head including the nozzle forming substrate and a nozzle hole. This is a direction satisfying an angle θ in the range of −10 ° <θ <10 ° with respect to the relative movement direction with respect to the medium to which the droplets are deposited.

  According to the aspect 1, even when the water-repellent film around the nozzle hole becomes non-uniform due to variations in how the protective film is applied, the direction in which the defective portion of the non-uniform water-repellent film occurs is The direction is substantially parallel to the relative movement direction of the droplet discharge head and the medium during formation. For this reason, the direction of the discharge bend caused by the non-uniformity of the water-repellent film, that is, the direction in which the landing position (dot formation position) of the discharged droplet deviates is a direction substantially parallel to the relative movement direction and the landing position shift It is difficult to visually recognize image defects. The term “substantially parallel” as used herein refers to parallel or non-parallel including the allowable range of the angle θ in the range of −10 ° <θ <10 °. The allowable range of the angle θ is based on the allowable variation in the attaching direction in the operation of attaching the protective film.

  A method of manufacturing a droplet discharge head according to aspect 2 includes a water repellent film forming step of forming a water repellent film on the discharge side surface of a nozzle forming substrate having a plurality of nozzle holes and the inside of the nozzle holes, and discharging the nozzle forming substrate. Protective film pasting process for attaching a protective film to the surface of the water-repellent film formed on the side surface, plasma irradiation process for removing the water-repellent film inside the nozzle hole by plasma treatment, and peeling the protective film from the nozzle forming substrate A protective film peeling step, and a sticking direction for sticking the protective film to the nozzle forming substrate in the protective film sticking step is a nozzle hole arrangement direction of a nozzle row configured by an arrangement pattern of a plurality of nozzle holes Is a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the direction.

  The nozzle hole arrangement direction when the plurality of nozzle holes are arranged one-dimensionally on the nozzle forming substrate is the arrangement direction of the nozzle holes arranged one-dimensionally.

  When a plurality of nozzle holes are two-dimensionally arranged on the nozzle forming substrate, the nozzle row constituted by the two-dimensional arrangement pattern can be regarded as substantially equivalent to one nozzle row. Means a typical nozzle row. This substantial nozzle row corresponds to a projected nozzle row in which a plurality of two-dimensionally arranged nozzle holes are projected so as to be aligned in the nozzle hole arrangement direction.

  Aspect 3 is a method for manufacturing a liquid droplet ejection head according to aspect 1 or 2, wherein the nozzle hole has a quadrangular shape.

  The square nozzle having a square nozzle hole shape has a greater variation in the peeling of the water-repellent film depending on the application direction to which the protective film is applied, as compared with a nozzle having a circular nozzle hole shape. It is beneficial.

  Aspect 4 includes a step of forming a plurality of nozzle forming substrate dies in the wafer in the method of manufacturing a droplet discharge head according to any one of aspects 1 to 3, and the plurality of dies in the wafer. The water repellent film in the water repellent film forming step is formed in the state of a wafer including a plurality of dies, and the protective film is attached in the protective film affixing step. A manufacturing method of a droplet discharge head performed in a state of a wafer including the same.

  According to the aspect 4, since the water-repellent film is collectively formed on the plurality of nozzle formation substrates while being in the wafer state and the protective film is attached, the manufacturing process is easy.

  A method for manufacturing an image forming apparatus according to aspect 5 includes: a water repellent film forming step of forming a water repellent film on a discharge side surface of a nozzle forming substrate having a plurality of nozzle holes and inside the nozzle holes; and a discharge side of the nozzle forming substrate. A protective film attaching step for attaching a protective film to the surface of the water repellent film formed on the surface, a plasma irradiation step for removing the water repellent film inside the nozzle hole by plasma treatment, and peeling the protective film from the nozzle forming substrate A step of manufacturing a droplet discharge head including a nozzle forming substrate through a protective film peeling step, and a manufactured droplet discharge head and a medium to which a droplet discharged from a nozzle hole of the droplet discharge head is attached. A protective film with respect to the nozzle forming substrate in the protective film pasting step. The affixing direction is a direction satisfying an angle θ in the range of −10 ° <θ <10 ° with respect to the relative movement direction of the medium and the droplet discharge head by the relative movement mechanism. The relative movement mechanism and the droplet discharge head are arranged so as to satisfy the positional relationship in which the angle between the sticking direction and the relative movement direction by the relative movement mechanism is an angle θ in the range of −10 ° <θ <10 °.

  According to the aspect 5, it is possible to obtain an image forming apparatus capable of suppressing the deterioration of the image quality due to the non-uniformity of the water repellent film.

  A method for manufacturing an image forming apparatus according to aspect 6 includes a water repellent film forming step of forming a water repellent film on a discharge side surface of a nozzle forming substrate having a plurality of nozzle holes and the inside of the nozzle holes, and a discharge side of the nozzle forming substrate. A protective film attaching step for attaching a protective film to the surface of the water repellent film formed on the surface, a plasma irradiation step for removing the water repellent film inside the nozzle hole by plasma treatment, and peeling the protective film from the nozzle forming substrate A step of manufacturing a droplet discharge head including a nozzle forming substrate through a protective film peeling step, and a manufactured droplet discharge head and a medium to which a droplet discharged from a nozzle hole of the droplet discharge head is attached. A protective film with respect to the nozzle forming substrate in the protective film pasting step. The affixing direction is a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the nozzle hole arrangement direction of the nozzle row constituted by the arrangement pattern of a plurality of nozzle holes, In the assembling process, the relative movement mechanism and the droplet discharge head are arranged so as to satisfy a positional relationship in which the relative movement direction between the droplet discharge head and the medium by the relative movement mechanism and the nozzle hole arrangement direction are orthogonal to each other.

  According to the aspect 6, it is possible to obtain an image forming apparatus capable of suppressing the deterioration of the image quality due to the non-uniformity of the water repellent film.

  Aspect 7 is a method of manufacturing an image forming apparatus according to Aspect 5 or Aspect 6, wherein the recording of the image on the medium is completed by one relative movement in the relative movement direction between the droplet discharge head and the medium. A method for manufacturing an image forming apparatus.

  Since the single-pass image forming apparatus is easily affected by image deterioration due to ejection bending, the application of the present invention is more useful.

  Aspect 8 is a method for manufacturing an image forming apparatus according to any one of aspects 5 to 7, wherein the image forming apparatus includes an inkjet head bar which is a line head configured using a droplet discharge head. is there.

  Aspect 9 is the image forming apparatus manufacturing method according to aspect 8, wherein the head module as a droplet discharge head is provided with an inkjet head bar configured by connecting a plurality of head modules in the width direction of the medium perpendicular to the relative movement direction. A method of manufacturing an apparatus.

  Aspect 10 is a method for manufacturing an image forming apparatus according to Aspect 8 or Aspect 9, wherein the image forming apparatus includes a plurality of inkjet head bars that eject the same color ink.

  According to the aspect 10, in the variation mode in which the discharge directions of the plurality of nozzle holes are aligned and the discharge is shifted in a specific direction, the image is obtained by combining a plurality of inkjet head bars that discharge the same color ink. Is less noticeable, and it is possible to effectively suppress deterioration in image quality.

  A droplet discharge head according to aspect 11 is a droplet discharge head including a nozzle forming substrate having a plurality of nozzle holes, and a water repellent film formed on the discharge side surface of the nozzle forming substrate. The surrounding water-repellent film is in a direction satisfying an angle θ in the range of −10 ° <θ <10 ° with respect to the relative movement direction between the droplet discharge head and the medium to which the droplet discharged from the nozzle hole is attached. The defective portion of the water repellent film is unevenly distributed.

  By using the droplet discharge head of aspect 11, it is possible to form an image with good image quality in which image defects due to the influence of discharge bending due to the non-uniformity of the water-repellent film are not noticeable.

  A droplet discharge head according to Aspect 12 is a droplet discharge head including a nozzle forming substrate having a plurality of nozzle holes, and a water repellent film formed on the discharge side surface of the nozzle forming substrate. The surrounding water-repellent film is in a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a direction perpendicular to the nozzle hole arrangement direction of the nozzle row constituted by the arrangement pattern of the plurality of nozzle holes. The defective portion of the water repellent film is unevenly distributed.

  By using the droplet discharge head of aspect 12, it is possible to form an image with good image quality in which image defects due to the influence of the discharge bend caused by the non-uniformity of the water repellent film are not noticeable.

  An image forming apparatus according to aspect 13 includes a droplet discharge head including a nozzle forming substrate having a plurality of nozzle holes, a medium and droplets to which droplets discharged from the nozzle holes of the droplet discharge head are attached An image forming apparatus including a relative movement mechanism for moving the ejection head relative to the nozzle head, wherein a water repellent film is formed on the ejection side surface of the nozzle forming substrate, and the water repellent film around the nozzle hole is relatively moved. The defective portion of the water repellent film is unevenly distributed in a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to the relative movement direction of the droplet discharge head and the medium by the mechanism.

  According to the aspect 13, it is possible to form an image with a good image quality in which an image defect due to the influence of the discharge bend caused by the non-uniformity of the water-repellent film is not noticeable.

  The image forming apparatus according to the fourteenth aspect includes a droplet discharge head including a nozzle forming substrate having a plurality of nozzle holes, a medium to which droplets discharged from the nozzle holes of the droplet discharge head are attached, and a droplet An image forming apparatus including a relative movement mechanism that relatively moves the ejection head, wherein a water repellent film is formed on the ejection side surface of the nozzle forming substrate, and the water repellent film around the nozzle hole includes a plurality of water repellent films. Defective portions of the water-repellent film are unevenly distributed in a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the nozzle hole arrangement direction of the nozzle row configured by the nozzle hole arrangement pattern. ing.

  According to the fourteenth aspect, it is possible to form an image with a good image quality in which image defects due to the influence of the discharge bend caused by the non-uniformity of the water-repellent film are not noticeable.

  According to the present invention, it is possible to suppress degradation of image quality due to non-uniformity of the water repellent film.

FIG. 1 is a partial cross-sectional view schematically showing an example of a manufacturing process of a droplet discharge head. FIG. 2 is a partial cross-sectional view schematically showing an example of the manufacturing process of the droplet discharge head. FIG. 3 is a partial cross-sectional view schematically showing an example of the manufacturing process of the droplet discharge head. FIG. 4 is a partial cross-sectional view schematically showing an example of the manufacturing process of the droplet discharge head. FIG. 5 is a partial cross-sectional view schematically showing an example of the manufacturing process of the droplet discharge head. FIG. 6 is a schematic diagram illustrating a state in which droplets are discharged from the nozzle holes of the droplet discharge head. FIG. 7 is a partial cross-sectional view schematically showing the state of the protective film attaching step. FIG. 8 is a partial cross-sectional view schematically showing the plasma irradiation process. FIG. 9 is a partial cross-sectional view schematically showing the state of the protective film peeling step. FIG. 10 is a partial cross-sectional view schematically showing how the droplet discharge head manufactured through the steps shown in FIGS. 7 to 9 is used. FIG. 11 is a partial cross-sectional view schematically showing the state of the protective film sticking step. FIG. 12 is a partial cross-sectional view schematically showing the plasma irradiation process. FIG. 13 is a partial cross-sectional view schematically showing the state of the protective film peeling step. FIG. 14 is a partial cross-sectional view schematically showing how the droplet discharge head manufactured through the steps shown in FIGS. 11 to 12 is used. FIG. 15 is a plan view illustrating a part of the nozzle surface of the droplet discharge head according to the comparative example. FIG. 16 is a diagram schematically illustrating a printing result when a solid image is recorded on a sheet using the droplet discharge head according to the comparative example. FIG. 17 is a plan view illustrating a part of the nozzle surface of the droplet discharge head according to the first embodiment. FIG. 18 is a diagram schematically illustrating a printing result when a solid image is recorded on a sheet using the droplet discharge head according to the first embodiment. FIG. 19 is a plan perspective view showing an example of an arrangement form of the ink jet head bar in the single bar type ink jet recording apparatus. FIG. 20 is a plan perspective view showing an example of an arrangement form of the ink jet head bar in the dual bar type ink jet recording apparatus. FIG. 21 is a diagram illustrating an example of a state of the water-repellent film around the nozzle hole. FIG. 22 is a diagram illustrating an example of the state of the water-repellent film around the nozzle hole. FIG. 23 is a side view schematically showing the discharge bending of the droplet discharge head having the water repellent film state shown in FIG. FIG. 24 is a side view schematically showing the discharge bending of the droplet discharge head having the water repellent film state shown in FIG. FIG. 25 is a diagram illustrating a state of a water-repellent film obtained by applying the technique of the present invention. FIG. 26 is a diagram illustrating a state of a water-repellent film obtained by applying the technique of the present invention. FIG. 27 is a plan view of a plurality of head module dies patterned on a wafer. FIG. 28 is a perspective view of the inkjet head bar. FIG. 29 is an enlarged view of the inkjet head bar as seen from the nozzle surface side. FIG. 30 is a plan view illustrating an example of a nozzle surface of the head module. FIG. 31 is a cross-sectional view showing an example of the internal structure of a droplet discharge element for one nozzle of the head module. FIG. 32 is a side view showing the configuration of the inkjet recording apparatus according to the embodiment. FIG. 33 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Method for manufacturing droplet discharge head>
1 to 5 are partial cross-sectional views schematically showing an example of a manufacturing process of a droplet discharge head. A series of drawings from FIG. 1 to FIG. 5 corresponds to a process chart showing a procedure of a manufacturing method of a droplet discharge head. 1 to 5 show a nozzle forming substrate 10 corresponding to a nozzle plate portion of a droplet discharge head. The droplet discharge head is manufactured through the following procedure 1 to procedure 5.

Procedure 1: Step of Preparing Nozzle Formation Substrate As shown in FIG. 1, first, a nozzle formation substrate 10 is prepared. The nozzle forming substrate 10 is a substrate having nozzle holes 12. The nozzle forming substrate 10 is manufactured using, for example, a silicon substrate. The nozzle hole 12 can be formed by etching. For example, the nozzle hole 12 is processed by anisotropic etching such as reactive ion etching (RIE).

  The nozzle forming substrate 10 may be in a state of a laminated structure in which a flow path forming substrate having another flow path structure (not shown) communicating with the nozzle holes 12 is joined. Further, the nozzle forming substrate 10 may be in a state of a single substrate before another flow path forming substrate or the like is bonded. The nozzle forming substrate 10 is provided with a flow path forming substrate, a piezoelectric element, etc. (not shown) on the upper side of FIG. 1, and droplets are discharged from the nozzle holes 12 toward the lower side of FIG. 1. In FIG. 1, the lower surface of the nozzle forming substrate 10 is a discharge-side surface 10A.

Procedure 2: Water Repellent Film Forming Step Next, as shown in FIG. There are various forms of the material and forming method of the water repellent film 14. The water repellent film 14 can be formed using, for example, a fluorine-based silane coupling agent. The water repellent film 14 can be formed by using, for example, a physical vapor deposition method such as an evaporation method. The water repellent film 14 is formed on the discharge side surface 10 </ b> A and the nozzle inner surface 10 </ b> B of the nozzle forming substrate 10.

Step 3: Protective film sticking step Of the water repellent film 14 formed on the surface of the nozzle forming substrate 10, only the water repellent film 14 attached to the discharge side surface 10A is left, and the water repellent attached to the nozzle inner surface 10B. It is necessary to remove the film 14. Therefore, as shown in FIG. 3, the protective film 16 is affixed to a location where the water repellent film 14 is desired to be left, that is, to the surface of the water repellent film 14 formed on the discharge side surface 10 </ b> A of the nozzle forming substrate 10.

  The protective film 16 is a film adhesive tape in which an adhesive is applied to one side of a film as a substrate. As the protective film 16, for example, a weak adhesive film using a polyester film having a thickness of 80 μm as a base material and using an olefin elastomer as an adhesive can be used. The protective film 16 is attached to the surface of the water-repellent film 14 by bringing the adhesive side of the protective film 16 into contact with the water-repellent film 14. An arrow A in FIG. 3 represents a pasting direction in which the protective film 16 is pasted. The affixing direction means the direction (direction) in which the protective film 16 is affixed. In FIG. 3, the attachment of the protective film 16 proceeds in the direction of the arrow A.

Procedure 4: Plasma Irradiation Step Next, as shown in FIG. 4, the water-repellent film 14 inside the nozzle is removed by plasma processing inside the nozzle. That is, plasma treatment is performed on the nozzle forming substrate 10 from the side opposite to the protective film 16 (from the flow path side connected to the nozzle hole 12), and the water repellent film 14 attached to the nozzle inner surface 10B is removed. As a plasma processing method, for example, after the nozzle forming substrate 10 is placed in a vacuum chamber and then evacuated, oxygen replacement is performed to generate oxygen plasma.

  The plasma can reach the inside of the nozzle via a pressure chamber and other channels formed on a channel forming substrate (not shown). The water repellent film 14 in the plasma exposed area is removed.

  Note that the plasma irradiation step is not limited to the treatment using vacuum-depressurized plasma, and atmospheric pressure plasma by gas flow can also be used. In this case, for example, dry air or nitrogen can be used for the gas flow.

Procedure 5: Protective film peeling process Then, as shown in FIG. 5, the protective film 16 is peeled off from the nozzle forming substrate 10 and removed. Thus, a droplet discharge head including a nozzle plate in which the water repellent film 14 is formed on the discharge side surface 10A of the nozzle forming substrate 10 is obtained.

  FIG. 6 is a cross-sectional view schematically showing a state in use of the droplet discharge head generated through the droplet discharge head manufacturing method including steps 1 to 5. The nozzle 20 is filled with ink 20, and ink droplets 22 are ejected from the nozzle hole 12 by driving a piezoelectric element (not shown).

《Explanation of issues》
In the protective film sticking step described with reference to FIG. 3, the sticking state of the protective film 16 varies, and the protective film 16 may be lifted in the vicinity of the nozzle holes. “Floating” refers to a state in which a portion that should be in close contact is released and a gap is formed between the protective film 16 and the water repellent film 14.

  FIGS. 7 to 10 are explanatory diagrams of the discharge bend caused by the floating of the protective film 16. FIG. 7 is a partial cross-sectional view schematically showing the state of the protective film attaching step. As shown in FIG. 7, the lifting 26 of the protective film 16 may occur in the vicinity of the nozzle hole within the range of variation in the state of application of the protective film 16 permitted in the protective film application process. In the example of FIG. 7, a space due to the lift 26 is generated on the left side of the nozzle hole 12, that is, on the upstream side in the protective film application direction.

  FIG. 8 is a partial cross-sectional view schematically showing the plasma irradiation process. When the plasma irradiation is performed in a state where the protection film 16 has the lift 26, the water repellent film 14 exposed at the lift 26 is removed.

  FIG. 9 is a partial cross-sectional view schematically showing the state of the protective film peeling step. When the protective film 16 is peeled from the nozzle forming substrate 10 after the plasma irradiation step shown in FIG. 8, the nozzle plate in which the water repellent film 14 is formed on the discharge side surface 10A of the nozzle forming substrate 10 as shown in FIG. Is obtained. As is clear from comparison between FIG. 9 and FIG. 4, in the example of FIG. 9, a part of the water repellent film 14 in the vicinity of the nozzle hole 12 is peeled off to form a defective water repellent film portion 30. The water repellent film 14 is uneven.

  FIG. 10 is a partial cross-sectional view schematically showing a state in use of the droplet discharge head generated through the steps described in FIGS. The nozzle 20 is filled with ink 20, and ink droplets 22 are ejected from the nozzle hole 12 by driving a piezoelectric element (not shown). At this time, the ejection direction of the droplets 22 bends toward the water repellent film defective portion 30.

  The group of drawings in FIGS. 11 to 14 is an explanatory diagram of the bending in the ejection direction caused by the rising of the protective film 16 compared with the group of drawings in FIGS. 7 to 10.

  FIG. 11 is a partial cross-sectional view schematically showing the state of the protective film sticking step. As shown in FIG. 11 within the range of variations in the state of application of the protective film 16 allowed in the protective film application process, the lift 26 of the protective film 16 may occur in the vicinity of the nozzle holes. In the example of FIG. 11, a space due to the lift 26 is generated on the right side of the nozzle hole 12, that is, on the downstream side in the protective film application direction.

  FIG. 12 is a partial cross-sectional view schematically showing the plasma irradiation process. When the plasma irradiation is performed in a state where the protection film 16 has the lift 26, the water repellent film 14 exposed at the lift 26 is removed.

  FIG. 13 is a cross-sectional view schematically showing the state of the peeling process. When the protective film 16 is peeled from the nozzle forming substrate 10 after the plasma irradiation step shown in FIG. 12, the nozzle plate having the water repellent film 14 formed on the discharge side surface 10A of the nozzle forming substrate 10 as shown in FIG. Is obtained. As is apparent from a comparison between FIG. 13 and FIG. 4, in the example of FIG. 13, a part of the water repellent film 14 near the nozzle hole 12 is peeled off to produce a defective water repellent film portion 30. The water repellent film 14 is uneven.

  FIG. 14 is a cross-sectional view schematically showing how the droplet discharge head generated through the steps described in FIGS. 11 to 13 is used. The nozzle 20 is filled with ink 20, and ink droplets 22 are ejected from the nozzle hole 12 by driving a piezoelectric element (not shown). The discharge direction of the droplet 22 bends toward the poor water-repellent film portion 30.

  As described with reference to FIGS. 7 to 14, the water-repellent film 14 around the nozzle hole 12 becomes non-uniform due to the floating of the protective film 16 generated in the protective film attaching step, and as a result, the protective film is attached. The discharge direction of the droplet is bent in a direction parallel to the direction. If this is not taken into consideration, the quality of the image formed using the droplet discharge head deteriorates.

  Patent Document 1 and Patent Document 2 do not describe the attaching direction of the protective film. Further, Patent Document 1 and Patent Document 2 do not describe any relation between the relative movement direction of the paper and the droplet discharge head during image formation and the protective film application direction.

  In the present disclosure, even when the non-uniformity (variation) of the water-repellent film due to the method of attaching the protective film 16 occurs, the liquid droplets that can suppress the deterioration of the image quality formed by the liquid droplets discharged from the nozzle holes. A method for manufacturing a discharge head and a method for manufacturing an image forming apparatus are provided. In addition, the present disclosure provides a droplet discharge head and an image forming apparatus that can suppress deterioration in image quality formed by droplets discharged from nozzle holes.

  In this specification, the relative movement direction between the paper and the droplet discharge head during image formation is referred to as “paper-head relative movement direction”. A sheet is an example of a “medium”. In the case of an inkjet recording apparatus that forms an image on a sheet by a single-pass method using a line head, the “paper-head relative movement direction” corresponds to the sheet conveyance direction.

<< Summary of Embodiment 1 >>
In the manufacturing method of the droplet discharge head according to the first embodiment, the direction in which the protective film 16 is applied is the paper-head relative movement direction (θ = 0 °) in the protective film attaching step. As a result, even if the water-repellent film 14 around the nozzle hole 12 becomes non-uniform, the ejection direction curve in the paper-head relative movement direction is not conspicuous as an image quality defect, and thus hardly appears as an image defect.

  This will be specifically described with reference to FIGS. Here, an ink jet recording apparatus that forms an image by a single pass method using a line head is illustrated. In the case of a single-pass inkjet recording apparatus, the “paper-head relative movement direction” corresponds to the paper conveyance direction. The arrangement direction of the nozzle holes 12 in the line head is defined as the X direction, and the paper transport direction is defined as the Y direction. The X direction corresponds to the main scanning direction, and the Y direction corresponds to the sub scanning direction.

<Comparative example>
FIG. 15 is a plan view illustrating a part of the nozzle surface of the droplet discharge head according to the comparative example. FIG. 15 schematically shows the state of the water-repellent film around the nozzle holes. A plurality of nozzle holes 12 are two-dimensionally arranged on the nozzle surface of the droplet discharge head 40. In FIG. 15, for convenience of illustration, only 4 × 3 nozzle holes 12 arranged in 4 rows and 3 columns are shown. The nozzle hole 12 has a quadrangular shape in plan view.

  In FIG. 15, an arrow B indicates a protective film sticking direction in the protective film sticking step. In the droplet discharge head 40, the protective film sticking direction is a direction parallel to the X direction (θ = 90 °), and the defective water repellent film portion 30 is generated at the end of the nozzle in the direction parallel to the X direction. .

  When the droplet discharge head 40 shown in FIG. 15 is mounted on an ink jet recording apparatus and a sheet is conveyed in the Y direction to record an image, the result is as shown in FIG.

  FIG. 16 is a diagram schematically showing a printing result when a solid image is recorded on the paper 44 using the droplet discharge head 40. A solid image refers to an image having a uniform density with a single color. An upward arrow in FIG. 16 indicates the sheet conveyance direction.

  Each of the lines 46 in the Y direction shown in FIG. 16 indicates a line recorded by ejecting ink from each of the 4 × 3 nozzle holes 12 shown in FIG. The ejection direction of each nozzle hole 12 varies in the X direction due to the influence of peeling of the water repellent film 14 (water repellent film defective portion 30). For this reason, the image recorded on the paper 44 has noticeable stripe unevenness.

<Embodiment 1>
On the other hand, FIG. 17 is a plan view showing a part of the nozzle surface of the droplet discharge head according to the first embodiment. FIG. 17 schematically shows the state of the water-repellent film 14 around the nozzle hole 12. A plurality of nozzle holes 12 are two-dimensionally arranged on the nozzle surface of the droplet discharge head 50. In FIG. 17, an arrow C indicates a protective film sticking direction in the protective film sticking step. In the droplet discharge head 50, the protective film sticking direction is a direction parallel to the Y direction, and the poor water repellent film portion 30 occurs at the end of the nozzle in the direction parallel to the Y direction.

  When the droplet discharge head 50 shown in FIG. 17 is mounted on an ink jet recording apparatus and a sheet is conveyed in the Y direction to record an image, the result is as shown in FIG.

  FIG. 18 is a diagram schematically illustrating a printing result when a solid image is recorded on the paper 44 using the droplet discharge head 50. Each line 46 in the Y direction shown in FIG. 18 indicates a line recorded by ejecting ink from each of the 4 × 3 nozzle holes 12 shown in FIG. Although each nozzle hole 12 of the droplet discharge head 50 shown in FIG. 17 is bent in the Y direction due to the peeling off of the water repellent film 14, the X direction corresponds to the X coordinate of each nozzle hole 12. It is discharged accurately. In other words, according to the first embodiment, the influence of the bending in the ejection direction due to the floating of the protective film 16 that is difficult to avoid in the manufacturing process is the direction that coincides with the paper-head relative movement direction. It is hard to appear as a defect in image quality.

  It is easy for the human eye to visually recognize image defects that are connected in the paper conveyance direction. As shown in FIG. 18, the variation in the Y direction (the unevenness of the print start portion and the print completion portion) due to the difference in the position of the print start portion and the print completion portion of each line 46 in the Y direction is visually recognized in the actual printed matter. hard.

  By applying the technique of the present disclosure to a single-pass inkjet recording apparatus in which streak unevenness is likely to occur due to the ejection direction bending in the X direction perpendicular to the paper conveyance direction, a further effect can be obtained.

<Relationship between protective film application direction and paper-head relative movement direction>
The direction in which the protective film is applied is preferably parallel to the paper-head relative movement direction, but is not required to be strictly parallel. In consideration of an allowable range such as a variation in actual protective film application work, the application direction of the protective film is set to an angle θ in a range of −10 ° <θ <10 ° with respect to the paper-head relative movement direction. It is only necessary to satisfy the direction.

  From another viewpoint, the protective film sticking direction is −10 ° <θ <with respect to the direction perpendicular to the nozzle hole arrangement direction of the substantial nozzle row constituted by the arrangement pattern of the two-dimensional nozzle arrangement. Any direction that satisfies the angle θ in the range of 10 ° may be used.

  In the droplet discharge head manufactured by applying the method of manufacturing the droplet discharge head according to the first embodiment, the water-repellent film around the nozzle hole is −10 ° <θ <with respect to the paper-head relative movement direction. The defective portion of the water repellent film is unevenly distributed in the direction satisfying the angle θ in the range of 10 °.

  From another point of view, the droplet discharge head manufactured by applying the droplet discharge head manufacturing method according to Embodiment 1 has a water-repellent film around the nozzle holes arranged in a two-dimensional nozzle array. Defective portions of the water-repellent film are unevenly distributed in a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the nozzle hole arrangement direction of the substantial nozzle row constituted by the pattern. It will be what.

<Nozzle hole shape>
In the first embodiment, a rectangular nozzle hole has been described. Comparing the case where the nozzle hole shape is a square and the case where the nozzle hole shape is a circle, it is more difficult to make the protective film even when the nozzle hole shape is a square. When the protective film is applied to the nozzle forming substrate 10, the circular nozzle has no step, so that it is difficult to lift and can be applied neatly.

  Therefore, when the nozzle hole shape is square, variations in the water-repellent film generated around the nozzle hole are more likely to occur than when the nozzle hole shape is circular. In carrying out the present invention, the shape of the nozzle hole is not particularly limited, but the application of the present invention is more effective particularly for a droplet discharge head having a square nozzle. In addition, the square here refers to a square and a rectangle, and a square nozzle means a square nozzle and a rectangular nozzle.

《About single bar method and dual bar method》
FIG. 19 is a plan perspective view showing an example of an arrangement form of the ink jet head bar in the single bar type ink jet recording apparatus. The single bar method is a device configuration including a single inkjet head bar for each ink color. The ink jet head bar refers to a bar-like ink jet head constituting the line head.

  For example, in the case of an inkjet recording apparatus using four colors of ink of cyan (C), magenta (M), yellow (Y), and black (K), as shown in FIG. 19, one inkjet head bar 70K for each color. , 70C, 70M, 70M, 70Y.

  In the example of FIG. 19, from the upstream side in the paper conveyance direction (from the bottom of FIG. 19) to the downstream side, the black ink discharge amount of the inkjet head bar 70K, the cyan ink discharge ink jet head bar 70C, and the magenta ink discharge amount. The inkjet head bar 70M and the inkjet head bar 70Y for discharging yellow ink are arranged in this order, but the number of ink colors (number of color types) and the arrangement order of the inkjet head bars are not particularly limited.

  FIG. 20 is a plan perspective view showing an example of an arrangement form of the ink jet head bar in the dual bar type ink jet recording apparatus. The dual bar system is an apparatus configuration including two inkjet head bars for each ink color. That is, the dual bar system is a system having two inkjet head bars for discharging the same color ink. For example, in the case of an ink jet recording apparatus using four colors of ink of cyan (C), magenta (M), yellow (Y), and black (K), as shown in FIG. 20, two ink jet head bars 70K1 for each color. , 70K2, 70C1, 70C2, 70M1, 70M2, 70Y1, and 70Y2.

  Also in the case of the dual bar method, the number of ink colors (number of color types) and the arrangement order of the ink jet head bars are not particularly limited.

  In addition to the dual bar system, there may be an apparatus configuration having three or more inkjet head bars for discharging the same color ink. The method having a plurality of inkjet head bars for discharging the same color ink can improve the printing speed as compared with the single bar method.

<< About tendency of peeling of water repellent film (variation mode) >>
There are several types of “variation modes” indicating the tendency of the water-repellent film to peel off. As shown in FIG. 3, in addition to the random peeling mode in which the peeling of the water repellent film 14 around the nozzle hole occurs randomly (irregularly) upstream and / or downstream in the protective film application direction, As shown in FIGS. 21 and 22, the direction in which the water-repellent film 14 is peeled may be determined in one direction.

  21 and 22 are diagrams showing examples of the state of the water-repellent film around the nozzle hole. FIG. 21 shows an example of a case where the water-repellent film tends to be peeled upstream of the protective film application direction around the nozzle hole. FIG. 22 shows an example in the case where the water-repellent film tends to peel off in the downstream side of the protective film application direction around the nozzle hole.

  FIG. 23 is a side view schematically showing the discharge bending of the droplet discharge head 41 having the water repellent film state shown in FIG. As described with reference to FIG. 21, when the water repellent film 14 around the nozzle holes is peeled off in a certain regularity, the direction of the discharge bend of each droplet from each nozzle hole is the same as shown in FIG. The landing positions of the liquid droplets discharged from the nozzle holes are shifted in the same direction.

  FIG. 24 is a side view schematically showing the discharge bending of the droplet discharge head 42 having the water repellent film state shown in FIG. As described with reference to FIG. 22, when the water repellent film 14 around the nozzle holes is peeled in a certain regularity, the direction of the discharge bend of each droplet from the nozzle holes is the same as shown in FIG. 24. At the same time, the landing positions of the droplets discharged from the nozzle holes are shifted in the same direction.

  In the case of a single bar type ink jet recording apparatus using the droplet discharge head 41 or 42 having the water-repellent film state shown in FIG. 21 or FIG. 22, the ink droplets discharged from each nozzle hole are shown in FIG. As shown in FIG. 24, since the entire image is only shifted in the same direction, the printed image is drawn almost finely.

  On the other hand, when the droplet discharge head 41 having the water repellent film state shown in FIG. 21 and the droplet discharge head 42 having the water repellent film state shown in FIG. Since the discharge direction of the ink droplets of the same color is bent in the opposite direction, the shift of the printed image is conspicuous. In the case of the dual bar method, image data is usually divided and sent to two bars, and the two images recorded by each inkjet head bar are shifted in the X direction.

  Therefore, when the dual bar method is applied, even in the variation mode having the water repellent film state shown in FIG. In this respect, by applying the technique of the present invention, it is possible to avoid the occurrence of image defects even in the variation mode of the water repellent film having a certain regularity as described in FIG. 21 or FIG.

  25 and 26 are views showing a state of the water-repellent film obtained by applying the technique of the present invention instead of FIGS. 21 and 22.

  FIG. 25 shows an example in the case where the water-repellent film tends to be peeled upstream of the protective film application direction around the nozzle hole. FIG. 26 shows an example of a case where the water-repellent film tends to be peeled downstream of the protective film application direction around the nozzle hole.

  26 and 26, the water-repellent film is peeled off in the Y direction parallel to the paper transport direction. Therefore, by applying the droplet discharge head having such a water repellent film state to the dual bar method, the two images are displaced in the Y direction, but there is no displacement in the X direction, and the displacement in the Y direction is human. It is hard to be recognized by the eyes.

  Therefore, the present invention is more effective in the dual bar system. In addition to the dual bar method, the application of the present invention is beneficial for a multibar method including two or more inkjet head bars for discharging the same color ink.

<About Wafer Process>
The ink jet head bar is configured by connecting a plurality of head modules in the X direction. The head module is manufactured by processing a silicon substrate. FIG. 27 is a plan view of the dies 62 of the plurality of nozzle forming substrates 10 patterned on the wafer 60, and shows an example of a pattern of the dies 62 constituting the head module.

  The manufacturing method of the droplet discharge head according to the embodiment may include a step of forming the dies 62 of the plurality of nozzle forming substrates 10 in the wafer 60.

  The directions of the plurality of dies 62 in the wafer 60 are aligned. The formation of the water repellent film in the water repellent film forming process is performed in a state of the wafer 60 including a plurality of dies 62. Further, the protective film 16 is attached in the state of the wafer 60 including a plurality of dies 62 in the protective film attaching step.

  As shown in FIG. 27, the protective film 16 can be attached to the entire wafer 60 in the same direction by aligning the directions of the plurality of dies 62. This facilitates the manufacturing process.

<Verification method of non-uniformity of water repellent film>
The non-uniformity of the water repellent film 14 formed on the nozzle surface of the droplet discharge head may be difficult to confirm with the naked eye. The distribution of the water repellent film around the nozzle hole can be investigated using the following method.

  [Method 1] Fluorine distribution is examined using a time-of-flight secondary ion mass spectrometer (TOF-SIMS).

  [Method 2] Wet the periphery of the nozzle hole with a liquid having a low surface tension, and observe the presence or absence of a water-repellent film with a microscope.

<< Configuration example of inkjet head bar >>
A configuration example of an inkjet head bar used in the inkjet recording apparatus according to the embodiment will be described.

  FIG. 28 is a perspective view of the inkjet head bar 110. The inkjet head bar 110 is a print head installed in a drawing unit in a single-pass inkjet recording apparatus, and is a full-line line head in which a plurality of head modules 112-i are arranged in the X direction and are elongated. ing. A full line type line head is also called a page wide head.

  The ink-jet head bar 110 is configured by connecting a plurality of (two or more integers n) head modules 112-i (i = 1, 2,... N) in the X direction. Here, an example in which 17 (n = 17) head modules 112-i are arranged is shown. A plurality of head modules 112-i (i = 1, 2,... N) are attached to and integrated with a common frame 116 to constitute a bar-shaped line head (inkjet head bar).

  The frame 116 functions as a frame for fixing the plurality of head modules 112-i. Each head module 112-i is fixed to the frame 116 with the nozzle surface 120 facing the common direction. The structure of each head module 112-i is common.

  Each head module 112-i is manufactured by applying the method for manufacturing a droplet discharge head according to the first embodiment described above.

  A flexible substrate 118 is connected to each head module 112-i. A drive signal, an ejection control signal, and the like are supplied to each head module 112-i via the flexible substrate 118.

  FIG. 29 is an enlarged view of the inkjet head bar 110 viewed from the nozzle surface 120 side. Each head module 112-i is supported by the head module holding member 122 from both sides in the Y direction, and both ends in the X direction are supported by the head protection member 124.

  FIG. 30 is a plan view illustrating an example of the nozzle surface 120 of the head module 112-i. The head module 112-i has an end surface on the long side along the v direction having an inclination of angle γ with respect to the X direction, and a short side on the short side along the w direction having an inclination of angle α with respect to the Y direction. It is a parallelogram planar view shape which has an end surface. The nozzle holes 12 are two-dimensionally arranged on the nozzle surface 120 of the head module 112-i. 30 shows an example in which the nozzle hole 12 has a circular shape, the nozzle hole 12 may have a quadrangular shape. The projected nozzle row LN projected so that the two-dimensionally arranged nozzle holes 12 are arranged in the X direction is equivalent to a nozzle row in which the nozzle holes 12 are arranged at equal intervals at a nozzle density that achieves the recording resolution. It is.

  By connecting a plurality of head modules 112-i in the X direction (see FIG. 29), the inkjet head bar 110 forms a nozzle row that covers the entire print range of the paper.

  The full-line inkjet head bar applied to the single-pass method is not limited to the case where the entire surface of the paper is used as the printing range, but when a part of the paper is a printing area (for example, a margin around the recording medium). In the case of providing a portion, etc., it is only necessary to form a nozzle row in a range necessary for printing.

  The number of nozzles of the head module 112-i, the nozzle density, and the arrangement form of the nozzles are not particularly limited. Each of the head modules 112-i corresponds to an example of a “droplet discharge head”.

《Example of internal structure of head module》
The head module 112-i includes a discharge energy generating element that generates discharge energy necessary for ink discharge corresponding to each nozzle hole 12. The ejection energy generating element may be, for example, a piezoelectric element or a heating element. The head module 112-i ejects ink droplets on demand according to the drive signal and the ejection control signal supplied via the flexible substrate 118.

  FIG. 31 is a cross-sectional view showing an example of the internal structure of a droplet discharge element for one nozzle of the head module 112-i. The head module 112-i includes a nozzle plate 130 in which the nozzle holes 12 that are ink droplet ejection ports are formed, a pressure chamber 132 corresponding to the nozzle holes 12, a supply port 134, and a common channel 136. And a formed flow path forming plate 138. The nozzle plate 130 is a member corresponding to the nozzle forming substrate 10.

  The flow path forming plate 138 constitutes a side wall portion of the pressure chamber 132 and a flow that forms a supply port 134 as a narrowed portion (most narrowed portion) of an individual supply path that guides ink from the common flow path 136 to the pressure chamber 132. It is a path forming member. The flow path forming plate 138 may be composed of a single substrate, or may have a structure in which a plurality of substrates are stacked. The nozzle plate 130 and the flow path forming plate 138 can be processed into a required shape using a semiconductor manufacturing technique using silicon as a material.

  A plurality of pressure chambers 132 are connected to the common flow path 136 via respective supply ports 134. Ink is supplied to the common flow path 136 from the outside of the head module 112-i.

  The diaphragm 140 that constitutes a part of the pressure chamber 132 (the top surface in FIG. 31) is provided with a piezoelectric element 144 having an individual electrode 142 for each pressure chamber 132. The diaphragm 140 of this example is made of silicon with a conductive layer functioning as a common electrode 146 corresponding to the lower electrode of the piezoelectric element 144, and also serves as a common electrode of the piezoelectric element 144 disposed corresponding to each pressure chamber 132. . It is also possible to form the diaphragm with a non-conductive material such as resin. In this case, a common electrode layer made of a conductive material such as metal is formed on the surface of the diaphragm member. Moreover, you may comprise the diaphragm which serves as a common electrode with metals (electroconductive material), such as stainless steel.

  By applying a driving voltage to the individual electrode 142, the piezoelectric element 144 is deformed to change the volume of the pressure chamber 132, and ink is ejected from the nozzle hole 12 due to the pressure change accompanying this. After ink ejection, new ink is refilled into the pressure chamber 132 from the common flow path 136 through the supply port 134.

  The head module 112-i selects a driving voltage to be applied to the individual electrode 142, so that a small droplet with a relatively small amount of ink from each nozzle hole 12, a medium droplet with a relatively large amount of ink than a small droplet, In addition, any one of the three types of ink droplets, that is, a large droplet having a relatively larger amount of ink than the middle droplet, can be ejected.

  The ink chamber unit 150 including the nozzle hole 12, the pressure chamber 132, the supply port 134, and the piezoelectric element 144 is a droplet discharge element as a recording element unit for recording one pixel. The head module 112-i includes a plurality of ink chamber units 150 corresponding to the two-dimensional nozzle array described with reference to FIG. The nozzle portion including the nozzle hole 12 may be referred to as “nozzle”. The ink chamber unit 150 is an example of an ejector as a droplet discharge mechanism.

<< Device configuration example of inkjet recording apparatus >>
FIG. 32 is a side view showing the configuration of the inkjet recording apparatus 201 according to the embodiment. The ink jet recording apparatus 201 is an example of an image forming apparatus. The ink jet recording apparatus 201 includes a paper feeding unit 210, a processing liquid applying unit 220, a processing liquid drying unit 230, a drawing unit 240, an ink drying unit 250, and a stacking unit 260.

  The paper feeding unit 210 automatically feeds the paper P one by one. The paper feeding unit 210 includes a paper feeding device 212, a feeder board 214, and a paper feeding drum 216. The type of the paper P is not particularly limited. For example, printing paper mainly composed of cellulose, such as high-quality paper, coated paper, and art paper, can be used. The paper P corresponds to one form of a medium on which an image is formed. The paper P is placed on the paper feed table 212A in a bundled state in which a large number of sheets are stacked.

  The sheet feeding device 212 takes out the bundled sheets P set on the sheet feeding table 212A one by one in order from the top, and feeds them to the feeder board 214. The feeder board 214 conveys the paper P received from the paper feeding device 212 to the paper feeding drum 216.

  The paper supply drum 216 receives the paper P fed from the feeder board 214 and conveys the received paper P to the processing liquid application unit 220.

  The processing liquid application unit 220 applies the processing liquid to the paper P. The treatment liquid is a liquid having a function of aggregating, insolubilizing or increasing the viscosity of the color material component in the ink. The treatment liquid application unit 220 includes a treatment liquid application drum 222 and a treatment liquid application device 224.

  The treatment liquid application drum 222 receives the paper P from the paper supply drum 216 and transfers the received paper P to the treatment liquid drying unit 230. The treatment liquid coating drum 222 includes a gripper 223 on the peripheral surface, and the gripper 223 grips and rotates the leading end portion of the paper P, so that the paper P is wound around the peripheral surface and conveyed.

  The processing liquid coating device 224 applies the processing liquid to the paper P conveyed by the processing liquid coating drum 222. The treatment liquid is applied with a roller.

  The processing liquid drying unit 230 performs a drying process on the paper P coated with the processing liquid. The processing liquid drying unit 230 includes a processing liquid drying drum 232 and a hot air blower 234. The processing liquid drying drum 232 receives the paper P from the processing liquid coating drum 222 and transfers the received paper P to the drawing unit 240. The treatment liquid drying drum 232 includes a gripper 233 on the peripheral surface. The treatment liquid drying drum 232 conveys the paper P by gripping and rotating the leading end of the paper P with the gripper 233.

  The hot air blower 234 is installed inside the processing liquid drying drum 232. The hot air blower 234 blows hot air onto the paper P conveyed by the processing liquid drying drum 232 to dry the processing liquid.

  The drawing unit 240 includes a drawing drum 242, a head unit 244, and an image reading device 248. The drawing drum 242 receives the paper P from the treatment liquid drying drum 232 and transfers the received paper P to the ink drying unit 250. The drawing drum 242 includes a gripper 243 on the circumferential surface, and grips and rotates the leading edge of the paper P with the gripper 243, whereby the paper P is wound around the circumferential surface and conveyed. The drawing drum 242 includes a suction mechanism (not shown), and transports the paper P wound around the peripheral surface while attracting the peripheral surface to the peripheral surface. A negative pressure is used for the adsorption. The drawing drum 242 has a large number of suction holes on the peripheral surface, and sucks the paper P onto the peripheral surface by suction from the inside through the suction holes.

  The head unit 244 includes inkjet heads 246C, 246M, 246Y, and 246K. The inkjet head 246C is a recording head that discharges cyan (C) ink droplets. The ink-jet head 246M is a recording head that ejects magenta (M) ink droplets. The inkjet head 246Y is a recording head that discharges yellow (Y) ink droplets. The ink jet head 246K is a recording head that ejects black (K) ink droplets. Ink is supplied to each of the inkjet heads 246C, 246M, 246Y, and 246K from an ink tank (not shown) that is an ink supply source of a corresponding color via a pipe path (not shown).

  Each of the inkjet heads 246C, 246M, 246Y, and 246K is the inkjet head bar 110 described with reference to FIGS.

  Each of the inkjet heads 246 </ b> C, 246 </ b> M, 246 </ b> Y, and 246 </ b> K is configured by a line head corresponding to the paper width, and each nozzle surface is disposed to face the peripheral surface of the drawing drum 242. The paper width here refers to the paper width in a direction orthogonal to the conveyance direction of the paper P. The inkjet heads 246C, 246M, 246Y, and 246K are arranged at a constant interval along the conveyance path of the paper P by the drawing drum 242.

  Although not shown in the drawing, a plurality of nozzle holes, which are ink ejection ports, are two-dimensionally arranged on the nozzle surfaces of the inkjet heads 246C, 246M, 246Y, and 246K. “Nozzle surface” refers to an ejection surface on which nozzles are formed, and is synonymous with terms such as “ink ejection surface” or “nozzle formation surface”. A nozzle arrangement of a plurality of nozzles arranged two-dimensionally is called a “two-dimensional nozzle arrangement”.

  Each of the inkjet heads 246C, 246M, 246Y, and 246K can be configured by connecting a plurality of head modules in the paper width direction. Each of the inkjet heads 246C, 246M, 246Y, and 246K can complete image recording with a specified recording resolution in one scan of the entire recording area of the paper P in the paper width direction orthogonal to the transport direction of the paper P. This is a full-line type recording head having various nozzle rows. The specified recording resolution may be a recording resolution predetermined by the inkjet recording apparatus 201, or may be a recording resolution set by user selection or by automatic selection by a program corresponding to the print mode. Also good. The recording resolution can be set to 1200 dpi, for example. The paper width direction perpendicular to the paper P transport direction may be referred to as the nozzle row direction of the line head, and the paper P transport direction may be referred to as the nozzle row vertical direction.

  In the case of an inkjet head having a two-dimensional nozzle array, the projection nozzle array in which the nozzles in the two-dimensional nozzle array are projected (orthographically projected) along the nozzle array direction achieves the maximum recording resolution in the nozzle array direction. It can be considered that the nozzle density is equivalent to a single nozzle row in which each nozzle is arranged at approximately equal intervals. The “substantially equidistant” means that the droplet ejection points that can be recorded by the ink jet recording apparatus are substantially equidistant. For example, the concept of “equally spaced” also includes cases where the intervals are slightly different in consideration of manufacturing errors and movement of droplets on the medium due to landing interference. In consideration of the projection nozzle row (also referred to as “substantial nozzle row”), a nozzle number representing a nozzle position can be associated with each nozzle in the arrangement order of the projection nozzles arranged along the nozzle row direction.

  The nozzle arrangement form in each of the inkjet heads 246C, 246M, 246Y, and 246K is not limited, and various nozzle arrangement forms can be adopted. For example, instead of a matrix-like two-dimensional array, a linear array of lines, a V-shaped nozzle array, a polygonal nozzle array such as a W-shape with a V-shaped array as a repeating unit, and the like are also possible. It is.

  Ink droplets are ejected from the inkjet heads 246C, 246M, 246Y, and 246K toward the paper P conveyed by the drawing drum 242, and the ejected liquid droplets adhere to the paper P, whereby an image is formed on the paper P. To be recorded.

  The drawing drum 242 functions as a means for relatively moving the inkjet heads 246C, 246M, 246Y, 246K and the paper P. The drawing drum 242 corresponds to one form of a relative movement mechanism that moves the paper P relative to the inkjet heads 246C, 246M, 246Y, and 246K. The ejection timings of the ink jet heads 246C, 246M, 246Y, and 246K are synchronized with a rotary encoder signal obtained from a rotary encoder installed on the drawing drum 242. In FIG. 32, the rotary encoder is not shown. The ejection timing is the timing at which ink droplets are ejected, and is synonymous with the droplet ejection timing.

  In this example, the configuration of CMYK standard colors (four colors) is illustrated. However, the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. Etc. may be added. For example, it is possible to add an inkjet head that ejects light-colored inks such as light cyan and light magenta, and an inkjet head that ejects special color inks such as green and orange. The arrangement order of the heads is not particularly limited.

  The inkjet heads 246C, 246M, 246Y, and 246K are examples of image forming units.

  The image reading device 248 is an optical reading device that optically reads an image recorded on the paper P by the inkjet heads 246C, 246M, 246Y, and 246K and generates electronic image data indicating the read image. The image reading device 248 includes an imaging device that captures an image recorded on the paper P and converts it into an electrical signal indicating image information. In addition to the imaging device, the image reading device 248 may include an illumination optical system that illuminates a reading target and a signal processing circuit that processes a signal obtained from the imaging device and generates digital image data.

  The image reading device 248 is constituted by, for example, a line scanner using a CCD (Charge Coupled Device) line sensor. The image reading device 248 is preferably configured to read a color image. In the image reading apparatus 248 of this example, a color CCD linear image sensor is used as an imaging device, for example. The color CCD linear image sensor is an image sensor in which light receiving elements having color filters of R (red), G (green), and B (blue) colors are arranged linearly. A color CMOS (complementary metal oxide semiconductor) linear image sensor may be used instead of the color CCD linear image sensor. The image reading device 248 reads an image on the paper P while the paper P is being conveyed by the drawing drum 242.

  Based on the read image data read by the image reading device 248, information such as image density and ejection failure of the inkjet heads 246C, 246M, 246Y, and 246K is obtained.

  The ink drying unit 250 performs a drying process on the paper P on which the image is recorded by the drawing unit 240. The ink drying unit 250 includes a chain delivery 310, a paper guide 320, and a hot air blowing unit 330.

  The chain delivery 310 receives the paper P from the drawing drum 242 and transfers the received paper P to the stacking unit 260. The chain delivery 310 includes a pair of endless chains 312 that travel along a prescribed travel route, and grips the leading end of the paper P with a gripper 314 provided on the pair of chains 312 to convey the paper P in a prescribed manner. Transport along the route. A plurality of grippers 314 are provided in the chain 312 at regular intervals.

  The paper guide 320 is a member that guides the conveyance of the paper P by the chain delivery 310. The paper guide 320 includes a first paper guide 322 and a second paper guide 324. The first paper guide 322 guides the paper P that is transported in the first transport section of the chain delivery 310. The second sheet guide 324 guides the sheet conveyed in the second conveyance section subsequent to the first conveyance section. The hot air blowing unit 330 blows hot air on the paper P conveyed by the chain delivery 310.

  The stacking unit 260 includes a stacking device 262 that receives and stacks the paper P conveyed from the ink drying unit 250 by the chain delivery 310.

  The chain delivery 310 releases the paper P at a predetermined stacking position. The stacking device 262 includes a stacking tray 262A, receives the paper P released from the chain delivery 310, and stacks the sheets P on the stacking tray 262A. The stacking unit 260 corresponds to a paper discharge unit.

<Description of control system of inkjet recording apparatus>
FIG. 33 is a block diagram illustrating a schematic configuration of a control system of the inkjet recording apparatus 201. The ink jet recording apparatus 201 includes a system controller 300. The system controller 300 includes a CPU 300A, a ROM 300B, and a RAM 300C. CPU is an abbreviation for Central Processing Unit. ROM is an abbreviation for Read Only Memory. RAM is an abbreviation for Random Access Memory. Note that storage units such as the ROM 300B and the RAM 300C may be provided outside the system controller 300.

  The system controller 300 functions as an overall control unit that comprehensively controls each unit of the inkjet recording apparatus 201. The system controller 300 functions as a calculation unit that performs various calculation processes. Further, the system controller 300 functions as a memory controller that controls reading and writing of data in memories such as the ROM 300B and the RAM 300C.

  The ink jet recording apparatus 201 includes a communication unit 302, an image memory 304, a conveyance control unit 350, a paper feed control unit 352, a processing liquid application control unit 354, a processing liquid drying control unit 356, a drawing control unit 358, an ink drying control unit 360, And a paper discharge control unit 364. These elements of each part can be realized by one or a plurality of computers. That is, each element of the control system including the system controller 300 can be configured by a combination of computer hardware and software.

  The communication unit 302 includes a communication interface (not shown), and can exchange data with the host computer 400 connected to the communication interface.

  The image memory 304 functions as a temporary storage unit for various data including image data. Image data captured from the host computer 400 via the communication unit 302 is temporarily stored in the image memory 304.

  The conveyance control unit 350 controls the operation of the conveyance system 211 for the paper P in the inkjet recording apparatus 201. The transport system 211 includes paper transport mechanisms such as the paper supply drum 216, the processing liquid coating drum 222, the processing liquid drying drum 232, and the drawing drum 242 shown in FIG. Further, the transport system 211 includes a drive unit such as a motor and a motor drive circuit (not shown) as a power source.

  The paper feed control unit 352 shown in FIG. 22 operates the paper feed unit 210 in response to a command from the system controller 300. The paper feed control unit 352 controls the paper P supply start operation, the paper P supply stop operation, and the like.

  The processing liquid application control unit 354 operates the processing liquid application unit 220 in response to a command from the system controller 300. The processing liquid application control unit 354 controls the application amount of the processing liquid, the application timing, and the like.

  The processing liquid drying control unit 356 operates the processing liquid drying unit 230 in response to a command from the system controller 300. The treatment liquid drying control unit 356 controls the drying temperature, the flow rate of the drying gas, the drying gas injection timing, and the like.

  The drawing control unit 358 controls the operation of the drawing unit 240 in response to a command from the system controller 300. The drawing control unit 358 includes an image processing unit, a waveform generation unit, a waveform storage unit, and a drive circuit. The illustration of the image processing unit, waveform generation unit, waveform storage unit, and drive circuit is omitted. The image processing unit forms dot data from the input image data. The waveform generator generates a drive voltage waveform. The waveform storage unit stores the waveform of the drive voltage. The drive circuit generates a drive voltage having a drive waveform corresponding to the dot data. The drive circuit supplies a drive voltage to the liquid discharge head.

  In the image processing unit, color separation processing for separating input image data into RGB colors, color conversion processing for converting RGB into CMYK, correction processing such as gamma correction and unevenness correction, and gradation values for each color pixel. A halftone process for converting to a gradation value less than the original gradation value is performed.

  As an example of the input image data, raster data represented by digital values from 0 to 255 can be cited. The dot data obtained as a result of the halftone process may be binary, or may be a multi-value that is three or more and less than the gradation value before the halftone process.

  Based on the dot data generated through the processing by the image processing unit, the ejection timing and ink ejection amount at each pixel position are determined, the ejection timing at each pixel position, the drive voltage corresponding to the ink ejection amount, and the ejection of each pixel. A control signal for determining the timing is generated, this drive voltage is supplied to the liquid discharge head, and dots are recorded by the ink discharged from the liquid discharge head.

  The drawing control unit 358 may include a correction processing unit (not shown). The correction processing unit executes a correction process for the abnormal nozzle. When the correction process is performed, a decrease in image quality due to the occurrence of abnormal nozzles is suppressed.

  The ink drying control unit 360 operates the ink drying unit 250 in response to a command from the system controller 300. The ink drying control unit 360 controls the drying gas temperature, the flow rate of the drying gas, or the ejection timing of the drying gas.

  The paper discharge control unit 364 operates the stacking unit 260 in response to a command from the system controller 300. When the stacking device 262 shown in FIG. 32 includes an elevating mechanism, the paper discharge control unit 324 controls the operation of the elevating mechanism according to the increase or decrease of the paper P.

  The ink jet recording apparatus 201 illustrated in FIG. 33 includes an operation unit 331, a display unit 332, a parameter storage unit 334, and a program storage unit 336.

  The operation unit 331 includes an input device including operation buttons, a keyboard, a mouse, a touch panel, or a combination thereof. The operation unit 331 may include a plurality of types of operation members. The illustration of the operation member is omitted.

  Information input via the operation unit 331 is sent to the system controller 300. The system controller 300 executes various processes according to information sent from the operation unit 331.

  The display unit 332 includes a display device (display) such as a liquid crystal panel. The display unit 332 can display various pieces of information such as various setting information of the apparatus or abnormality information in response to a command from the system controller 300. The operation unit 331 and the display unit 332 constitute a user interface. The user can set various parameters and input and edit various information using the operation unit 331 while viewing the content displayed on the screen of the display unit 332.

  The parameter storage unit 334 stores various parameters used for the inkjet recording apparatus 201. Various parameters stored in the parameter storage unit 334 are read out via the system controller 300 and set in each unit of the apparatus.

  The program storage unit 336 stores a program used for each unit of the inkjet recording apparatus 201. Various programs stored in the program storage unit 336 are read out via the system controller 300 and executed in each unit of the apparatus.

  The ink jet recording apparatus 201 shown in FIG. 33 includes a maintenance control unit 338. The maintenance control unit 338 controls the operation of the maintenance unit 340 in accordance with a command from the system controller 300. The operation of the maintenance unit 340 includes an operation of applying a cleaning liquid to a web (not shown) and a wiping operation by the web. Further, the operation in the maintenance unit 340 may include a purge process of the inkjet head, preliminary ejection, and the like.

  33, the system controller 300, the conveyance control unit 350, the paper feed control unit 352, the processing liquid application control unit 354, the processing liquid drying control unit 356, the drawing control unit 358, the ink drying control unit 360, and the paper discharge control unit 364. The hardware structure of a processing unit that executes various types of processing such as the maintenance control unit 338 is the following various types of processors.

  Various processors are processors whose circuit configuration can be changed after manufacturing, such as a CPU (Central Processing Unit) and a FPGA (Field Programmable Gate Array), which are general-purpose processors that execute programs and function as various processing units. Examples include a dedicated electric circuit that is a processor having a circuit configuration specifically designed to execute a specific process such as a programmable logic device (PLD) or an application specific integrated circuit (ASIC). A program is synonymous with software.

  One processing unit may be configured by one of these various processors, or may be configured by two or more processors of the same type or different types. For example, one processing unit may be configured by a plurality of FPGAs or a combination of a CPU and an FPGA. Further, the plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units with one processor, first, as represented by a computer such as a client or server, one processor is configured with a combination of one or more CPUs and software. There is a form in which the processor functions as a plurality of processing units. Secondly, as represented by System On Chip (SoC), etc., there is a form of using a processor that realizes the functions of the entire system including a plurality of processing units with one IC (Integrated Circuit) chip. is there. As described above, various processing units are configured using one or more of the various processors as a hardware structure.

  Further, the hardware structure of these various processors is more specifically an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

<< About the manufacturing method of the inkjet recording device 201 >>
The inkjet recording apparatus 201 can be manufactured by combining inkjet heads 246C, 246M, 246Y, and 246K manufactured by applying the manufacturing method of the droplet discharge head according to Embodiment 1 and various elements such as the drawing drum 242. .

  The process of assembling the ink jet heads 246C, 246M, 246Y, and 246K with the drawing drum 242 being aligned corresponds to an example of the assembling process.

  In the assembly process for manufacturing the inkjet recording apparatus 201, the angle relationship between the direction in which the protective film is applied and the sheet conveyance direction by the drawing drum 242 satisfies the positional relationship in which the angle θ is in the range of −10 ° <θ <10 °. As described above, the drawing drum 242 and the inkjet heads 246C, 246M, 246Y, and 246K are arranged.

  For example, in the assembly process for assembling the inkjet recording apparatus 201 of the embodiment, the positional relationship in which the paper conveyance direction by the drawing drum 242 and the substantial nozzle hole arrangement direction of each inkjet head 246C, 246M, 246Y, 246K are orthogonal to each other. The drawing drum 242 and the inkjet heads 246C, 246M, 246Y, and 246K are arranged so as to satisfy the condition. The method for manufacturing the ink jet recording apparatus 201 corresponds to an example of “a method for manufacturing an image forming apparatus”.

<< Advantages of the Embodiment >>
According to the above-described embodiment, even if the water-repellent film varies around the nozzle hole, the defective portion of the water-repellent film is unevenly distributed in a direction substantially parallel to the paper-head relative movement direction, and the discharge bends. It is difficult to visually recognize image defects. According to this embodiment, image defects such as streak unevenness due to the non-uniformity of the water-repellent film are not noticeable, and image formation with good quality is possible.

<< Discharge method of droplet discharge head >>
The ejector of the droplet discharge head includes a nozzle that discharges liquid, a pressure chamber that communicates with the nozzle, and a discharge energy generation element that applies discharge energy to the liquid in the pressure chamber. With respect to the ejection method for ejecting liquid droplets from the nozzle of the ejector, the means for generating the ejection energy is not limited to the piezoelectric element, and various ejection energy generating elements such as a heating element and an electrostatic actuator can be applied. For example, it is possible to employ a method in which droplets are ejected using the pressure of film boiling caused by heating of a liquid by a heating element. Corresponding ejection energy generating elements are provided in the flow path structure according to the ejection method of the inkjet head.

<< Modification 1 >>
In the above-described embodiment, the single-pass inkjet recording apparatus has been described as an example of the image forming apparatus. However, the present invention can be applied to various forms of image forming apparatuses using a droplet discharge head.

<< Modification 2 >>
In the above-described embodiment, an inkjet head bar in which a plurality of head modules are combined is illustrated, but an image forming apparatus using a single droplet discharge head may be used.

<< Modification 3 >>
In FIG. 32, a single bar type ink jet recording apparatus is illustrated, but an ink jet recording apparatus including a plurality of ink jet head bars that discharge the same color ink, such as a dual bar type, may be used.

<< Modification 4 >>
In the above description, the non-uniformity of the water-repellent film due to the peeling of the water-repellent film has been described. However, the non-uniformity of the water-repellent film due to a part of the water-repellent film remaining inside the nozzle hole is also protected. This is the same as in the case of peeling in that defective portions of the water-repellent film are unevenly distributed in a direction parallel to the direction in which the film is applied.

<About paper>
“Paper” is a medium used for image formation. The term “paper” is a generic term for a variety of terms such as recording paper, printing paper, printing medium, printing medium, printing medium, image forming medium, image forming medium, image receiving medium, and discharged medium. The material, shape, and the like of the paper are not particularly limited, and various sheet bodies can be used regardless of sealing paper, resin sheet, film, cloth, nonwoven fabric, and other materials and shapes. The paper recording is not limited to a sheet medium, but may be a continuous medium such as continuous paper. Further, the sheet of paper is not limited to a cut sheet that has been preliminarily adjusted to a predetermined size, and may be obtained by cutting from a continuous medium to a predetermined size as needed.

《Terminology》
The term “image forming apparatus” is synonymous with terms such as a printing press, a printer, a printing apparatus, a printing apparatus, an image recording apparatus, an image output apparatus, or a drawing apparatus.

  “Image” is to be interpreted in a broad sense, and includes a color image, a monochrome image, a single color image, a gradation image, a uniform density (solid) image, and the like. The “image” is not limited to a photographic image, but is used as a comprehensive term including a pattern, a character, a symbol, a line drawing, a mosaic pattern, a color painting pattern, other various patterns, or an appropriate combination thereof.

  “Formation” of an image includes the concept of terms such as image recording, printing, printing, drawing, and printing. “Printing” includes the concept of digital printing based on digital data.

  In addition, the “image” is not limited to an image formed with ink containing a color material, and other functions such as a treatment liquid applied to the paper before ink application and / or a varnish applied to the paper after ink application. It may be an image formed of a sexual material.

  In the present specification, the term “orthogonal” or “perpendicular” refers to a case of intersecting at an angle of substantially 90 ° in an aspect of intersecting at an angle of less than 90 ° or greater than 90 °. The mode which produces the same operation effect as is included.

  The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Nozzle formation board | substrate 10A Discharge side surface 10B Nozzle inner surface 12 Nozzle hole 14 Water repellent film 16 Protective film 20 Ink 22 Droplet 30 Water repellent film defective part 40, 41, 42 Droplet discharge head 44 Paper 46 Line 50 Droplet discharge Head 60 Wafer 62 Die 70K, 70C, 70M, 70Y Inkjet head bar 70C1, 70C2, Inkjet head bar 70K1, 70K2 Inkjet head bar 70M1, 70M2 Inkjet head bar 70Y1, 70Y2 Inkjet head bar 110 Inkjet head bar 112-i Head module 116 Frame 118 Flexible substrate 120 Nozzle surface 122 Head module holding member 124 Head protection member 130 Nozzle plate 132 Pressure chamber 134 Supply port 136 Common flow path 1 8 Flow Forming Plate 140 Vibration Plate 142 Individual Electrode 144 Piezoelectric Element 146 Common Electrode 150 Ink Chamber Unit 201 Inkjet Recording Device 210 Paper Feed Unit 211 Transport System 212 Paper Feed Device 212A Paper Feed Stand 214 Feeder Board 216 Paper Feed Drum 220 Processing Solution Application unit 222 Treatment liquid application drum 223 Gripper 224 Treatment liquid application device 230 Treatment liquid drying unit 232 Treatment liquid drying drum 233 Gripper 234 Hot air blower 240 Drawing unit 242 Drawing drum 243 Gripper 244 Head unit 246K Inkjet head 246C Inkjet head 246M Inkjet head 246Y Inkjet head 248 Image reading device 250 Ink drying unit 260 Stacking unit 262 Stacking device 262A Stacking tray 300 System controller 302 Communication unit 04 Image memory 310 Chain delivery 312 Chain 314 Gripper 316 Processing liquid drying control unit 320 Paper guide 322 First paper guide 324 Second paper guide 330 Hot air blowing unit 331 Operation unit 332 Display unit 334 Parameter storage unit 336 Program storage unit 338 Maintenance Control unit 340 Maintenance unit 350 Transport control unit 352 Paper feed control unit 354 Processing liquid application control unit 356 Processing liquid drying control unit 358 Drawing control unit 360 Ink drying control unit 364 Paper discharge control unit 400 Host computer LN Projecting nozzle array P Paper

Claims (14)

A water repellent film forming step of forming a water repellent film on the discharge side surface of the nozzle forming substrate having a plurality of nozzle holes and inside the nozzle holes;
A protective film attaching step of attaching a protective film to the surface of the water repellent film formed on the discharge side surface of the nozzle forming substrate;
A plasma irradiation step of removing the water-repellent film inside the nozzle hole by plasma treatment;
A protective film peeling step for peeling the protective film from the nozzle forming substrate,
In the protective film attaching step, the protective film is attached to the nozzle forming substrate in the attaching direction by attaching a droplet discharge head including the nozzle forming substrate and a droplet discharged from the nozzle hole. A method for manufacturing a droplet discharge head, which is a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a relative movement direction with respect to a medium to be made. A water repellent film forming step of forming a water repellent film on the discharge side surface of the nozzle forming substrate having a plurality of nozzle holes and inside the nozzle holes;
A protective film attaching step of attaching a protective film to the surface of the water repellent film formed on the discharge side surface of the nozzle forming substrate;
A plasma irradiation step of removing the water-repellent film inside the nozzle hole by plasma treatment;
A protective film peeling step for peeling the protective film from the nozzle forming substrate,
The affixing direction for affixing the protective film to the nozzle forming substrate in the protective film affixing step is in a direction orthogonal to the nozzle hole arrangement direction of the nozzle row configured by the arrangement pattern of the plurality of nozzle holes. A method for manufacturing a droplet discharge head, which is a direction satisfying an angle θ in a range of −10 ° <θ <10 °.   The method for manufacturing a droplet discharge head according to claim 1, wherein the nozzle hole has a quadrangular shape. Forming a plurality of nozzle forming substrate dies in a wafer;
The orientation of the plurality of dies in the wafer is aligned,
Formation of the water repellent film in the water repellent film forming step is performed in a state of a wafer including the plurality of dies,
4. The method for manufacturing a droplet discharge head according to claim 1, wherein the protective film is attached in the state of a wafer including the plurality of dies in the protective film attaching step. 5. A water repellent film forming step of forming a water repellent film on the discharge side surface of the nozzle forming substrate having a plurality of nozzle holes and inside the nozzle holes;
A protective film attaching step of attaching a protective film to the surface of the water repellent film formed on the discharge side surface of the nozzle forming substrate;
A plasma irradiation step of removing the water-repellent film inside the nozzle hole by plasma treatment;
A protective film peeling step for peeling the protective film from the nozzle forming substrate;
A step of manufacturing a droplet discharge head including the nozzle forming substrate via
A relative movement mechanism for relatively moving the manufactured droplet discharge head and a medium to which droplets discharged from the nozzle holes of the droplet discharge head are attached, and the droplet discharge head are arranged in combination. Assembly process;
Have
The attaching direction in which the protective film is attached to the nozzle forming substrate in the protective film attaching step is −10 ° <θ with respect to the relative movement direction of the medium and the droplet discharge head by the relative movement mechanism. <A direction satisfying an angle θ in the range of 10 °,
In the assembling step, the relative movement is performed by satisfying a positional relationship in which an angle between the application direction of the protective film and the relative movement direction by the relative movement mechanism is an angle θ in a range of −10 ° <θ <10 °. An image forming apparatus manufacturing method in which a mechanism and the droplet discharge head are arranged. A water repellent film forming step of forming a water repellent film on the discharge side surface of the nozzle forming substrate having a plurality of nozzle holes and inside the nozzle holes;
A protective film attaching step of attaching a protective film to the surface of the water repellent film formed on the discharge side surface of the nozzle forming substrate;
A plasma irradiation step of removing the water-repellent film inside the nozzle hole by plasma treatment;
A protective film peeling step for peeling the protective film from the nozzle forming substrate;
A step of manufacturing a droplet discharge head including the nozzle forming substrate via
A relative movement mechanism for relatively moving the manufactured droplet discharge head and a medium to which droplets discharged from the nozzle holes of the droplet discharge head are attached, and the droplet discharge head are arranged in combination. Assembly process;
Have
The affixing direction for affixing the protective film to the nozzle forming substrate in the protective film affixing step is in a direction orthogonal to the nozzle hole arrangement direction of the nozzle row configured by the arrangement pattern of the plurality of nozzle holes. A direction satisfying an angle θ in a range of −10 ° <θ <10 °,
In the assembling step, the relative movement mechanism and the liquid droplet ejection head satisfy the positional relationship in which the relative movement direction of the liquid droplet ejection head and the medium by the relative movement mechanism is orthogonal to the nozzle hole arrangement direction. A method of manufacturing an image forming apparatus to be arranged.   7. The single-pass image forming apparatus that completes recording of an image on the medium by a single relative movement of the droplet discharge head and the medium in the relative movement direction. A method for manufacturing an image forming apparatus.   The manufacturing method of the image forming apparatus as described in any one of Claim 5 to 7 which manufactures an image forming apparatus provided with the inkjet head bar which is a line head comprised using the said droplet discharge head.   9. The image according to claim 8, wherein the image forming apparatus includes the inkjet head bar configured by connecting a plurality of head modules as the droplet discharge heads in a width direction of the medium orthogonal to the relative movement direction. Manufacturing method of forming apparatus.   The method of manufacturing an image forming apparatus according to claim 8 or 9, wherein an image forming apparatus including a plurality of the ink jet head bars for discharging the same color ink is manufactured. A nozzle forming substrate having a plurality of nozzle holes;
A water repellent film formed on the discharge side surface of the nozzle forming substrate;
A droplet discharge head comprising:
The water-repellent film around the nozzle hole has a range of −10 ° <θ <10 ° with respect to the relative movement direction of the droplet discharge head and the medium to which the droplet discharged from the nozzle hole is attached. A droplet discharge head in which defective portions of the water repellent film are unevenly distributed in a direction satisfying the angle θ. A nozzle forming substrate having a plurality of nozzle holes;
A water repellent film formed on the discharge side surface of the nozzle forming substrate;
A droplet discharge head comprising:
The water-repellent film around the nozzle holes has an angle in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the nozzle hole arrangement direction of the nozzle row constituted by the arrangement pattern of the plurality of nozzle holes. A droplet discharge head in which defective portions of the water repellent film are unevenly distributed in a direction satisfying θ. A droplet discharge head configured to include a nozzle forming substrate having a plurality of nozzle holes;
An image forming apparatus comprising: a medium for attaching droplets ejected from the nozzle holes of the droplet ejection head; and a relative movement mechanism for relatively moving the droplet ejection head,
A water repellent film is formed on the discharge side surface of the nozzle forming substrate,
The water repellent film around the nozzle hole is in a direction satisfying an angle θ in a range of −10 ° <θ <10 ° with respect to a relative movement direction of the droplet discharge head and the medium by the relative movement mechanism. An image forming apparatus in which defective portions of the water repellent film are unevenly distributed. A droplet discharge head configured to include a nozzle forming substrate having a plurality of nozzle holes;
An image forming apparatus comprising: a medium for attaching droplets ejected from the nozzle holes of the droplet ejection head; and a relative movement mechanism for relatively moving the droplet ejection head,
A water repellent film is formed on the discharge side surface of the nozzle forming substrate,
The water-repellent film around the nozzle holes has an angle in a range of −10 ° <θ <10 ° with respect to a direction orthogonal to the nozzle hole arrangement direction of the nozzle row constituted by the arrangement pattern of the plurality of nozzle holes. An image forming apparatus in which defective portions of the water repellent film are unevenly distributed in a direction satisfying θ.

Images