JP6168381B2 - Droplet ejection apparatus, image forming apparatus, and method of manufacturing droplet ejection apparatus - Google Patents

Description

  The present invention relates to a droplet discharge device equipped with a droplet discharge head that discharges liquid from a nozzle hole, an image forming apparatus that forms an image by discharging a recording liquid agent onto a medium from a nozzle hole of the droplet discharge head, and a droplet The present invention relates to a method for manufacturing a discharge device.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a plotter, and a complex machine of these, for example, an ink jet recording apparatus using a liquid droplet discharge head for discharging ink liquid droplets is known. This ink jet recording apparatus means a sheet on which ink droplets are conveyed from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Alternatively, it is discharged onto a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). This ink jet recording apparatus includes a serial type that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, which is a direction orthogonal to the direction in which the paper is transported, and a liquid that does not move. There is a line type using a line type head that discharges droplets to form an image.

  In any type of ink jet recording apparatus, the accuracy of the position where the droplet discharge head is assembled to the base plate (substrate) on the apparatus side has a great influence on the accuracy of the discharge position, and must be high. As a droplet discharge device having a configuration in which a droplet discharge head is assembled to a base plate with high accuracy, a device described in Patent Document 1 is known. In the droplet discharge device of Patent Document 1, a droplet discharge head is supported on a base plate using a sub plate (support member). The sub plate includes a base portion that is fastened with a screw to a flange portion (joining portion) that extends from a part of the outer periphery of the head frame (housing) of the droplet discharge head, and a leg portion that is fastened to the base plate with a screw. Are integrated. The flange portion of the droplet discharge head is fastened to the base portion of the sub plate with a screw, and the droplet discharge head and the sub plate are connected to each other. The position at which the droplet discharge head connected to the sub plate is assembled to the base plate is determined by a positioning plate interposed between the base portion of the sub plate and the base plate. This positioning plate is joined to the base portion of the sub-plate by, for example, an adhesive or laser welding. A positioning pin is provided on one surface of the base plate side member facing the one surface of the positioning plate, and a positioning hole for press-fitting the positioning pin is provided on one surface of the positioning plate. These positioning plates, positioning pins and positioning holes constitute positioning means. The installation position of the positioning pin and the positioning hole is set in advance so that the position is determined at the target relative position between the sub plate and the base plate when the positioning pin is press-fitted into the positioning hole. . Then, by pressing each positioning pin into each positioning hole, the base portion of the sub plate joined to each positioning plate is positioned at a target relative position with respect to the base plate. Thereafter, the legs of the sub-plate are fastened to the base plate with screws.

  However, in the droplet discharge device of Patent Document 1, the material of the housing of the subplate and the droplet discharge head is not specified. The sub-plate is considered to be formed of a metal material so that the sub-plate is not deformed with respect to the fastening force when fastened to the base plate with screws, and the positioning is not affected. The casing of the droplet discharge head is considered to be formed of a resin material in order to realize high productivity and low cost. And the flange part extended from a part of outer periphery of the housing | casing is also formed with the resin material. For this reason, when the metal sub plate and the flange portion of the resin material droplet discharge head are fastened with screws and connected to each other, the flange portion is deformed by the fastening force, and the sub plate and the flange portion are There is a possibility that the position shifts.

  Therefore, it is conceivable to join the sub plate and the flange portion using an adhesive or laser welding instead of fastening the sub plate and the flange portion of the droplet discharge head with screws. In this case, since the linear expansion coefficients are different between the plates that are joined together in the joining of the sub-plate and the flange portion, for example, when the adhesive polymerization heat or the laser welding is used for the joining. There is a possibility that the position difference between the sub plate and the flange portion may occur due to the welding heat. Therefore, it is desirable to make the linear expansion coefficients of the sub-plate and the flange portion equal. However, even if an attempt is made to form a subplate with a metal material equal to the linear expansion coefficient of the resin material on the flange portion, the subplate becomes very expensive because there are few types of metal materials equal to the linear expansion coefficient of the resin material. Even if a resin-molded material is used for the sub-plate, it is necessary to increase the mixing ratio of the glass fiber to the resin in order to increase the rigidity against deformation caused by the fastening force by the screw. As a result, the resin material becomes expensive, and it is necessary to apply an expensive coating on the inner surface of the mold in order to prevent damage to the mold during molding with glass fibers. For these reasons, it is difficult to equalize the linear expansion coefficients of the sub-plate and the flange portion while suppressing the price. Thereby, when joining a subplate and a flange part and connecting, the possibility of the position shift of the relative position of a subplate and a flange part cannot be eliminated. Therefore, the droplet discharge head connected to the sub plate via the flange portion is displaced from the target relative position with respect to the base plate, and the accuracy of the droplet landing position is lowered.

  The present invention has been made in view of the above-described problems, and its purpose is to provide a liquid that can suppress the displacement of the relative position between the droplet discharge head and the substrate at a low cost and can suppress the drop in the accuracy of the landing position of the droplet. To provide a droplet discharge device, a method for manufacturing the droplet discharge device, and an image forming apparatus.

In order to achieve the above object, the invention of claim 1 is configured such that a droplet discharge head having a liquid discharge member for discharging droplets and a support frame member for supporting the liquid discharge member is attached to an array base. in the liquid droplet ejection apparatus, the support frame members, metal plates are attached together, the said metal plates, the positioning plate is joined, the liquid droplet ejection head, said positioning plate The support frame member is made of a resin material, and the metal plate and the positioning plate are made of a metal material having substantially the same linear expansion coefficient . It is characterized by.

In the present invention, the metal plate and the positioning plate are metal materials having substantially the same linear expansion coefficient. For example, a metal plate及 beauty positioning plate be welded heat polymerization heat or laser welding of the adhesive occurs when they are joined together using an adhesive or laser welding is substantially expand like contraction. As a result, the relative position between the metal plate and the positioning plate after joining the positioning plate to the metal plate does not change. Thus, the droplet discharge head will be positioned relative position for the array base is made. Further, the metal plate及 beauty positioning plate by forming a metal material, so no need to apply an expensive coating on the inner surface of the mold to prevent damage to the mold, such as when molding a resin material Become. Accordingly, it is possible to obtain a unique effect that the displacement of the relative position between the droplet discharge head and the array base can be suppressed at a low cost, and the deterioration of the droplet landing position accuracy can be suppressed.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a top view which shows the mode of the droplet discharge head of a staggered arrangement. It is a perspective view which shows the structure of a droplet discharge head. It is a figure which shows the cross section of a droplet discharge head. It is a perspective view which shows the structure by which the droplet discharge head and the positioning plate were joined. It is a perspective view which shows an array base. It is a perspective view which shows the structure which attached the droplet discharge apparatus to the head inclination mechanism. It is a perspective view which shows the structure of a head inclination mechanism. It is a perspective view which shows the conical part with a screw | thread, and the spherical body adhesively joined. It is a perspective view which shows the structure of a droplet discharge apparatus. It is a schematic block diagram of a differential screw. It is a flowchart which shows the manufacturing process of a droplet discharge apparatus. It is sectional drawing of two metal mold | die which insert-molds the support frame member and metal plate in a droplet discharge apparatus. It is a flowchart which shows the adjustment process of a landing position. It is a figure which shows the read test image. It is a block diagram which shows the structure of a positioning plate joining 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 structure of a reference | standard chart. It is a perspective view which shows the mode of the imaging of the nozzle alignment mark by the CCD camera of a positioning plate joining apparatus.

Hereinafter, an embodiment in which the present invention is applied to an image forming apparatus will be described with reference to the accompanying drawings.
As an image forming apparatus of a printer, a facsimile machine, a copying machine, or a composite machine of these, for example, a liquid ejection apparatus including a recording head composed of a liquid ejection head that ejects liquid droplets of a recording liquid is used. Although it is also referred to as “paper”, the material is not limited, and a recording medium (hereinafter referred to as “ink”) is conveyed while conveying a recording medium, a recording medium, a transfer material, recording paper, and the like. Is also attached to a sheet to form an image (recording, printing, printing, and printing are also used synonymously).

  The image forming apparatus means an apparatus for forming an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. The term “not only” means to give an image having a meaning such as a character or a figure to the medium but also to give an image having no meaning such as a pattern to the medium. Further, the liquid is not limited to the recording liquid and ink, and is not particularly limited as long as it is a liquid capable of forming an image. The droplet discharge device means a device that discharges droplets from a droplet discharge head.

Hereinafter, an ink jet copying machine will be described as an embodiment of an image forming apparatus to which the present invention is applied.
FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment. As shown in the figure, an image forming unit 402 in a line type image forming apparatus 401 discharges droplets of each color of yellow (Y), magenta (M), cyan (C), and black (K), for example. Droplet discharge devices 411y, 411m, 411c, and 411k (integrated with four droplet discharge heads of the mold and a sub-tank that supplies ink to the droplet discharge heads) 411 ")). Each droplet discharge device 411 is equipped with a head holder 413 having a nozzle surface on which nozzles for discharging droplets are formed facing downward. As shown in FIG. 2, each droplet discharge device 411 used in this line type image forming apparatus has a liquid on an array base (substrate) 442 that is long in the direction (X-axis direction) orthogonal to the paper feed direction. Drop discharge heads 441a to 441f are arranged in a staggered manner.

  Further, as shown in FIG. 1, maintenance and recovery mechanisms 412y, 412m, 412c and 412k for maintaining and recovering the head performance corresponding to each droplet discharge device 411 ("maintenance and recovery mechanism 412" when colors are not distinguished) Is provided.) Then, during the performance maintenance operation of the head such as the purge process and the wiping process, the respective droplet discharge devices 411 and the maintenance / recovery mechanism 412 are relatively moved. A capping member or the like constituting the maintenance / recovery mechanism 412 is opposed to the nozzle surface of each droplet discharge device 411.

  FIG. 3 is a perspective view showing the configuration of the droplet discharge head. As shown in the figure, a K-color droplet discharge head 441k includes a liquid discharge member 414k, a support frame member (housing) 419k, a metal plate (coupling portion) 420k as an attachment portion, and a liquid supply member (not shown). It consists of and. On the nozzle surface 454k of the liquid ejection member 414k, a nozzle row 415a having a plurality of nozzles 415 formed at equal intervals in the sub-scanning direction (hereinafter referred to as the Y-axis direction) that is the recording paper conveyance direction is arranged in the X-axis direction. Four rows are arranged. In addition, nozzle alignment marks 416k and 417k for use in nozzle position adjustment, which will be described later, are provided at both ends in the Y-axis direction of the nozzle surface 454k in the droplet discharge head 441k in which the nozzle row 415a is formed. The number of nozzles 415 in the droplet discharge head 441k may be appropriately determined according to the model of the ink jet recording apparatus to be mounted, that is, the performance. A metal plate 420k is formed around the support frame member 419k.

  FIG. 4 is a cross-sectional view of the droplet discharge head. The same reference numerals as those in FIG. 3 denote the same components. As shown in FIGS. 4A and 4B, the liquid ejection member 414k is a member formed by joining a nozzle plate, a flow path forming plate, a vibrating member, and a drive forming member in this order. The support frame member 419k is configured between the liquid ejection member 414k and the liquid supply member 423k, and a metal plate 420k is configured around the support frame member 419k. The metal plate 420k and the support frame member 419k are parts manufactured by insert molding described later. Further, the support frame member 419k and the metal plate 420k are made of a material having substantially the same linear expansion coefficient. Specifically, SUS304 is used for the metal plate 420k, and a thermoplastic resin containing glass fiber is used for the support frame member 419k. As shown in FIG. 4B, the positioning plate (positioning means) 443k has a shape in which the center is hollowed so that the droplet discharge head 441k is fitted in the center. After being accurately positioned by nozzle position adjustment described later, it is joined to the droplet discharge head 441k by an adhesive or the like. The metal plate 420k and the positioning plate 443k are laser-welded at a laser welding portion 421k at the right end of the metal plate 420k in the drawing. In this example, joining is performed at two locations on the front side and the back side of the drawing. Further, the joining portion 422k at the left end of the metal plate 420k in the drawing is joined with an adhesive having a low joining strength (for example, silicone). In this example, the joining portion 422k is also joined at two locations on the near side and the far side of the drawing. The other droplet discharge heads 441y, 441m, 441c have the same configuration.

  FIG. 5 is a perspective view showing a configuration in which the droplet discharge head and the positioning plate are joined. As shown in the figure, the droplet discharge head 441k is joined to the positioning plate 443k by two laser welds 421k and two joints 422k. The array positioning pins 448 arranged on the array base 442 as shown in FIG. 6 are inserted into the positioning pin holes 449k of the positioning plate 443k. The droplet discharge head 441k is fixed on the array base 442 by mounting screws 446k. Here, as shown in FIG. 6 which is a perspective view showing the configuration of the array base 442, the array base 442 has six insertion holes 462a to 462f (not distinguishing colors) into which the droplet discharge heads 441a to 441f are respectively inserted. (Sometimes referred to as “insertion holes 462”). Two array positioning pins 448 are arranged around each insertion hole 462. The droplet discharge head 441k is fixed by an attachment screw 446k by inserting a fixed positioning plate 443k or an array positioning pin hole 449 provided in the fixing plate 444. In addition, a recess 450k is provided inside the longitudinal edge portions of the support frame member 419k and the metal plate 420k. The recess 450k can prevent the screw head of the mounting screw 446k from interfering with the support frame member 419k, and can reduce the length of the positioning plate 443k in the longitudinal direction. Further, the laser beam irradiated when the metal plate 420k and the positioning plate 443k are laser welded by the laser welding portion 421k is not shielded by the support frame member 419k. For this reason, the length of the support frame member 419k in the longitudinal direction is made shorter than the length of the metal plate 420k in the longitudinal direction, and the extending end of the metal plate 420k is exposed.

Next, an example in which a droplet discharge device in which a droplet discharge head and a positioning plate are joined is attached to a head tilt mechanism will be described.
FIG. 7 is a perspective view showing a configuration in which a droplet discharge device is attached to the head tilt mechanism. FIG. 8 is a perspective view showing the configuration of the head tilting mechanism. As shown in both figures, the conical concave portion 431, the V groove portion 432, the flat surface portion 433, the positioning plate 443, and the fixing plate 444 formed on the surface of the fixing plate 444 among the surfaces where the positioning plate 443 and the fixing plate 444 face each other. Spheres 434 adhesively joined to the threaded cone 435 shown in FIG. 9 at the opposed positions where the conical recess 431, the V groove 432, and the flat surface 433 are in contact with the surface of the positioning plate 443 among the surfaces facing each other. And the tip spherical portion of the first adjustment screw 452 and the tip spherical portion of the second adjustment screw 453 are configured. At this time, the center of the conical recess 431 is arranged on an extension line of the center of the V groove 432 provided on the surface of the positioning plate 443, and a straight line connecting the center of the V groove 432 and the center of the conical recess 431 is a nozzle row of the recording head. It is parallel to the column direction. Thereby, there is a difference in linear expansion coefficient between the droplet discharge head 441 and the positioning plate 443, and even if a difference in elongation occurs due to thermal expansion, it can escape in the direction of the V-groove, and stress that causes deformation concentrates. There is nothing. As a result, high position reproduction accuracy can be ensured even when there is a temperature change.

  In this way, the head tilting mechanism 456 of the positioning plate is pressed by the two stepped screws 445 and the coil spring 447 which are pressing means. As a result, the conical concave portion 431, the V groove portion 432, and the flat surface portion 433 of the fixing plate 444, and the spherical body 434 disposed on the positioning plate 443 and the tip spherical portions of the two adjusting screws 452, 453 are fixed in contact with each other. In this state, the protrusion amounts of the tip sphere portions of the first adjustment screw 452 and the second adjustment screw 453 are adjusted so that the upper surface of the positioning plate 443 and the lower surface of the fixing plate 444 are parallel to each other. After inserting the droplet discharge head 441 into the insertion hole 462 in FIG. 8, the position and inclination of the nozzle of the droplet discharge head 441 with respect to the positioning plate 443 are adjusted as shown in FIG. Thereafter, as described above, laser bonding at the two laser welding portions 421 and adhesive bonding at the two bonding portions 422 are performed. The array positioning pins 448 arranged on the array base 442 are inserted into the positioning pin holes 449 of the fixing plate 444, and are fixed by the mounting screws 446 as shown in FIG.

  FIG. 10 is a perspective view showing the configuration of the droplet discharge device. As shown in the figure, in the droplet discharge device 411k, each droplet discharge head 441 is attached to an array base 442 that supports the droplet discharge heads 441a to 441f. And it has positioning plates 443a, 443b, 443c, 443d, 443e, 443f for positioning the droplet discharge head 441. The plurality of droplet discharge heads 441a to 441f have a plurality of insertion holes into which the droplet discharge heads 441 are inserted into the array base 442 that is long in the direction (X-axis direction) orthogonal to the paper feed direction indicated by the arrows in the drawing. Two insertion hole rows are arranged in the Y-axis direction (paper feeding direction) in which (not shown) are arranged at equal intervals in the X-axis direction (direction perpendicular to the paper feeding direction). Two array positioning pins 448 per head are arranged on the array base 442 around each insertion hole. Then, the positioning plates 443a to 443f joined to the droplet discharge heads 441a to 441f are aligned with the positioning holes of the fixed plates 444a to 444f which are positioned and integrated. Thereafter, each fixing plate 444 a to 444 f is fixed to the array base 442 by two mounting screws 446. Thereby, each of the droplet discharge heads 441a to 441f is positioned and fixed to the array base 442. The fixing plates 444a to 444f integrated with the respective droplet discharge heads 441a to 441f are configured to be detachable from the array base 442. For this reason, at the time of replacement due to the life or failure of the droplet discharge head, it is possible to replace it with a new droplet discharge head by removing the two mounting screws 446 that fix only the failed droplet discharge head.

  The print position of the droplet discharge head disposed on the array base can be adjusted using the head tilt mechanism 456 described above, and using the first adjustment screw 452 if the position in the X direction is to be corrected. Further, when it is desired to adjust the position in the Y direction, the position can be adjusted using the second adjustment screw 453. That is, the landing position can be changed in the X direction by causing the droplet discharge head to rotate around the Y axis by pushing the first adjusting screw 452 and changing the discharge direction of the droplet discharge head 441. Next, by pushing the second adjustment screw 453, the droplet discharge head 441 rotates around the X axis, and the landing position can be changed in the Y direction by changing the discharge direction of the droplet discharge head 441. .

  FIG. 11 is a schematic configuration diagram of the differential screw. As shown in the figure, the differential screw 455 includes a cylindrical outer screw 455a, a cylindrical inner screw 455b having a slightly smaller pitch than the outer screw 455a, a drive shaft 455c, and the like. The outer screw 455a has a male screw formed on the outer periphery and a female screw formed on the inner periphery. Then, it is screwed into the screw hole 455g of the outer cylinder 455f. A male screw having a slightly smaller pitch than the male screw formed on the outer periphery of the outer screw 455a is formed on the outer periphery of the inner screw 455b, and is screwed into the outer screw 455a. The drive shaft 455c passes through the inner screw 455b, and the tip of the inner screw 455b (the side opposite to the operation side) is fastened to the drive shaft 455c by a clamp 455d. The inner screw 455b cannot be rotated by the rotation stopper 455e. When the operating portion 455a-1 of the external screw 455a is operated to rotate the external screw 455a, the internal screw 455b is pushed down together with the drive shaft 455c. The distal end shape of the drive shaft 455c is R-shaped and is in contact with the V-groove portion 432 and the flat portion 433. As a result, the positioning plate 443 is pushed up. Thereby, the inclination angle of the positioning plate 443 can be changed. The amount of movement of the drive shaft 455c is, for example, M5 for a male screw formed on the outer periphery of the outer screw 455a, a pitch of 0.5 [mm], and M2.5 for the male screw formed on the outer peripheral surface of the inner screw 455b. Is 0.45 [mm]. When the outer screw 455a is rotated once, the inner screw 455b moves in the Z axis direction of 0.05 [mm] together with the drive shaft 455c. Thus, by using the differential screw 455 as the first adjustment screw 452 and the second adjustment screw 453, the tip sphere portion of the first adjustment screw 452 is in contact with the V-groove portion 432, so that the positioning plate 443 Tilt. Similarly, since the tip sphere portion of the second adjustment screw 453 is in contact with the flat portion 433, the positioning plate 443 is inclined. This makes it possible to finely adjust the tilt angle of the droplet discharge head.

  FIG. 12 is a flowchart showing a manufacturing process of the droplet discharge device. In the figure, first, a first joining step for joining the support frame member 419 and the liquid discharge member is performed (step S101). Next, an alignment process for positioning the joined body joined in the first joining process and the positioning plate 443 is performed (step S102). And the 2nd joining process of irradiating a laser beam and welding-welding between the metal plate 420 insert-molded simultaneously with the support frame member 419 and the positioning plate 443 which consists of metal members is performed (step S103). A droplet discharge apparatus is manufactured by performing the above steps.

Next, insert molding will be described.
FIG. 13 is a cross-sectional view of two molds for insert-molding a support frame member and a metal plate in the droplet discharge head. After the metal plate 420 is inserted in advance into the mold 457 and the mold is closed, the resin filling is started from the gate 459. In accordance with the shapes of the mold 457 and the mold 458, an insert-molded part in which the metal plate 420 is integrated with the shape of the support frame member 419 is manufactured.

Here, a procedure for replacing the droplet discharge head will be described.
First, remove the two mounting screws to which the failed droplet ejection head is fixed, move the failed droplet ejection head away from the droplet landing surface, and remove the failed droplet ejection head from the array base. Remove from. Next, a new droplet discharge head to which the positioning plate is bonded is attached to the array base. In this case, as described above, as described above, the array base has an insertion hole into which the droplet discharge head is inserted. Two array positioning pins are arranged around the insertion hole. The droplet discharge head is fixed by a fixing screw by inserting a fixed positioning plate or an array positioning pin hole provided in the fixing plate. At this time, one of the array positioning holes is a long hole and can be easily inserted even if the tolerance of the distance between the array positioning pins is loosened. Therefore, the position can be easily determined and fixed by the mounting screw. Next, an ink supply tube for supplying ink to the ink supply member of the droplet discharge head is attached. While printing in this state, confirming the landing position of the printed droplet, adjust the landing position of the droplet discharge head in the X-axis direction using the first adjustment screw, and adjust the landing position of the droplet discharge head. Use the screw to adjust the landing position in the Y-axis direction. This completes the replacement operation of the droplet discharge head.

  Next, specific landing position adjustment will be described. FIG. 14 is a flowchart showing the landing position adjustment process. First, as described above, after replacing the droplet discharge head, the carriage provided with the droplet discharge device is moved to a position facing the recording paper 5 and stopped (steps S101 to S103). When the carriage stops at a position facing the recording paper 5, the recording paper is conveyed to form a test image as shown in FIG. 15 on the recording paper 5 (step S104). A test image as shown in FIG. 15 is formed by ejecting droplets from all the nozzles once while the carriage is stopped. In FIG. 15, the C droplet discharge head 441c is replaced. When the replaced droplet discharge head 441c is tilted around the Y axis, the droplet discharged from the C color is close to the M color or K It is discharged near the color. As a result, the interval between adjacent colors is shorter or longer than the above-described a1 than the ideal interval (interval a1 between Y color and M color). Further, when the replaced droplet discharge head 441c is tilted around the X axis, the droplets land at positions shifted by b1 in the Y axis direction (sub-scanning direction) with respect to other colors.

  Next, the image forming apparatus displays on the operation display unit or the like that the recording paper 5 on which the test image is formed is set in the image reading unit. The service person sets a test image in the image reading unit and operates a start button (not shown). When the start button is pressed, the image forming apparatus reads a test image (step S105) and grasps the landing position deviation (step S106). For example, the interval between the color (C color in FIG. 15) and the adjacent color (M color or K color in FIG. 15) measured by the replaced droplet discharge head 41c is measured from the read test image. The difference between this interval and the target interval a1 is calculated to grasp the landing position deviation in the X-axis direction (main scanning direction). Further, from the test image, the distances Cy, Cm, and Ck from the landing position of one end in the Y-axis direction (sub-scanning direction) of the color other than the color discharged by the replaced droplet discharge head 441c to the end of the recording paper are measured. The average value is calculated. Next, the distance Cc from the landing position of one end in the Y-axis direction (sub-scanning direction) of the color discharged by the replaced droplet discharge head 441c to the end of the recording paper is measured, and the difference from the above average value is calculated. Then, the landing position deviation in the Y-axis direction (sub-scanning direction) is grasped. The target distance C1 is stored in advance. The distance Cc from the landing position of one end in the Y-axis direction (sub-scanning direction) of the color discharged by the replaced droplet discharge head 441c to the end of the recording paper is compared with the target distance C1, and the Y-axis The landing position deviation in the direction (sub-scanning direction) may be grasped.

Next, the control unit of the image forming apparatus calculates the adjustment amounts of the first adjustment screw 452 and the second adjustment screw 453 based on the grasped landing position deviation and displays them on a display unit (not shown) (step). S107). Then, the service person adjusts the landing position by adjusting the first adjustment screw 452 and the second adjustment screw 453 based on the content displayed on the display unit (not shown). For example, when it is desired to adjust the landing position in the X-axis direction by 5 [μm], the inclination of the droplet discharge head 441 around the Y-axis is adjusted. The distance from the top of the sphere 434 in the X-axis direction to the tip sphere of the first adjustment screw 452 is 50 [mm], and the distance from the nozzle surface of the droplet discharge head 441 to the recording paper is 1 [mm]. In this case, the pushing amount of the differential screw 455 used for the first adjusting screw 452 by the drive shaft 455c is 50 times the deviation amount of the landing position. More specifically, for example, the rotation angle θ around the Y axis of the droplet discharge head 441 necessary for moving the landing position in the X axis direction by 5 [μm] is tan ⁻¹ θ = 5 / (1 × 1000 Therefore, θ = 0.29 °. The adjustment amount for rotating the droplet discharge head 441 about 0.29 ° Y-axis is tan (0.29) × 50 × 1000 = 250 [when the interval of the spheres in the X-axis direction is 50 [mm]. μm]. The differential screw 455 used for the first adjustment screw 452 moves in the Z-axis direction by 50 [μm] when the outer screw 455a is rotated once. In this case, the first adjustment screw 455 A display indicating that the screw 452 is to be rotated five times is displayed. Then, the service person adjusts the landing position by adjusting the first adjustment screw 452 based on the content displayed on the display unit (not shown). When the adjustment is completed, a predetermined operation is performed on the image forming apparatus to notify the image forming apparatus that the adjustment is completed (step S108: YES).

  In the above description, the image forming apparatus includes the image reading unit. However, in an apparatus that does not include the image reading unit as illustrated in FIG. 16, the test image is read by the image reading apparatus outside the image forming apparatus. Then, the read image data may be transmitted to the image forming apparatus. Further, in the image forming apparatus as shown in FIG. 16, a test image formed by disposing an image reading means such as a CCD camera on the downstream side in the recording paper conveyance direction from the carriage is captured by the CCD camera. Test image data may be obtained. In this case, a reference line is drawn in advance on the lens of the CCD camera, etc., and the reference line is imaged together with the test image on the recording paper, the amount of deviation of the landing position from the reference line is calculated, and the deviation of the landing position is calculated. You may make it grasp.

Next, a positioning plate joining apparatus for joining the positioning plate and the droplet discharge head will be described.
FIG. 16 is a block diagram showing the configuration of the positioning plate joining apparatus. A positioning plate joining apparatus 300 shown in the figure is an apparatus that joins the positioning plate by aligning the position of the nozzle row of the droplet discharge head. The positioning plate joining apparatus 300 mainly includes a holding unit 334 for holding the positioning plate, a stage unit 333, a stage control unit 340, and an image processing unit 350.

  A holding portion 334 for holding the positioning plate 443 has the same configuration as the support plate 442. Then, the positioning plate 443 is placed on the three spheres provided at predetermined positions on the base of the holding portion 334 so as to be aligned with the conical concave portion, the V-shaped groove portion, and the flat portion on the bottom surface. . Then, it is pressurized from above by an upper urging means (not shown) and fixed to the holding portion 334.

  The stage unit 333 includes an arm unit 335 that holds the droplet discharge head 441 and a stage moving unit 337 that moves the arm unit 335. The stage moving unit 337 includes a Y-axis stage 331 that can move the arm unit 335 in the nozzle row direction (Y-axis direction), an X-axis stage 332 that moves in a direction orthogonal to the nozzle row (X-axis direction), and an XY plane. The rotating stage 336 is configured to rotate. Thereby, the nozzle position of the droplet discharge head 441 can be moved in accordance with predetermined positions in the Y-axis direction, the X-axis direction, and the θ rotation direction.

  The stage control unit 340 includes a stage position detection unit 341, a target position calculation unit 342, a stage drive unit 343, a stage drive control unit 344, an adhesive application unit 345, and an ideal position measurement unit 346. The stage position detector 341 detects the position of the stage. The stage drive control unit 344 controls the stage drive unit 343. The adhesive application unit 345 fills the adhesive between the metal plate 20 (see FIG. 4) of the droplet discharge head 441 and the positioning plate 443. The target position calculation unit 342 includes the coordinates (xa, ya) of the ideal position a and the center coordinates (XA, YA) of the nozzle alignment mark 253 shown in FIG. 17 registered in the ideal position registration unit 358 of the image processing unit 350 and the ideal. The difference between the coordinates (xb, yb) of the position b and the center coordinates (XB, YB) of the nozzle alignment mark 252 is calculated. Then, the distances from the nozzle alignment marks 252 and 253 to the ideal positions a and b are calculated. In addition, the stage position detection unit 341, the target position calculation unit 342, the stage drive unit 343, the stage drive control unit 344, the adhesive application unit 345, and the ideal position measurement unit 346 of the stage control unit 340 can be operated by the operation unit 347. ing.

  The image processing unit 350 includes CCD cameras 351 and 352, coaxial incident illumination units 353 and 354, a monitor 355, an operation unit 356, a nozzle alignment mark measurement unit 357, and an ideal position registration unit 358. The CCD cameras 351 and 352 image the vicinity of the nozzle alignment marks 252 and 253 provided on the droplet discharge head 441 as shown in FIG. The coaxial incident illumination units 353 and 354 illuminate the nozzle alignment marks 252 and 253 and the vicinity thereof. The CCD cameras 351 and 352 of the present embodiment acquire images by photographing the vicinity of the nozzle alignment marks 252 and 253 from a direction perpendicular to the head surface on which the nozzle alignment marks 252 and 253 are formed. For this reason, CCD cameras 351 and 352 having a measurement field of view of horizontal 1.2 mm × vertical 0.9 mm and subject depth of ± 110 [μm] are used.

  The monitor 355 displays nozzle alignment marks 252, 253 and the like imaged by the CCD cameras 351, 352. The nozzle alignment mark measurement unit 357 performs a series of image processing based on image data in the vicinity of the nozzle alignment marks 252 and 253 photographed by the CCD cameras 351 and 352 and detects the positions of the nozzle alignment marks 252 and 253. 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 252 and 253 are specified.

  In the present embodiment, as shown in FIG. 17, the center coordinates (XA, YA) of the nozzle alignment mark 253 and the center coordinates (XB, YB) of the nozzle alignment mark 252 are measured, and the data is sent to the nozzle alignment mark measurement unit 357. Output. These series of processes are configured from an image processing system that is activated by incorporating a part of dedicated hardware and software into a general-purpose information device. In the present embodiment, an optical image portion having a pixel resolution of 1.6 [μm] / pixel is provided, and the measurement accuracy is 0.5 [μm] by gray processing which is a general software processing.

  The ideal position registration unit 358 acquires and registers the ideal position by being measured by the ideal position measurement unit 346 based on the reference chart 500 in which the ideal position shown in FIG. 18 is recorded. The reference chart 500 is configured by attaching a glass plate 501 on which ideal positions a and b are recorded as shown in FIG. This reference chart 500 is accurately made with micron accuracy with ideal dimensions at the positions of the nozzle alignment marks 252 and 253 of the droplet discharge head 441. A glass plate 501 on which the ideal position a and the ideal position b are accurately recorded with micron accuracy is bonded to the base material 502.

  For obtaining the ideal position, the reference chart 500 is first attached to the positioning plate joining apparatus 300 of FIG. Based on the signal from the target position calculation unit 345 of the stage control unit 340, the ideal positions a and b are imaged by the CCD cameras 351 and 352. Next, the ideal positions a and b are measured by the ideal position measurement unit 346. Then, the ideal position measurement unit 346 transfers this measurement result to the ideal position registration unit 358 and registers this measurement result. A reference chart 400 of FIG. 18 is attached instead of the positioning plate 443.

  Next, a process of bonding the droplet discharge head 441 of the positioning plate bonding apparatus 300 to the positioning plate 443 will be described. The droplet discharge head 441 is joined to the positioning plate 443 by executing a program stored in a storage unit (not shown) provided in the image processing unit 350 in the image processing unit 350. First, when the power of the positioning plate joining apparatus 300 is turned on, the origin is returned and the origin of the positioning plate joining apparatus 300 is determined. Next, the registered ideal positions a and b are acquired. First, in the holding portion, the head tilt mechanism 456 configured between the positioning plate 443 and the fixing plate 444 is fixed to the two positioning pins provided in the holding portion with the positioning holes 449 and fixed using the mounting screws 446. To do. At this time, in the head tilt mechanism 456, each of the conical portions 431 and 435 is used by using the first adjustment screw 452 and the second adjustment screw 453 so that the bottom surface of the fixing plate 444 and the top surface of the positioning plate 443 are parallel to each other. And an interval determined by the contact of the sphere 434. Next, the droplet discharge head 441 is disposed on the engaging portion (not shown) in alignment with the insertion hole 462, and the positioning plate 443 and the metal plate 420 are disposed at a predetermined interval. At this stage, the adhesive application unit 345 is used to apply an adhesive having a relatively low bonding strength. Then, the support frame member 419 of the droplet discharge head 441 is held by the arm portion 335, and the arm portion 335 is moved in a direction perpendicular to the base of the holding portion 334 (Z-axis direction) or the like, so that the nozzle hole 251a is formed. Temporarily fixed to the positioning plate 443 in a state of being positioned below.

  Next, position adjustment by the arm portion 335 holding the temporarily fixed droplet discharge head 441 is started. As described above, the position of the droplet discharge head 441 is adjusted by moving in the front-rear and left-right rotation directions (X-axis direction and Y-axis direction) while being pressed against the positioning plate 443 by an unillustrated biasing means. Done. Next, as shown in FIG. 19, the vicinity of the nozzle alignment marks 252 and 253 is simultaneously imaged by the CCD cameras 351 and 352.

  Next, the nozzle alignment mark measurement unit 357 detects the positions of the nozzle alignment marks 252 and 253. At this time, the optimal illumination of the coaxial epi-illumination units 353 and 354 is adjusted from the average density calculation of the image, and the optimal binarization is determined. From conditions such as area value, width, height, and circularity The nozzle alignment marks 252 and 253 used as the position reference are specified. Since the nozzle alignment marks 252 and 253 are made of a material that reflects light, the nozzle alignment marks 252 and 253 can be easily identified. Next, based on the difference between the detected position data of the coordinates of the nozzle alignment marks 252 and 253 and the position data of the coordinates of the ideal positions a and b acquired in advance before the droplet discharge head 441 is assembled. Thus, the movement distances of the nozzle alignment marks 252 and 253 to the ideal positions a and b are calculated. Next, the stage drive controller 343 in FIG. 16 moves the droplet discharge head 441 in the X-axis direction and the Y-axis direction so that the ideal positions a and b coincide with the detected nozzle alignment marks 252 and 253. Or rotate in the θ rotation direction. This adjusts the position. In this way, the position adjustment is performed so that the two ideal positions a and b and the nozzle alignment marks 252 and 253 are matched. As a result, with reference to the nozzle alignment marks 252 and 253 provided at both ends in the Y-axis direction of the droplet discharge head 41, the nozzle row of the droplet discharge head is aligned with the apex of the conical recess of the positioning plate 443 and the V-shaped groove portion. The droplet discharge head 441 can be positioned on the positioning plate 443 with high accuracy so as to be parallel to the line connecting the ridge lines. When the position adjustment is completed, a laser is irradiated from a laser irradiator (not shown), and the metal plate 420 and the positioning plate 443 of the droplet discharge head 441 are laser-bonded.

  As shown in FIG. 2, the droplet discharge device 411 includes three droplet discharge heads 441 arranged in a line in the X-axis direction and three droplet discharge heads 441 arranged alternately in the front line in one color. It is a group that performs image formation. Four such sets are arranged in the Y-axis direction (recording conveyance direction). Also in this droplet discharge device 411, each array base 442 is provided with an array positioning pin for each droplet discharge head, so that it is aligned with the positioning hole 449 of each droplet discharge head. Thereby, the droplet discharge head is positioned and fixed on the array base in the X-axis direction, the Y-axis direction, and the Z-axis direction. After the droplet discharge head 441 is attached to the support plate member 419, a test image is formed on the recording paper, and the image is read externally or by an image reading device built in the device. Thereafter, the amount of deviation of the landing position from the ideal position is grasped, and the adjustment amount of the first adjustment screw 452 and the second adjustment screw 453 by the differential screw 455 is calculated and displayed. Then, based on the displayed adjustment amount, the differential screw 455 of the first adjustment screw 452 and the second adjustment screw 453 is operated to adjust the landing position to the target landing position.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect 1)
A metal plate is integrally attached to the support frame member, a positioning plate is joined to the metal plate, and the droplet discharge head is attached to the array base via the positioning plate. The support frame member is made of a resin material, and the metal plate and the positioning plate are made of a metal material having substantially the same linear expansion coefficient.
According to this, as described in the above embodiment, the positioning plate 443 is joined to the metal plate 420 attached integrally with the support frame member 419 of the droplet discharge head. The positioning plate 443 is positioned relative to the array base 442 and fastened to the array base 442. When the positioning plate 443 is joined to the metal plate 420 in the joined body, for example, polymerization heat of an adhesive or welding joining heat of laser welding is generated. Or the heat | fever accompanying an apparatus drive generate | occur | produces. The metal plate 420 and the positioning plate 443 may be deformed by these heats. However, since the metal plate 420 and the positioning plate 443 are formed of metal materials having substantially the same linear expansion coefficient, the metal plate 420 and the positioning plate 443 expand and deform in substantially the same manner. Thereafter, the polymerization heat of the adhesive or the welding heat of the adhesive disappears, and the metal plate 420 and the positioning plate 443 contract in substantially the same manner and return to their original positions. As a result, the relative position between the metal plate 420 and the positioning plate 443 after the positioning plate 443 is joined to the metal plate 420 does not change. This does not affect the positioning of the relative position between the support frame member 419 and the array base 442 of the droplet discharge head. Further, by forming the metal plate 420 and the positioning plate 443 from a metal material, it is not necessary to apply an expensive coating to the inner surface of the mold in order to prevent the mold from being damaged as in the case of molding a resin material. . Therefore, it is possible to suppress the displacement of the relative position between the droplet discharge head and the base array at low cost, and it is possible to suppress the deterioration of the droplet landing position accuracy.
(Aspect 2)
In (Aspect 1), a plurality of droplet discharge heads are arranged and positioned and supported by the array base. According to this, as described in the above embodiment, when a plurality of droplet discharge heads are arranged to form a high-quality image, each droplet discharge head can be positioned with high accuracy. Image formation with high image quality can be performed.
(Aspect 3)
(Embodiment 1) or (Embodiment 2) is provided with the droplet discharge device, and an image is formed by discharging droplets onto a recording medium.
According to this, as described in the above embodiment, even after replacing the droplet discharge head, the droplet can be landed on the target position, and a high-quality image can be obtained over time.
(Aspect 4)
In (Aspect 3), an image reading unit that reads an image formed on the recording medium is provided, a test image is formed on the recording medium, the test image formed on the recording medium is read by the image reading unit, and the liquid to the recording medium is read. It has a correction means for detecting a deviation of the landing position of the droplet and correcting the deviation of the landing position based on the detection result. According to this, as described in the above embodiment, the image reading means for reading the image formed on the recording paper as the recording medium is provided. Then, a test image is formed on the recording paper, the test image formed on the recording paper is read by the image reading means, and the deviation of the landing position of the droplet on the recording paper is detected. Based on the detection result, the deviation of the landing position is corrected by the correcting means. Thereby, the shift | offset | difference of a landing position can be adjusted with high precision.
(Aspect 5)
Including a step of insert-molding the support frame member and the metal plate, and a step of welding and joining the metal plate and the positioning plate with a laser beam. The support frame member is formed of a resin material and is positioned with the metal plate. The plates are made of metal materials having substantially the same linear expansion coefficient.
According to this, as described in the above embodiment, the positioning plate 443 is joined to the metal plate 420 attached integrally with the support frame member 419 of the droplet discharge head. The positioning plate 443 is positioned relative to the array base 442 and fastened to the array base 442. The linear expansion coefficient of the metal material forming the metal plate 420 is substantially the same as the linear expansion coefficient of the metal material of the positioning plate 443. As a result, the metal plate 420 joined to the positioning plate 443 is deformed by the polymerization heat or welding joining heat of the adhesive generated when the metal plate 420 is joined to the positioning plate 443 by, for example, adhesive or laser welding. Deformed together. Then, when the polymerization heat or welding joining heat of the adhesive disappears, the metal plate 420 and the positioning plate 443 are integrally returned to their original positions. Thereby, the relative position of the metal plate 420 and the positioning plate 443 does not change. The droplet discharge head is positioned with high accuracy via the metal plate 420 positioned by the positioning plate 443. Therefore, it is possible to manufacture a droplet discharge device that can suppress deterioration in droplet landing position accuracy.
(Aspect 6)
(Aspect 5), after the step of insert molding, a step of bonding the support frame member and the liquid material discharge member with an adhesive, after the step of adhesively bonded, the positioning of the metal plate and the positioning plate The alignment process to be performed is performed, and the welding process is performed after the alignment process. According to this, as described in the above embodiment, the relative position between the metal plate 420 and the positioning plate 443 does not change. The droplet discharge head is positioned with high accuracy via the metal plate positioned by the positioning plate.
(Aspect 7)
In (Aspect 5) or (Aspect 6), in the step of welding and joining, after one end of the metal plate is welded to the positioning plate by laser light, the other end of the metal plate is joined to the positioning plate with an adhesive. . According to this, as described in the above embodiment, for example, after temporarily bonding using an adhesive having a low bonding strength, adjustment of inclination and the like is performed, positioning is performed, and then laser welding is firmly performed. Join. Thereby, the joining position accuracy can be kept stable with a simple work process.

5 Recording paper 252 Nozzle alignment mark 253 Nozzle alignment mark 300 Plate bonding apparatus 333 Stage unit 334 Holding unit 340 Stage control unit 341 Stage position detection unit 342 Target position calculation unit 343 Stage movement control unit 344 Laser irradiation control unit 345 Adhesive application unit 346 Ideal position measurement unit 347 Operation unit 350 Image processing unit 351 CCD camera 352 CCD camera 353 Coaxial incident illumination unit 354 Coaxial incident illumination unit 355 Monitor 356 Operation unit 357 Nozzle alignment mark measurement unit 358 Ideal position registration unit 363 Ideal position acquisition unit 401 Image forming apparatus 402 Image forming unit 411 Droplet discharge device 412 Maintenance / recovery mechanism 413 Head holder 414 Liquid discharge member 415 Nozzle 416 Nozzle alignment mark 417 Nozzle alignment mark 419 Support frame member 420 Metal plate 421 Laser welded part 422 Joined part 423 Liquid supply member 431 Conical recess 432 V groove part 433 Flat part 434 Sphere 441 Droplet discharge head 442 Array base 443 Positioning plate 444 Fixing plate 445 Stepped screw 447 Coil Spring 448 Array positioning pin 449 Positioning pin hole 450 Recess 452 First adjustment screw 453 Second adjustment screw 454 Nozzle surface 456 Head tilt mechanism 462a to 462f Insertion hole 500 Reference chart 501 Glass plate 502 Base material

JP 2010-194899 A

Claims (7)

In a droplet discharge apparatus configured by attaching a droplet discharge head having a liquid discharge member for discharging droplets and a support frame member for supporting the liquid discharge member to an array base,
A metal plate is integrally attached to the support frame member, a positioning plate is joined to the metal plate, and the droplet discharge head is attached to the array base via the positioning plate. The droplet discharge device is characterized in that the support frame member is formed of a resin material, and the metal plate and the positioning plate are formed of a metal material having substantially the same linear expansion coefficient. apparatus. The droplet discharge device according to claim 1,
A droplet discharge apparatus, wherein a plurality of the droplet discharge heads are arranged and positioned and supported by the array base.   An image forming apparatus comprising the droplet discharge device according to claim 1, wherein the image is formed by discharging the droplet onto a recording medium. The image forming apparatus according to claim 3.
Comprising image reading means for reading an image formed on the recording medium,
A test image is formed on the recording medium, the test image formed on the recording medium is read by the image reading unit, a deviation in the landing position of the droplet on the recording medium is detected, and landing is performed based on the detection result. An image forming apparatus comprising: a correcting unit that corrects a positional shift. In a method for manufacturing a droplet discharge device, in which a droplet discharge head having a liquid discharge member that discharges a droplet and a support frame member that supports the liquid discharge member is attached to an array base.
Insert molding the support frame member and the metal plate;
A step of welding the metal plate and the positioning plate by laser light,
The method of manufacturing a droplet discharge device, wherein the support frame member is made of a resin material, and the metal plate and the positioning plate are made of a metal material having substantially the same linear expansion coefficient. In the manufacturing method of the droplet discharge device according to claim 5,
After the step of molding the insert, a step of bonding the support frame member and the liquid material discharge member with an adhesive, after the step of bonding with the adhesive, the positioning between the metal plate and the positioning plate A method for manufacturing a droplet discharge device, comprising: performing an alignment step, and performing the welding and joining step after the alignment step. In the manufacturing method of the droplet discharge device according to claim 5 or 6,
In the welding and joining step, after one end of the metal plate is welded to the positioning plate by laser light, the other end of the metal plate is joined to the positioning plate with an adhesive. A method for manufacturing a droplet discharge device.

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