JP2011031606A - Liquid droplet discharge head, method for manufacturing liquid droplet discharge head, liquid droplet discharge apparatus, and image forming apparatus - Google Patents

Abstract

It is possible to improve the position reproduction accuracy of a droplet discharge head without requiring skill in positioning the droplet discharge head, and to easily and quickly replace the droplet discharge head.
A reference plate having a droplet discharge head is positioned and fixed to a head support base by a positioning unit. The positioning part includes a concave part 61, a groove part 62 and a flat part 63 provided in the reference plate 21 to which the droplet discharge head is fixed. Further, for example, a spherical guide member 64 including the contact, tangent, or contact point of the recess 61, the groove 62, and the flat surface 63 is also included in the positioning portion. Then, each of the concave portion 61, the groove portion 62, and the flat surface portion 63 provided on the reference plate 21 on which the recording head is mounted, and the spherical guide member 64 are tangent or abutting points to each other by urging by the urging means. Abut.
[Selection] Figure 7

Description

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

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, an image of a droplet discharge recording method using a recording head composed of a droplet discharge head (liquid discharge head) that discharges ink droplets An ink jet recording apparatus or the like is known as a forming apparatus. In this droplet discharge recording type image forming apparatus, ink droplets from a recording head are transported on paper (not limited to paper, including OHP, etc., meaning that ink droplets, other liquids, etc. can adhere to them. The recording medium is also called a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). Is. In such an image forming apparatus of a droplet discharge recording system, serial type image formation is performed in which a recording head moves in the main scanning direction, which is a direction orthogonal to the direction in which the paper is transported, to form an image by discharging droplets There are apparatus and a line type image forming apparatus using a line type head that forms an image by ejecting liquid droplets without moving the recording head.

  In the present application, an image forming apparatus of a droplet discharge recording system is an apparatus that forms an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. means. In addition, image formation not only applies an image having a meaning such as a character or a graphic to a medium, but also applies an image having no meaning such as a pattern to the medium (simply landing a droplet on the medium). Meaning). Furthermore, the ink is not limited to the ink, but is used as a general term for all liquids capable of forming an image, such as a recording liquid, a fixing processing liquid, and a liquid, for example, a DNA sample. , Resists, pattern materials, resins, and the like. The image is not limited to a flat image, but includes an image given to a three-dimensional image and an image formed by three-dimensionally modeling a solid itself.

  Conventionally, a technique for positioning in the X, Y, and Z directions has been proposed in Patent Document 1 as a positioning technique for arranging recording heads composed of droplet discharge heads. In Patent Document 1, the head mounting portion for mounting the recording head includes first, second, and third urging means that press the recording head in each of the X, Y, and Z positioning directions. When mounting the recording head on the head mounting portion, the first, second and third urging means press the positioning portions provided on the recording head against the position reference member of the mounted plate. is doing. One of the urging means presses the positioning portion provided on the recording head toward the position reference member of the mounted plate. Such pressing is performed in the three axial directions of the recording head by the first, second and third urging means. Therefore, according to Patent Document 1, the recording head can be easily positioned and fixed in the triaxial direction with respect to the head holding member, and the replacement operation can be performed easily and quickly.

  However, according to the above-mentioned Patent Document 1, the urging means is used to urge the recording head, which is a droplet discharge head, directly against the attached plate and contact the reference surface of the position reference member. For this reason, for example, if there are minute irregularities on the X, Y, and Z reference surfaces that serve as the reference for the recording head, the positioning portion of the recording head may move from the convex portion of the reference surface to the concave portion. At that position, movement by the urging means from another direction is restricted, and the recording head may be slightly rotated from the restricted position to be positioned. In addition, since the movement in the direction along the reference surface is not restricted just by abutting the recording head against the reference surface by the urging means, it is adjusted if an external force acts on the recording head during the replacement work. The position of the recording head may be easily deviated from the position. For this reason, in Patent Document 1, it is difficult to improve the position reproducibility of the recording head by replacement work, and there is a problem that it is not possible to ensure the ejection position accuracy.

  In Patent Document 1, as described above, the positioning portions provided in the recording head with respect to the position reference member of the mounted plate are respectively set by the first, second, and third urging means. Pressing. Therefore, it is necessary to insert the recording head so as to be pushed between the urging means and the positioning portions. In order to insert the head without damaging the head surface, this position adjustment work requires skill, so that a skilled person such as a so-called service person needs to perform adjustment work carefully when replacing the recording head. Therefore, including the confirmation work after the position adjustment of the recording head, there is a disadvantage that the replacement work of the recording head cannot be performed easily and quickly.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve the position reproduction accuracy of the droplet discharge head without requiring skill in positioning the droplet discharge head, Droplet discharge head capable of easily and quickly exchanging the discharge head, a manufacturing method thereof, a droplet discharge device in which the droplet discharge head is positioned with high accuracy, and recording using the droplet discharge device It is an object of the present invention to provide an image forming apparatus capable of forming an image by stably ejecting a recording liquid onto a material without shifting the recording position.

According to a first aspect of the present invention, there is provided a liquid droplet ejection head having a nozzle for ejecting liquid droplets, a head unit having at least one nozzle plate provided with the nozzle, and a head in which the head unit is positioned and detachable. A support base; urging means for urging the head unit against the head support base; and a positioning portion that determines a position of the head unit and the head support base. A concave portion, a groove portion and a flat portion formed on one surface of the surfaces where the unit and the head support base face each other, and a concave portion, a groove portion and a flat portion on the other surface among the opposing surfaces. And a guide member that is formed at each abutting position and that includes at least the abutting line or the abutting point and has a rotation quadratic curved surface. The head unit and the head support base are positioned by the contact lines or the contact points of the guide member and the concave portion, the groove portion, and the flat surface portion being urged by the urging means. A droplet discharge head.
According to a second aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the head unit includes a reference plate on which the liquid droplet ejection head is fixed and the positioning portion is formed. It is characterized by this.
Furthermore, the invention of claim 3 is the droplet discharge head according to claim 1, wherein the head support base is provided in a carriage that reciprocates relative to the droplet discharge material. Is.
According to a fourth aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the head support base fixes the head unit by arranging nozzle rows in a direction perpendicular to the feed direction of the liquid droplet ejection material. It is characterized by doing.
Further, the invention of claim 5 is the droplet discharge head according to claim 1, wherein the concave portion has a conical shape or a triangular pyramid shape.
According to a sixth aspect of the present invention, in the liquid droplet ejection head according to any one of the first to fifth aspects, the groove portion has the same opening angle in the reverse direction with respect to the direction facing the guide member. It is characterized by having two plane parts.
Further, the invention according to claim 7 is the liquid droplet ejection head according to claim 6, wherein the cross-sectional shape of the groove is V-shaped.
An eighth aspect of the present invention is the liquid droplet ejection head according to any one of the first to seventh aspects, wherein the guide member is a sphere.
Furthermore, the invention of claim 9 is the droplet discharge head according to any one of claims 1 to 8, wherein the center of the recess is disposed on an extension line of the center of the groove, and the center of the groove and the center A straight line connecting the centers of the recesses is parallel to the row direction of the nozzle row.
According to a tenth aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the liquid droplet ejection head is fixed to the head unit via an intermediate member screwed into the head unit.
Furthermore, the invention of claim 11 is the liquid droplet ejection head of claim 10, wherein the intermediate member is provided with a through hole.
According to a twelfth aspect of the present invention, in the liquid droplet ejection head according to the tenth aspect, the intermediate member is formed of a member that can transmit UV light.
Furthermore, the invention of claim 13 is the method of manufacturing a droplet discharge head according to any one of claims 1 to 12, wherein the head whole base on which the head unit is positioned and disposed is mounted. A table, and a recess having the same shape as the recess, the groove, and the flat portion provided in the head unit, and a pressing unit provided with the groove and the flat portion in the same arrangement as in the droplet discharge head. Then, the head support base is disposed on the whole head base mounted on the jig table via an adhesive, and the concave portion, the groove portion, and the flat portion provided in the pressing means are provided as guide members on the head support base. With the pressing means, the head support base and the head whole base are pressed and positioned with the pressing means, and the head support base and the upper Joining the head across the base, a method for manufacturing a droplet discharge head is characterized in that positioning the head unit with respect to the head support base.
According to a fourteenth aspect of the present invention, in the method of manufacturing a droplet discharge head according to the thirteenth aspect, the head support base of the head unit is at least a positioning reference in the height direction of the head whole base. Two or more positioning recesses facing each other, and an opening larger than the outer shape of the positioning recess is formed at a position corresponding to the positioning recess in the entire head base, and the above-mentioned through the opening The height of the head support base of the head unit is defined using a loading member loaded in the positioning recess.
Furthermore, the invention of claim 15 is the method of manufacturing a droplet discharge head according to claim 13 or 14, wherein the guide member is attached to the head support base in the joining step of the head support base and the whole head base. Bonding is also performed.
The invention of claim 16 is manufactured by the method of manufacturing a droplet discharge head according to any one of claims 1 to 12 or a droplet discharge head according to any one of claims 13 to 15. A liquid droplet ejection apparatus comprising the above-described liquid droplet ejection head.
Furthermore, the invention of claim 17 is an image forming apparatus comprising the droplet discharge device of claim 16.

  According to the present invention, it is possible to improve the position reproduction accuracy of the droplet discharge head without requiring skill in positioning the droplet discharge head, and it is possible to easily and quickly replace the droplet discharge head. it can. In addition, it is possible to stably discharge the liquid droplets using the liquid droplet discharge apparatus having the liquid droplet discharge head positioned with high accuracy without shifting the liquid discharge position on the material to be discharged. Furthermore, a highly reliable image forming apparatus can be provided by using the droplet discharge device.

1 is a plan view illustrating a configuration of a recording head in an ink jet recording apparatus according to an embodiment of the present invention. It is a top view which shows the structure of the head unit in the inkjet recording device of this Embodiment. It is a top view which shows the structure of the head array unit which mounts the several head unit in the inkjet recording device of this Embodiment. FIG. 2 is a plan view illustrating a configuration of a carriage in the ink jet recording apparatus according to the present embodiment. It is a top view which shows another structure of the carriage in the inkjet recording device of this Embodiment. It is a figure which shows another structure of the head unit in the inkjet recording device of this Embodiment. It is a figure which shows the structure of the positioning part in the inkjet recording device of this Embodiment. It is a perspective view which shows the head support base to which the guide member was fixed. It is a fragmentary sectional view showing the guide member fixed to the head support base. It is a perspective view showing a head unit arranged on a head support base in a subcarriage in the ink jet recording apparatus. It is a block diagram which shows the structure of a head unit assembly apparatus. It is a figure which shows the coordinate of an ideal position, and the center coordinate of a nozzle alignment mark. It is a perspective view which shows the mode of the imaging of the nozzle alignment mark by the CCD camera of a head unit assembly apparatus. It is a perspective view which shows the structure of a reference | standard chart. It is a perspective view which shows the structure of another head support base in the inkjet recording device of this Embodiment. FIG. 2 is a perspective view showing a configuration in which a head unit is mounted on a head support base in a line head type ink jet recording apparatus. It is a top view which shows another structure of the head array unit which mounts the several head unit in the inkjet recording device of this Embodiment. It is a fragmentary sectional view which shows the structure of a part of jig | tool for joining a head support base and the whole head base. It is process sectional drawing which shows the joining process of a head support base and a head whole base. 1 is a schematic configuration diagram illustrating an overall configuration of a mechanism unit of an image forming apparatus according to the present invention. FIG. 2 is a plan view illustrating a main configuration of a mechanism unit of the image forming apparatus according to the present invention. It is a schematic block diagram which shows the whole structure of the mechanism part of the other example of the image forming apparatus which concerns on this invention. It is a top view which shows a subtank integrated type droplet discharge head.

  FIG. 1 is a plan view showing a configuration of a recording head in an ink jet recording apparatus according to an embodiment of the present invention. A recording head in the ink jet recording apparatus according to the present embodiment shown in FIG. The recording head 10 shown in FIG. 1A has one nozzle row 11. Further, the recording head 10 shown in (b) of the figure has two nozzle rows 11, and the recording head 10 shown in (c) of the figure has four nozzle rows 11. As described above, the number of nozzle rows in one recording head 10 is mounted as in one row shown in (a) of the figure or a plurality of rows shown in (b) and (c) in the figure. What is necessary is just to determine suitably according to the model of an inkjet recording device, ie, performance. In the present invention, any recording head can be used. The nozzle holes 12 of the recording head 10 are arranged at equal intervals in the sub-scanning direction. In addition, nozzle alignment marks 13 and 14 are provided at both ends of the nozzle row 11 for use in nozzle position adjustment.

  FIG. 2 is a plan view showing the configuration of the head unit in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The head unit 20 in the ink jet recording apparatus of the present invention has one recording head 10 mounted on one reference plate 21 as shown in FIG. 1A, or shown in FIGS. As described above, a plurality of recording heads 10 are mounted on one reference plate 21. As described above, the number of recording heads bonded on one reference plate differs depending on the model of the ink jet recording apparatus to be mounted, that is, the performance. In the present invention, any number of recording heads may be mounted.

  FIG. 3 is a plan view showing a configuration of a head array unit on which a plurality of head units are mounted in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 2 denote the same components. The head array unit 30 in the ink jet recording apparatus of the present invention shown in the figure is configured by a plurality of head units 20 being detachably arranged in the paper transport direction on the entire head base 31. The number of head units 20 varies depending on the model of the ink jet recording apparatus to be mounted. In the present invention, any number of head units may be mounted.

  FIG. 4 is a plan view showing the configuration of the carriage in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 3 denote the same components. Although two head array units 30 are mounted on the carriage 40 in the ink jet recording apparatus according to the present embodiment shown in the figure, any number of head array units may be mounted. As shown in the figure, two head array units 30 are mounted in the carriage 40, and four head units 20 are detachably mounted on each head array unit 30. Each head unit 20 has one recording head 10 mounted on one reference plate 21. For this reason, when one recording head 10 fails, the head unit 20 mounted on the recording head 10 is replaced.

  FIG. 5 is a plan view showing another configuration of the carriage in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 5 denote the same components. Two head units 20 are mounted on the carriage 40 in the ink jet recording apparatus of the present embodiment shown in FIG. That is, there is no head array unit itself, and the carriage 40 also functions as a head array unit. Each head unit 20 has four recording heads 10 mounted thereon. Therefore, when one recording head 10 fails, the four recording heads 10 in the head unit 20 mounted on the recording head 10 are replaced together.

  FIG. 6 is a diagram showing another configuration of the head unit in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 1 denote the same components. As shown in FIG. 2A, which is a plan view, adjusters 51 are provided as intermediate members at both ends of the recording head 10. The adjuster 51 is provided with an adjuster hole 52. Further, the material of the reference plate 21 may be a metal in consideration of a rigid surface, but a resin having mechanical strength such as polyphenylene sulfide (hereinafter abbreviated as PPS) is preferable in consideration of weight reduction. The recording head 10 and the reference plate 21 are joined by a head unit assembling apparatus to be described later to constitute one head unit. The recording head 10 and the adjuster 51 may be integrated from the beginning or may be bonded. Also, screws may be used. In the case where the screws are fixed, when the recording head 10 breaks down, after the head unit 20 is recovered, only the recording head 10 can be replaced and the other part can be reused.

  FIG. 7 is a diagram showing the configuration of the positioning portion in the ink jet recording apparatus of the present embodiment. (A) of the figure is a plan perspective view, and (b) of the figure is a sectional view taken along line A-A 'of (a) of the figure. As shown in FIGS. 7A and 7B, a positioning portion including a concave portion 61, a groove portion 62, and a flat portion 63 is provided on one surface of the reference plate 21. In the present embodiment, the cavity 61 has a conical shape on the cavity side, and the groove 62 has a V-shaped cross section. Then, three spherical guide members 64 fixed to a predetermined position of the head support base 32 as shown in FIG. 8 are provided on one surface of the reference plate 21 as shown in FIG. The concave portion 61, the groove portion 62, and the flat portion 63 are in contact with each other. Here, the center of the conical recess 61 is arranged on an extension line (indicated by a dotted line in the figure) from the center of the V-shaped groove 62, and the center of the V-shaped groove 62 is The straight line connecting the centers of the conical recesses 61 is arranged in parallel with the nozzle rows 11 of the recording head 10. Even if the distance between the centers of the guide members 64 arranged on the head support base 32 is slightly shifted, the nozzle row 11 can be mounted without causing an inclination, so that the distance between the centers of the guide members 64 of the head support base 32 can be reduced. Tolerances can be relaxed. Since the reference plate 21 and the head support base 32 can be positioned and joined, there is no need to provide a triaxial adjustment mechanism on the main body device on the ink jet recording apparatus side, and the apparatus can be reduced in size and cost.

  The cavity 61 may have a triangular pyramid shape. In the case of the conical shape, the contact portion with the spherical guide member 64 becomes a circular contact line, but with the triangular pyramid shape, the contact portion with the spherical guide member 64 is limited to only three contact points. Therefore, it is difficult to be affected by variations in the shape of the cavity inner wall. Further, the groove portion 62 may not have a V-shaped cross section, and has at least two flat portions having the same opening angle in the reverse direction with respect to the direction facing the guide member 64 that is a sphere. Just do it. Specifically, the bottom surface may be flat and inclined surfaces may be formed on both sides, but at this time, the inclined surface interval needs to be adjusted so that the spherical guide member 64 does not contact the bottom surface. Further, the material of the head support base 32 may be a metal in consideration of a rigid surface, but a resin having mechanical strength such as PPS is preferable in view of weight reduction. The material of the guide member 64 is preferably stainless or ceramic as a material that does not rust. Further, the guide member 64 may be a quadratic curved surface such as a paraboloid, a hyperboloid, an ellipsoid, or the like, including a line or a point in contact with each of the recess 61, the groove 62, and the flat surface 63. In the example of the positioning portion shown in FIG. 7, the concave portion 61, the groove portion 62 and the flat portion 63 are provided on the reference plate 21 and the guide member 64 is provided on the head support base 32. 63 may be provided on the head support base 32 and the guide member 64 may be provided on the reference plate 21.

  Further, as shown in FIG. 9, the spherical guide member 64 is mounted on the head support base 32 on a guide member support portion 65 having a shape that has been drilled and chamfered, and is then adhered by an adhesive 66. It has a structure. The arrangement accuracy of the spherical guide member 64 depends on the position accuracy of the hole processing. Further, the positional accuracy of the spherical guide member 64 in the vertical direction depends on the amount of chamfering. However, as described above, in the conical concave portion 61, the V-shaped groove portion 62, and the flat surface portion 63 on the bottom surface of the reference plate 21, the conical concave portion 61 is formed on the extension line from the center of the V-shaped groove portion 62. Further, a straight line connecting the center of the V-shaped groove 62 and the center of the conical recess 61 is parallel to the nozzle row 11 of the recording head 10, so that the gap between the center of the spherical guide member 64 and the spherical guide member 64 can be reduced. There is no need to tighten dimensional tolerances. Even when there is an error in the dimension between the guide members 64 of the sphere, the initial position in the plane is determined by the conical recess 61, and an extension line between the center of the conical recess 61 and the center of the V-shaped groove 62 is formed. Since it is parallel to the nozzle row 11, it can be defined so that no inclination occurs in the arrangement direction of the nozzle row 11. Further, the head support base 32 is basically subjected to the same hole diameter and chamfering process, and the three spherical guide members 64 provided on the head support base 32 are also used with the same diameter. The amount of protrusion from the surface of the head support base 32 is the same. Further, when the concave portion 61, the groove portion 62, and the flat portion 63 provided in the reference plate 21 are aligned with a spherical guide member 64 having the same diameter and the same amount of protrusion, the upper surface of the head support base 32 and the recording head are arranged. 10 planes are placed in parallel.

  FIG. 10 is a perspective view showing a configuration of a head unit disposed on the head support base. As shown in the figure, four head units 20 are detachably installed on a head support base 32 of the head array unit 30. Further, spherical guide members 64 are fixed at predetermined positions of the head support base 32. Further, one recording head 10 is attached to one head unit 20. In this case, since it can be attached and detached in units of head units, if one recording head 10 fails, only one head unit needs to be replaced.

Here, the procedure for replacing the head unit will be described below with reference to FIG.
First, an ink supply tube (not shown) for supplying ink to the recording head 10 is removed. Next, the head unit 20 can be removed by lifting the upper biasing means (not shown) and moving it upward to release the bias, and then lifting the head unit 20 to be replaced due to failure to remove it. it can. Next, the mounting of the new head unit 20 is performed by aligning the positions of the three spherical guide members 64 on the head support base 32 with the positions of the recesses, grooves and planes of the reference plate 21 in the head unit 20, respectively. The head unit 20 is attached by lowering the upper biasing means (not shown) and biasing it from above. The nozzle position after replacement can complete positioning in the XYZ triaxial directions only by this operation. Since the head unit assembling apparatus is assembled in the same state as that attached to the ink jet recording apparatus main body, the positional relationship between the head support base and the nozzle row can be reproduced. Finally, an ink supply tube for supplying ink to the recording head is attached. The head unit replacement operation is thus completed.

  FIG. 11 is a block diagram showing the configuration of the head unit assembling apparatus. A head unit assembling apparatus 100 shown in the figure is an apparatus for assembling a head unit by joining four recording heads to one reference plate 21. The head unit assembly apparatus 100 mainly includes a holding unit 101, a positioning unit 102, a table moving unit 103, a control unit 104, and an image processing unit 105. According to the head unit assembling apparatus 100, the arm 109 for adjusting the vertical and horizontal positions of the respective recording heads 106 and for gripping the holes 108 of the adjusters 107 provided in the recording heads 106. By using the positioning unit 102 for positioning the position of the arm unit 109, each recording head 106 can be moved to a predetermined position in the vertical direction and the horizontal direction. Further, the table moving unit 103 includes a table (not shown) that moves by mounting the holding unit 101 that holds the recording head 10 and the reference plate 21, and this table is used for the CCD cameras 110 and 111 that are imaging means. Move to a position where it can be imaged. The control unit 104 includes a table position detection unit 104-1, a position adjustment unit 104-2, an adhesive application unit 104-3, a table movement control unit 104-4, a target position calculation unit 104-5, and an ideal position registration unit. 104-6. The table position detection unit 104-1 detects the position of the table of the table moving unit 103. The position adjustment unit 104-2 controls the positioning unit 102. The adhesive application unit 104-3 fills the adhesive between the adjuster 107 and the reference plate 21. The table movement control unit 104-4 controls the table movement unit 103. Further, as shown in FIG. 15, the target position calculation unit 104-5 has the coordinates (xa, ya) of the ideal position a registered in the ideal position registration unit 104-6 and the center coordinates (XA, YA) and the difference between the coordinates (xb, yb) of the ideal position b and the center coordinates (XB, YB) of the nozzle alignment mark B, and the distance from the nozzle alignment marks A, B to the ideal positions a, b is calculated. To do. The ideal position transferred from the image processing unit 105 is registered in the ideal position registration unit 104-6. The table position detection unit 104-1, the position adjustment unit 104-2, the adhesive application unit 104-3, the table movement control unit 104-4, the target position calculation unit 104-5, and the ideal position registration unit 104-6 The operation unit 112 can be operated. On the other hand, the image processing unit 105 includes CCD cameras 110 and 111, coaxial incident illumination units 105-1 and 105-2, a monitor 105-3, an operation unit 105-4, an image processing and nozzle alignment mark position measurement unit 105-5, and an ideal. A position measurement unit 105-6 is provided. As shown in FIG. 13, the CCD cameras 110 and 111 image the vicinity of the nozzle alignment marks 13 and 14 provided on the recording heads 201 mounted on the carriage 200, and the coaxial incident illumination units 105-1 and 105-2. Illuminates the nozzle alignment marks 13 and 14 and the vicinity thereof. The CCD cameras 110 and 111 according to the present embodiment acquire images by photographing the vicinity of the nozzle alignment marks 13 and 14 from a direction perpendicular to the head surface on which the nozzle alignment marks 13 and 14 are formed. For this reason, CCD cameras 110 and 111 having a measurement visual field of 1.2 mm horizontal by 0.9 mm vertical and a subject depth of ± 110 microns are used.

  The monitor 105-3 displays the nozzle alignment marks 13, 14 and the like captured by the CCD cameras 110, 111. The image processing and nozzle alignment mark position measuring unit 105-5 performs a series of image processing based on the image data in the vicinity of the nozzle alignment marks 13 and 14 photographed by the CCD cameras 110 and 111, and the nozzle alignment marks 13 and 14 are scanned. Detect position. Specifically, the optimal illumination dimming is performed by calculating the average density of the image, the optimal binarization is determined, and the nozzle alignment to be used as a position reference based on conditions such as area value, width, height, and circularity The marks 13 and 14 are specified.

  In the present embodiment, as shown in FIG. 12, the center coordinates (XA, YA) of the nozzle alignment mark A and the center coordinates (XB, YB) of the nozzle alignment mark B are measured and data is output to the control unit 104. . These series of processes are configured by an image processing system that is activated by incorporating a part of dedicated hardware and software into a general-purpose information device. In this embodiment, an optical image portion having a pixel resolution of 1.6 microns / pixel is provided, and the measurement accuracy is 0.5 microns by gray processing which is a general software processing.

  The ideal position measurement unit 105-6 acquires the ideal position from the ideal position acquisition unit 113 in which the ideal position is recorded. Specifically, calibration is performed using a reference chart 300 configured by attaching a glass plate 301 on which ideal positions a and b are recorded as shown in FIG. The reference chart 300 is accurately formed with micron accuracy at the ideal dimensions of the positions of the nozzle alignment marks of the recording head, and the ideal position a and the ideal position b are accurately recorded there with micron accuracy. A glass plate 301 is bonded.

  The reference chart 300 is attached to the head unit assembling apparatus 100 in FIG. 11 instead of the head unit, and the ideal positions a and b are determined by the CCD cameras 110 and 111 based on the signal from the target position calculation unit 104-5 of the control unit 104. Images are taken, and the ideal positions a and b are measured by the ideal position measuring unit 105-6. Then, the ideal position measurement unit 105-6 transfers this measurement result to the control unit 104, and registers this measurement result in the ideal position registration unit 104-6. In order to attach the reference chart 300 of FIG. 14 instead of the reference plate 21, the base material constituting the reference chart 300 is provided with a concave portion, a groove portion, and a flat portion on the bottom surface in the same manner as the reference plate 21. In the present embodiment, the ideal positions a and b are acquired from the reference chart 300 by the ideal position measurement unit 105-6. In this way, when adjusting the position of a plurality of recording heads, each recording head is positioned at the ideal position without being affected by mechanical errors when the head unit assembly apparatus is moved to the adjustment start position. Can be moved reliably.

  Next, the support state of the reference plate and the recording head placed on the head unit assembling apparatus will be described. The holding unit 101 in FIG. 11 can hold the reference plate 21 and the recording head. The reference plate 21 is placed on three spheres provided at predetermined positions on the base of the holding unit 101 so as to be aligned with the concave portion, the groove portion, and the flat portion on the bottom surface thereof, and has an upper portion in the vertical direction. It is pressurized and fixed from above by the biasing means. At this time, the base of the holding unit 101 in the head unit assembling apparatus has three spheres arranged at the same size and the same location as the head support base constituting the sub-carriage. That is, the state of the reference plate 21 held on the head unit assembling apparatus is reproduced on the sub-carriage as it is. Next, the recording head is temporarily fixed with the nozzle holes positioned below.

  In this embodiment, adjusters are provided on both sides of each recording head. The adjusters are engaged with engaging portions provided on the reference plate, and are applied using upper biasing means that presses from above. By energizing, the restriction of the downward movement of each recording head is temporarily fixed in the left and right front-rear direction by the frictional force, and the positions of the nozzle holes of the respective recording heads on the horizontal plane coincide with each other. Each recording head can be adjusted in position by moving it forward, backward, left and right by holding and moving the adjuster while the adjuster is pressed against the engaging member by the upper biasing means. In addition, each recording head is provided with nozzle alignment marks as objects at both ends in the sub-scanning direction, and the nozzle holes of the recording head are nozzles that are perpendicular to the reference axis set on the reference plate. The position can be adjusted with a desired accuracy with reference to the alignment mark, and the first nozzle holes of the respective recording heads can be adjusted with a desired accuracy and a desired distance from the reference axis.

Next, the process of assembling the head unit of the head unit assembling apparatus will be described.
The assembly operation by the head unit assembling apparatus 100 in FIG. 11 is performed by causing the control unit 104 to execute a program stored in a storage unit (not shown) provided in the control unit 104. First, when the power of the head unit assembly apparatus 100 is inserted, the origin is returned to determine the origin of the head unit assembly apparatus 100. Next, the registered ideal positions a and b are acquired. The reference plate 21 is fixed to the base of the holding unit 101. A UV adhesive is applied in advance on the engaging member provided on the reference plate 21 using the adhesive application unit 104-3. The adjuster 107 of the recording head 106 is gripped by fitting a pin at the tip of the arm of the position adjusting unit 104-2 into an adjuster hole 108 in an adjuster 107 provided on both sides of the temporarily fixed recording head 106. Start adjustment. The position of the recording head 106 is adjusted by moving the recording head 106 back and forth and left and right in a state where the adjuster 107 is pressed against the engaging member by the upper biasing means. Next, as shown in FIG. 13, the vicinity of the nozzle alignment marks 13 and 14 is simultaneously imaged by the CCD cameras 110 and 111.

  Next, the positions of the nozzle alignment marks 13 and 14 are detected by the image processing and nozzle alignment mark position measuring unit 105-5. At this time, the optimal illumination of the coaxial epi-illumination units 105-1 and 105-2 is adjusted from the average density calculation of the image, and the optimal binarization is determined, and the area value, width, height, and circularity are determined. From the above conditions, the nozzle alignment marks 13 and 14 to be used as the position reference are specified. In the present embodiment, since the reflecting plate is embedded in the bottom surface of the nozzle alignment marks 13 and 14, the nozzle alignment marks 13 and 14 can be easily identified. Next, based on the difference between the detected position data of the coordinates of the nozzle alignment marks 13 and 14 and the position data of the coordinates of the ideal positions a and b acquired in advance before assembling the head unit, the ideal The target positions of the nozzle alignment marks 13 and 14 up to the positions a and b are calculated. Next, the position adjustment unit 104-2 in FIG. 11 moves the recording head 106 in the horizontal and vertical directions via the adjuster 107 so that the ideal positions a and b coincide with the detected nozzle alignment marks 13 and 14. The position is adjusted by moving the distance of the target position. In this way, by adjusting the position so that the two ideal positions a and b and the nozzle alignment marks 13 and 14 coincide with each other, the respective recording heads 106 are placed on the reference plate 21 with reference to the nozzle alignment marks 13 and 14. It can be positioned with high accuracy. When the position adjustment is completed, the adjuster 107 in the recording head 106 and the engaging member provided in the reference plate 21 are bonded with a UV adhesive by irradiating with UV from a UV irradiator disposed on the adjuster 107. Can do. At this time, by making the member of the adjuster 107 a transparent member, it is possible to transmit UV light and irradiate the UV adhesive. When the bonding of one recording head is completed, the remaining recording heads are bonded repeatedly in the above procedure. In this embodiment, the case where the adjuster is used as an intermediate member on both sides of the recording head has been described. However, the recording head and the adjuster may be integrated.

  FIG. 15 is a perspective view showing the configuration of another head support base in the ink jet recording apparatus of the present embodiment. A head support base 32 shown in the figure is a head support base applied when the ink jet recording apparatus as shown in FIG. 16 is a line head type. As shown in FIG. 15, the head support base 32 includes three spheres 64 provided at positions corresponding to the concave portions, the groove portions, and the flat portion provided on one surface of the reference plate with respect to each head unit, Upper urging means (not shown) for urging in the vertical direction is arranged. By arranging a plurality of head units on the head support base 32, as shown in FIG. 16, a plurality of nozzle arrays are arranged on the long head support base 32 in a direction orthogonal to the paper feed direction. The head unit 20 is fixed. The head unit 20 can be attached to and detached from the head support base 32 as shown in FIG.

  FIG. 17 is a plan view showing another configuration of a head array unit on which a plurality of head units are mounted in the ink jet recording apparatus of the present embodiment. In the figure, the same reference numerals as those in FIG. 3 denote the same components. The head array unit 30 in the ink jet recording apparatus of the present embodiment shown in the figure is configured by a plurality of head units 20 being detachably arranged on the entire head base 31 in the paper transport direction. Also in the example shown in the figure, the number of head units 20 varies depending on the model of the ink jet recording apparatus to be mounted. The head array unit 30 shown in the figure can be applied to either a serial type or a line type ink jet recording apparatus. Here, an example applied to a line type ink jet recording apparatus will be described. In the head array unit 30 in the figure, three head units 20 arranged in a line in the vertical direction in the figure and three head units 20 arranged alternately in the front line form an image of one color. One recording unit composed of six head units 20 surrounded by dotted lines in the figure is arranged for each color in the conveyance direction in which the recording material is conveyed in the arrow direction in the figure. Are arranged in According to the line type ink jet recording apparatus including the head array unit 30 having such a configuration, each pixel in each column is provided by the recording unit provided for each color on the recording material conveyed in the conveying direction. The recording liquid of each color is ejected to form an image.

  In the process of assembling the head array unit 30 shown in FIG. 17, in order to improve the nozzle arrangement accuracy between the plurality of head units 20 provided on the head whole base 31, the head support base 32 positioned on the head whole base 31 is arranged. Each reference unit 21 of each head unit 20 is pressed and fixed to position at least the XY plane between the head units 20. Hereinafter, a configuration of a jig for joining the head support base 32 to the head whole base 31 and a process of joining the head whole base and the head support base using the jig will be described.

  FIG. 18 is a partial cross-sectional view showing a configuration of a part of a jig for joining the head support base and the entire head base. A part of the configuration of the jig 600 shown in the figure is a configuration in which one of the plurality of head support bases is joined to the entire head base. The jig 600 mainly includes a jig base 601 on which the entire head base is installed, a plurality of linear motion guides 602, and a jig movable table 603. The jig base 601 includes an entire head base (not shown), has an installation surface facing the jig movable table 603, and has an opening 601-1 into which a stepped pin 604 is inserted in advance. Yes. Each linear guide 602 includes a base 602-1 and a lifting shaft 602-2, and the base 602-1 is installed on the jig base 601. The end of the lifting shaft 602-2 is attached to the jig movable table 603. The amount of vertical movement by each linear guide 602 is controlled to be the same. Further, on the surface of the jig movable table 603 facing the jig base, each guide member 64 provided on each head support base (not shown) installed on the entire head base is provided at each installation position. At the corresponding positions, a recess 605, a V-shaped groove 606, and a flat portion 607 similar to those provided on each reference plate are provided.

Next, FIG. 19 shows a process of installing and bonding a plurality of head support bases on the entire head base using the jig 600 having such a configuration.
In (a) of the figure, the elevating shaft 602-2 of each linear guide 602 in the jig 600 is raised to open a large gap between the jig base 601 and the jig movable table 603. This is because the entire head base 31 and further each head support base 32 to be described later can be arranged on the jig base 601. A stepped pin 604 is inserted into each opening 601-1 of the jig base 601. Then, the entire head base 31 is set on the jig base 601. During the installation, each opening 31-1 provided in advance in the head overall base 31 passes through each stepped pin 604. Thereby, the installation position of the whole head base 31 can be determined. Thereafter, a UV adhesive 608 is applied to the head region on the entire head base 601 where the head support bases are installed. Next, as shown in FIG. 5B, each head support base 32 is installed at a predetermined position on the entire head base 601. Then, the concave portion 605, the V-shaped groove portion 606, and the flat portion 607 of the jig movable table 603 abut against the spherical guide member 64, and each head support base 32 is uniformly pressed against the entire head base 31. Until then, the jig moving table 603 is lowered by driving the elevating shaft 602-2 of each linear guide 602 in the downward direction. Then, the upper end portion of the stepped pin 604 is inserted into a pin hole 21-1 provided at a predetermined position of each head support base 32. The depth of the pin hole 21-1 is a value that serves as a reference for the mounting position of the head support base 32 in the vertical direction (Z-axis direction) when the upper end surface of the stepped pin 604 contacts. Further, the hole area of the pin hole 21-1 is larger than the area of the upper end face of the stepped pin 604, and the stepped pin 604 in the pin hole 21-1 is movable in the XY axis direction. Therefore, there is no restriction due to the presence of the stepped pin 604 for at least fine adjustment in the XY axis direction in the XYZ axis positioning. Then, as shown in FIG. 4D, after the upper end surface of each stepped pin 604 comes into contact with the bottom surface of each pin hole 21-1 of each reference plate 21, the head support base 32 and the entire head base The jig movable table 603 is pressed for fine adjustment of the XYZ-axis positioning in the joining with 31. Finally, the UV adhesive 608 applied between each head support base 32 and the entire head base 31 is irradiated with UV to be cured, and each head support base 32 and the entire head base 31 are joined. Thereafter, although not shown in the drawing, the lifting and lowering shaft 602-2 of each linear guide 602 is driven in the upward direction to raise the jig movable table 603, whereby the joining is completed, and each head support base 32 is joined. The entire head base 31 is taken out. As described above, since the stepped pin 604 only regulates the depth direction of the pin hole 21-1, the stepped pin 604 is not involved in the removal of the entire head base 31.

  Here, the step of bonding to the entire head base using the head support base 32 to which the guide member 64 is already attached has been shown, but the step of bonding the guide member 64 to the head support base can also be used. In this case, the guide member can be fixed by lowering and pressing the jig movable table 603 while applying the adhesive to the guide member support portion 65 and placing the guide member 64 thereon, and curing the adhesive.

  The upper end surface of the stepped pin 604 is polished with the lower surface of the reference plate 21 as a reference, and the protrusion amount from the entire head base 31 on all stepped pin upper end surfaces is processed to have the same dimension. Has been. Further, the material of the reference plate 21 may be a metal in consideration of a rigid surface, but a resin-based material having mechanical strength such as polyphenylene sulfide or a composite material of ceramic and resin is preferable in view of weight reduction. The material of the attachment reference member is preferably a lightweight metal such as aluminum, which has mechanical strength and is lightweight because the threaded portion is attached and detached as the recording head is replaced. Further, a reaction initiator (primer) is applied to the reference plate 21 side in advance to contact the UV adhesive 608 applied to the entire head base 31 to accelerate the start of curing and shorten the curing time. Also good.

  Next, an example of the image forming apparatus according to the present invention will be described with reference to FIGS. 20 is a schematic configuration diagram showing the overall configuration of the mechanism section of the image forming apparatus according to the present invention, and FIG. 21 is a plan view showing the configuration of the main section of the mechanism section of the image forming apparatus according to the present invention.

  This image forming apparatus is a serial type image forming apparatus, and a carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. The main scanning motor that does not perform moving scanning in the direction indicated by the arrow (carriage main scanning direction) via the timing belt.

  The carriage 233 includes a droplet discharge head according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K), and a drive signal to the head. A recording head 234 composed of a droplet discharge head unit in which an electric circuit board for supplying ink and a tank for storing ink to be supplied to the head are integrated into a sub-scanning direction orthogonal to the main scanning direction. They are arranged and mounted with the ink droplet ejection direction facing downward.

  The recording head 234 is configured by attaching droplet discharge head units 234a and 234b each having two nozzle rows to one base member, and one nozzle row of one head 234a is a black (K) droplet. The other nozzle row is a cyan (C) droplet, the other nozzle row of the other head 234b is a magenta (M) droplet, and the other nozzle row is a yellow (Y) droplet. Discharge. Here, a configuration in which droplets of four colors are ejected in a two-head configuration is used, but it is also possible to arrange four nozzle rows per head and eject each of the four colors with one head.

  Further, the ink of each color is replenished and supplied from the ink cartridge 210 of each color to the tank 235 of the recording head 234 via the supply tube 236 of each color.

  On the other hand, as a paper feed unit for feeding the paper 242 loaded on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon roller (feed) that feeds the paper 242 from the paper stacking unit 241 one by one. A separation pad 244 made of a material having a large coefficient of friction is provided opposite to the sheet roller 243 and the sheet feeding roller 243, and the separation pad 244 is urged toward the sheet feeding roller 243 side.

  In order to feed the sheet 242 fed from the sheet feeding unit to the lower side of the recording head 234, a guide member 245 for guiding the sheet 242, a counter roller 246, a conveyance guide member 247, and a tip pressure roller. And a conveying belt 251 which is a conveying means for electrostatically attracting the fed paper 242 and conveying it at a position facing the recording head 234.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction). In addition, a charging roller 256 that is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 256 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251. The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 242 recorded by the recording head 234, a separation claw 261 for separating the paper 242 from the transport belt 251, a paper discharge roller 262 and a paper discharge roller 263 are provided. A paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body. The duplex unit 271 takes in the paper 242 returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, in the non-printing area on one side in the scanning direction of the carriage 233, the maintenance / recovery mechanism 281 which is a head maintenance / recovery device according to the present invention including a recovery means for maintaining and recovering the nozzle state of the recording head 234. Is arranged. The maintenance / recovery mechanism 281 includes cap members (hereinafter referred to as “caps”) 282a and 282b (hereinafter referred to as “caps 282” when not distinguished) for capping each nozzle surface of the recording head 234, and nozzle surfaces. A wiper blade 283 that is a blade member for wiping the ink, and an empty discharge receiver 284 that receives liquid droplets for discharging the liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing.

  Further, in the non-printing area on the other side in the scanning direction of the carriage 233, there is an empty space for receiving a liquid droplet when performing an empty discharge for discharging a liquid droplet that does not contribute to the recording in order to discharge the recording liquid thickened during the recording. A discharge receiver 288 is disposed, and the idle discharge receiver 288 is provided with an opening 289 along the nozzle row direction of the recording head 234 and the like.

  In the image forming apparatus having such a configuration, the sheets 242 are separated and fed one by one from the sheet feed tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and includes the transport belt 251 and the counter. It is sandwiched between the rollers 246 and conveyed, and further, the leading end is guided by the conveying guide 237 and pressed against the conveying belt 251 by the leading end pressing roller 249, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately applied to the charging roller 256, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 251 alternates, that is, in the sub-scanning direction that is the circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 242 is fed onto the conveyance belt 251 charged alternately with plus and minus, the sheet 242 is attracted to the conveyance belt 251, and the sheet 242 is conveyed in the sub scanning direction by the circumferential movement of the conveyance belt 251.

  Therefore, by driving the recording head 234 according to the image signal while moving the carriage 233, ink droplets are ejected onto the stopped paper 242 to record one line, and after the paper 242 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 242 has reached the recording area, the recording operation is finished and the paper 242 is discharged onto the paper discharge tray 203.

  Thus, in this image forming apparatus, since the liquid droplet ejection head according to the present invention is provided as a recording head, the reliability is improved.

Next, another example of the image forming apparatus according to the present invention will be described with reference to FIG. FIG. 22 is a schematic configuration diagram showing the overall configuration of the mechanical unit of another example of the image forming apparatus according to the present invention.
This image forming apparatus is a line type image forming apparatus, has an image forming unit 402 and the like inside the apparatus main body 401, and can supply a large number of recording media (sheets) 403 on the lower side of the apparatus main body 401. A paper tray 404 is provided, a sheet 403 fed from the sheet feeding tray 404 is taken in, a required image is recorded by the image forming unit 402 while the sheet 403 is conveyed by the conveying mechanism 405, and then the side of the apparatus main body 401. The paper 403 is discharged to a paper discharge tray 406 attached to the printer.

  Also, a duplex unit 407 that can be attached to and detached from the apparatus main body 401 is provided, and when performing duplex printing, the sheet 403 is conveyed into the duplex unit 407 while being transported in the reverse direction by the transport mechanism 405 after one-side (front) printing is completed. Then, the other side (back side) is sent back to the transport mechanism 405 as the printable side, and the paper 403 is discharged to the paper discharge tray 406 after the other side (back side) printing is completed.

  Here, the image forming unit 402 ejects droplets of each color of yellow (Y), magenta (M), cyan (C), and black (K), for example, four line type droplets according to the present invention. Each recording head 411 includes recording heads 411y, 411m, 411c, and 411k (hereinafter referred to as “recording heads 411” when colors are not distinguished), which are configured by integrating an ejection head and a sub tank that supplies ink to the droplet ejection head. Is attached to the head holder 413 with the nozzle surface on which nozzles for discharging droplets are formed facing downward.

  As shown in FIG. 23, one recording head 411 includes a plurality of (six in this example) sub tank integrated liquid droplet ejection heads 501A to 501F according to the present invention in a predetermined positional relationship with the base member 502. Although it is configured by arranging, it can also be configured by one full line type droplet discharge head.

  In addition, a maintenance / recovery mechanism 412y, 412m, 412c, 412k (referred to as “maintenance / recovery mechanism 412” when colors are not distinguished) corresponding to each recording head 411 is provided to maintain and recover the performance of the head. During the head performance maintenance operation such as wiping processing, the recording head 411 and the maintenance / recovery mechanism 412 are relatively moved so that the capping member constituting the maintenance / recovery mechanism 412 faces the nozzle surface of the recording head 411.

  The paper 403 in the paper feed tray 404 is separated one by one by a paper feed roller (half-moon roller) 421 and a separation pad (not shown) and fed into the apparatus main body 401, and is registered along the guide surface 423 a of the transport guide member 423. It is sent between 425 and the conveyor belt 433, and is sent to the conveyor belt 433 of the conveyor mechanism 405 via the guide member 426 at a predetermined timing.

  The conveyance guide member 443 is also formed with a guide surface 423 b for guiding the paper 403 sent out from the duplex unit 407. Further, a guide member 427 for guiding the sheet 403 returned from the transport mechanism 405 to the duplex unit 407 during duplex printing is also provided.

  The conveyance mechanism 405 includes an endless conveyance belt 433 that is stretched between a conveyance roller 431 that is a driving roller and a driven roller 432, a charging roller 434 that charges the conveyance belt 433, and an image forming unit 402. A platen member 435 that maintains the flatness of the conveyance belt 433 at the opposite portion, a pressing roller 436 that presses the paper 403 fed from the conveyance belt 433 against the conveyance roller 431 side, and other recording liquid that is attached to the conveyance belt 433, although not shown. It has a cleaning roller made of a porous material or the like, which is a cleaning means for removing (ink). As the transport mechanism, for example, a mechanism that sucks the recording medium onto the transport belt by air suction can be used.

  On the downstream side of the transport mechanism 405, a paper discharge roller 438 and a spur 439 for sending the paper 403 on which an image is recorded to the paper discharge tray 406 are provided.

  In the image forming apparatus configured as described above, the conveyance belt 433 moves in the direction indicated by the arrow and is charged by contact with the charging roller 434 to which a high applied voltage is applied. When 403 is fed, the sheet 403 is electrostatically attracted to the conveyance belt 433. In this way, the sheet 403 that is strongly adsorbed to the transport belt 433 is calibrated for warpage and unevenness, and forms a highly flat surface.

  Then, the paper 403 is moved around the conveyor belt 433 and droplets are ejected from the recording head 411, whereby a required image is formed on the paper 403, and the paper 403 on which the image has been recorded is the paper discharge roller 438. As a result, the paper is discharged to the paper discharge tray 406.

  As described above, since the image forming apparatus includes the droplet discharge head according to the present invention, the reliability is improved.

  In the above embodiment, the present invention has been described with reference to an example in which the present invention is applied to an image forming apparatus having a printer configuration. However, the present invention is not limited to this, and as described above, for example, image forming such as a printer / fax / copier multifunction device. The present invention can be applied to an apparatus, and as described above, the present invention can also be applied to an image forming apparatus that uses a liquid other than a narrowly defined ink or a fixing processing liquid.

  As described above, according to the present embodiment, as shown in FIG. 7, the reference plate 21 having the recording head is positioned and fixed to the head support base 32 by the positioning unit. The positioning part includes a recess 61, a groove part 62, and a flat part 63 provided in the reference plate 21 to which the recording head is fixed. Further, for example, a spherical guide member 64 including a contact point, a tangent line, or a contact point of the concave portion 61, the groove portion 62, and the flat surface portion 63 is also included in the positioning portion. Then, each of the concave portion 61, the groove portion 62, and the flat surface portion 63 provided on the reference plate 21 on which the recording head is mounted, and the spherical guide member 64 are tangent or abutting points to each other by urging by the urging means. Abut. In this way, the urging force by the urging means is applied to the concave portion 61, the groove portion 62, and the flat surface portion 63 through the spherical guide member, and the reference of the position reference member provided on the casing surface of the recording head or the recording head. The surface is not directly biased by the biasing means. Therefore, the recording head can be easily and quickly replaced with high accuracy regardless of the positioning of the recording head in the three-axis directions regardless of the unevenness of the casing surface of the recording head or the reference surface of the position reference member. be able to.

  Further, as shown in FIG. 6, the recording head is fixed to a reference plate 21 constituting a head unit using an adjuster 51 that is an intermediate member screwed to the recording head. Therefore, the recording head can be easily replaced while the adjuster 51 is held and positioned.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and substitutions are possible as long as they are described within the scope of the claims.

10, 234, 411 Recording head 11 Nozzle array 12 Nozzle hole 13, 14 Nozzle alignment mark 20 Head unit 21 Reference plate 30 Head array unit 31 Whole head base 32 Head support base 40 Carriage 51 Adjuster 52 Adjuster hole 61, 605 Concave 62, 606 Groove parts 63, 607 Plane part 64 Guide member 65 Guide member support part 66 Adhesive 100 Head unit assembly device 300 Reference chart 600 Jig 601 Jig base 602 Direct acting guide 603 Jig movable table 604 Stepped pin 608 UV adhesive

JP 2006-231802 A

Claims (17)

In a droplet discharge head equipped with a nozzle for discharging droplets,
A head unit having at least one nozzle plate provided with the nozzle;
A head support base on which the head unit is positioned and detachable;
Biasing means for biasing the head unit against the head support base;
A positioning portion for determining the position of the head unit and the head support base;
The positioning portion includes a concave portion, a groove portion and a flat portion formed on one surface of the surfaces facing the head unit and the head support base, and the concave portion and the groove portion on the other surface among the facing surfaces. And a guide member that is formed at a position that abuts on each of the plane portions, and that includes at least a contact line or a contact point, and a guide member having a rotating quadratic curved surface.
The head unit and the head support base are positioned by abutting a contact line or a contact point of the guide member with the concave portion, the groove portion, and the flat portion by biasing by the biasing means. Droplet discharge head. The droplet discharge head according to claim 1,
The liquid droplet ejection head, wherein the head unit includes a reference plate on which the liquid droplet ejection head is fixed and the positioning portion is formed. The droplet discharge head according to claim 1,
The liquid droplet ejection head, wherein the head support base is provided in a carriage that reciprocates relative to the liquid droplet ejection material. The droplet discharge head according to claim 1,
The liquid droplet ejection head, wherein the head support base fixes the head unit by arranging nozzle rows in a direction perpendicular to a feeding direction of the liquid droplet ejection material. The droplet discharge head according to claim 1,
The liquid droplet ejection head, wherein the concave portion has a conical shape or a triangular pyramid shape. In the droplet discharge head according to any one of claims 1 to 5,
The liquid droplet ejection head, wherein the groove has two flat portions having the same opening angle in opposite directions with respect to a direction facing the guide member. The droplet discharge head according to claim 6, wherein
A droplet discharge head characterized in that a cross-sectional shape of the groove portion is V-shaped. In the droplet discharge head according to any one of claims 1 to 7,
The liquid droplet ejection head, wherein the guide member is a sphere. In the droplet discharge head according to any one of claims 1 to 8,
The droplet discharge head, wherein the center of the recess is disposed on an extension line of the center of the groove, and a straight line connecting the center of the groove and the center of the recess is parallel to the row direction of the nozzle row. . The droplet discharge head according to claim 1,
A droplet discharge head characterized by being fixed to the head unit via an intermediate member screwed to the head unit. The droplet discharge head according to claim 10,
A liquid droplet ejection head, wherein the intermediate member is provided with a through hole. The droplet discharge head according to claim 10,
The droplet discharging head according to claim 1, wherein the intermediate member is made of a member that can transmit UV light. In the manufacturing method of the droplet discharge head according to any one of claims 1 to 12,
A jig table on which the entire head base on which the head unit is positioned and mounted is mounted, and the concave portion, the groove portion, and the flat portion that have the same shape as the concave portion, the groove portion, and the flat portion provided in the head unit. Pressing means provided in the same arrangement as the arrangement in the droplet discharge head,
The head support base is disposed via an adhesive on the entire head base mounted on the jig table,
With the concave portion, groove portion and flat surface portion provided in the pressing means facing the guide members on the head support base, the head support base and the whole head base are pressed and positioned by the pressing means. , Joining the head support base and the whole head base;
A method of manufacturing a droplet discharge head, wherein the head unit is positioned with respect to the head support base. In the manufacturing method of the droplet discharge head according to claim 13,
The head support base of the head unit has at least two positioning recesses facing the head overall base serving as a positioning reference in the height direction of the head overall base. An opening larger than the outer shape of the positioning recess is formed at a position corresponding to, and the height of the head support base of the head unit is defined using a loading member that is loaded into the positioning recess through the opening. A method of manufacturing a droplet discharge head. In the manufacturing method of the droplet discharge head according to claim 13 or 14,
A method of manufacturing a droplet discharge head, wherein the guide member is also joined to the head support base in the joining step of the head support base and the whole head base.   A droplet discharge head according to any one of claims 1 to 12, or a droplet discharge head manufactured by the method of manufacturing a droplet discharge head according to any one of claims 13 to 15. A droplet discharge device characterized by comprising:   An image forming apparatus comprising the droplet discharge device according to claim 16.

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