JP2011056926A - Liquid discharge head, liquid discharge head unit and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems of complicating head installation work, and of becoming difficult to easily replace a head, when highly accurately arranging a plurality of liquid discharge heads in a head support member. <P>SOLUTION: Three abutting parts 31 formed of an ultraviolet resin are arranged on an outer peripheral surface of a frame member 17 of the liquid discharge head 40, and the five liquid discharge heads 40 are arranged and installed in the head support member 41. An abutting object part (a positioning part) 42 abutting on the abutting parts 31 of the respective heads 40 is formed in the head support member 41, and a pressing means 45 is arranged for pushing the heads 40 against the abutting object part 42. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid discharge head, a liquid discharge head unit, 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, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. As an apparatus, an ink jet recording apparatus or the like is known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto 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). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials, resins and the like are also included. The image is not limited to a flat image, but also includes an image given to a three-dimensionally formed image and a three-dimensional image formed by modeling a three-dimensional solid itself.

  In an image forming apparatus using such a liquid ejection method, the image forming speed greatly depends on the number of nozzles of the recording head, and the number of scans can be reduced by increasing the number of nozzles. Therefore, a plurality of liquid discharge heads are mounted on a head holder (head support member) as a recording head and used to reduce the number of carriage scans and increase the recording speed.

  By the way, when an image is formed in an image forming apparatus using a liquid ejection method, the landing accuracy of droplets ejected from nozzles greatly affects the image quality, and if the landing accuracy of droplets is poor, the image quality is degraded. Therefore, when a plurality of liquid ejection heads are attached, it is necessary to position each head position with high accuracy.

  Therefore, as described above, it is known that a plurality of heads are collectively supported by a holding member, and the holding member is mounted on a carriage so that the position thereof can be adjusted (Patent Document 1).

  Further, a carriage having a head positioning surface that determines the position in the paper feed direction parallel to the scanning axis, a head guide groove perpendicular to the scanning axis, and a mechanism that engages with the head guide groove to suppress movement in the scanning direction. Some include a position adjustment mechanism including a head including a joint portion, front and rear contact surfaces corresponding to the head positioning surface, and a biasing spring that presses the head contact surface against the head positioning surface. (Patent Document 2).

JP 2003-154724 A JP-A-7-314851

  As described above, when a plurality of heads are mounted, if they are directly attached to the carriage, the assembly work of the head with respect to the carriage becomes complicated in order to maintain the position between the nozzles of each head with high accuracy. When one of the heads needs to be replaced due to a failure or the like, the head of the unit to be replaced or the outer portion of the head unit and the position of the nozzle must be formed with high accuracy.

  However, in the configurations disclosed in Patent Documents 1 and 2, the contact surfaces with the support members of the plurality of heads and the positions of the nozzles are not assembled with high precision, and a special detection mechanism is used when the carriage is mounted. There is a problem that the position cannot be easily replaced when replacing the head.

  SUMMARY An advantage of some aspects of the invention is that a liquid ejection head can be positioned with high accuracy on a head support member.

In order to solve the above-described problem, a liquid discharge head according to the present invention includes:
Having an abutting portion to be brought into contact with a positioning portion provided in the head support member;
The contact portion is made of a photocurable resin and is formed on a part of the head.

The liquid discharge head according to the present invention includes:
Having an abutting portion to be brought into contact with a positioning portion provided in the head support member;
The abutting portion is formed on a part of the head by welding a resin material.

  The liquid discharge head unit according to the present invention has a configuration in which a plurality of liquid discharge heads according to the present invention are arranged on a head support member having a positioning portion with which the contact portion of the liquid discharge head contacts.

  An image forming apparatus according to the present invention includes the liquid discharge head according to the present invention or the liquid discharge head unit according to the present invention.

  According to the liquid ejection head of the present invention, the liquid ejection head has an abutting portion that abuts against a positioning portion provided on the head support member, and the abutting portion is made of a photocurable resin and is formed on a part of the head. Since it was set as the structure, it can position to a head support member with high precision.

  The liquid discharge head according to the present invention has a contact portion that contacts the positioning portion provided on the head support member, and the contact portion is formed on a part of the head by welding a resin material. Therefore, the head support member can be positioned with high accuracy.

  The liquid discharge head unit according to the present invention has a configuration in which a plurality of liquid discharge heads according to the present invention are arranged on a head support member having a positioning portion with which the contact portion of the liquid discharge head comes into contact. Positioning with high accuracy enables high-quality image formation and facilitates head replacement.

  According to the image forming apparatus of the present invention, since the liquid discharge head according to the present invention or the liquid discharge head unit according to the present invention is provided, the liquid discharge head is positioned with high accuracy to form a high-quality image. This can be done and the head can be replaced easily.

FIG. 4 is a cross-sectional explanatory view along a direction orthogonal to a nozzle arrangement direction showing an embodiment of a liquid discharge head according to the present invention. It is a cross-sectional explanatory drawing of the direction along a nozzle arrangement direction similarly. It is an external appearance perspective explanatory drawing similarly. It is a plane explanatory view showing an embodiment of a liquid discharge head unit concerning the present invention. 1 is an overall configuration diagram illustrating an example of an image forming apparatus according to the present invention. Similarly it is principal part plane explanatory drawing. It is a whole block diagram which shows the other example of the image forming apparatus which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an embodiment of a liquid discharge head according to the present invention will be described with reference to FIGS. 1 is a cross-sectional explanatory view along a direction perpendicular to the nozzle arrangement direction of the liquid discharge head, FIG. 2 is a cross-sectional explanatory view along the nozzle arrangement direction, and FIG.

  The liquid discharge head includes a flow path plate (flow path member, liquid chamber substrate) 1 formed of a SUS substrate, a vibration plate member 2 bonded to the lower surface of the flow path plate 1, and an upper surface of the flow path plate 1. A pressurized liquid chamber (also referred to as a pressure chamber, a pressure chamber, a flow path, etc.) 6 as an individual flow path that communicates with a nozzle 4 that discharges droplets. A fluid resistance portion 7 also serving as a supply path for supplying ink that is liquid to the pressure liquid chamber 6 is formed, and ink is supplied to the plurality of pressure liquid chambers 6 from a common liquid chamber 8 of a frame member 17 described later. .

  Here, the flow path plate 1 is formed by machining a SUS substrate having a thickness of 50 μm using an acidic etching solution, such as etching or punching, so that each pressurized liquid chamber 6, the fluid resistance portion 7, and a damper chamber described later. Openings such as 20 are formed.

  The diaphragm member 2 is adhesively bonded to the flow path plate 1. The diaphragm member 2 is formed by bonding a second layer 2b made of a SUS substrate or the like to a first layer 2a made of a resin member such as polyimide. For example, the diaphragm member 2 is formed of a nickel metal plate, for example. Things can also be used.

  The nozzle plate 3 forms a large number of nozzles 4 having a diameter of 10 to 30 μm corresponding to the pressurized liquid chambers 6 and is bonded to the flow path substrate 1 with an adhesive. As this nozzle plate 3, what consists of metals, such as stainless steel and nickel, resin, such as a polyimide resin film, silicon | silicone, and those combinations can be used. Further, a water repellent film is formed on the nozzle surface (surface in the ejection direction: ejection surface) by a known method such as a plating film or a water repellent coating in order to ensure water repellency with ink.

  The diaphragm member 2 has a two-layer convex portion of the second layer 2b at the center of the diaphragm portion 2A, which is a deformable region formed by the first layer 2a corresponding to each pressurized liquid chamber 6. 2B is formed, and columnar driving piezoelectric element column elements 12A formed on the piezoelectric member 12 constituting pressure generating means (actuator means) are joined to the convex portions 2B. Further, a columnar non-driving piezoelectric element column 12B formed on the piezoelectric member 12 is joined to the two-layer structure portion corresponding to the partition wall 6A of each pressurized liquid chamber 6.

  These driving piezoelectric element pillars 12A and non-driving piezoelectric element pillars 12B, which serve as support pillars, are formed by dividing the laminated piezoelectric member 12 into slits by half-cut dicing and dividing it into comb teeth. The element column 12B is also a piezoelectric element, but is a mere support in order not to apply a driving voltage. The laminated piezoelectric member 12 is bonded to the base member 13.

  The piezoelectric member 12 includes, for example, a lead zirconate titanate (PZT) piezoelectric layer having a thickness of 10 to 50 μm / layer, and an internal electrode layer made of silver / palladium (AgPd) having a thickness of several μm / layer. The internal electrodes are alternately electrically connected to the individual electrodes and the common electrode which are the end face electrodes (external electrodes) on the end face, and a drive signal is supplied to these electrodes via the FPC cable 16 Like to do.

  In addition, the ink in the pressurized liquid chamber 6 may be pressurized using the displacement in the d33 direction as the piezoelectric direction of the piezoelectric member 12, or the pressurized liquid chamber using the displacement in the d31 direction as the piezoelectric direction of the piezoelectric element 12. It is also possible to employ a configuration in which the ink in the six is pressurized. In the present embodiment, a configuration using displacement in the d33 direction is adopted.

  Further, a frame member 17 formed by injection molding with, for example, epoxy resin or polyphenylene sulfite (PPS) is joined to the periphery of the diaphragm member 2 with an adhesive.

  A common liquid chamber 8 for supplying ink to each pressurized liquid chamber 6 is formed in the frame member 17, and the supply port 9 formed in the diaphragm member 2 from the common liquid chamber 8 and upstream of the fluid resistance portion 7 are formed. Ink is supplied to the pressurized liquid chamber 6 through the formed flow path 10 and the fluid resistance portion 7. The frame member 17 is also formed with an ink supply port 19 for supplying ink to the common liquid chamber 8 from the outside.

  Damper means for absorbing and attenuating pressure fluctuations in the common liquid chamber 8 is provided. This damper means is formed by a thin portion 21 consisting only of the first layer 2 a of the deformable diaphragm member 2 that forms a part of the wall surface of the common liquid chamber 8. By doing so, the pressure fluctuation in the common liquid chamber 8 at the time of discharge can be suppressed, and even when multiple bits are discharged at high speed, it can be stably discharged. The other surface side of the thin portion 21 faces the damper chamber 20.

  In the liquid discharge head configured as described above, for example, when the voltage applied to the drive piezoelectric element column 12A is lowered from the reference potential, the drive piezoelectric element column 12A is contracted, and the diaphragm member 2 is lowered and the pressurized liquid chamber 6 is lowered. As the volume of the ink expands, the ink flows into the pressurized liquid chamber 6, and then the voltage applied to the driving piezoelectric element column 12 </ b> A is increased to extend the driving piezoelectric element column 12 </ b> A in the stacking direction. By deforming in the direction of the nozzle 4 to shrink the volume of the pressurized liquid chamber 6, the ink in the pressurized liquid chamber 6 is pressurized, and ink droplets are ejected (jetted) from the nozzle 4.

  Then, the diaphragm member 2 is restored to the initial position by returning the voltage applied to the drive piezoelectric element column 12A to the reference potential, and the pressurized liquid chamber 6 expands to generate a negative pressure. Ink is filled into the pressurized liquid chamber 6 from the chamber 8. Therefore, after the vibration of the meniscus surface of the nozzle 4 is attenuated and stabilized, the operation proceeds to the next droplet discharge.

  Note that the driving method of the head is not limited to the above example (drawing-pushing), and striking or pushing can be performed depending on the direction of the drive waveform.

  In this liquid discharge head, as shown in FIG. 3, the abutting contact with the positioning portion of the head support member (see the abutting portion (positioning portion) 42 in FIG. 4) on the outer peripheral surface of the frame member 17. The portion 31 is provided at a plurality of locations. The contact portion 31 is formed using an ultraviolet curable resin.

As a method of forming the abutting portion 31, after the nozzle plate 3 and the frame member 17 are fixed as described above, an alignment mark or nozzle hole 4 formed on the nozzle plate 3 is removed from the camera by a positioning device (not shown). (See the image in the direction of the arrow in FIG. 3) and move to a preset position with high accuracy. The positional accuracy after the movement at this time was moved with high accuracy of ± 3 μm. Thereafter, a fixed amount of, for example, 1 mm ³ of ultraviolet curable resin is supplied to the portion where the contact portion 31 is formed. Then, the glass substrate is brought close to the contact portion with a predetermined distance (gap, for example, 100 μm). As a result, the ultraviolet curable resin is sandwiched in the gap between the glass substrate and the frame member 17, and the resin is cured by irradiating ultraviolet rays from the glass substrate side. The liquid discharge head obtained in this way can form the orthogonal shafts 32 and 33 including the three contact portions 31 and the nozzle hole 4 with relatively high accuracy (in this example, 5 μm).

  Here, the contact portion 31 is formed using an ultraviolet curable resin, but the contact portion 31 can also be formed using a resin material such as a thermoplastic resin. In this case, the contact portion can be formed by once melting the resin material using a plate with a built-in heater instead of the glass substrate and then lowering the temperature.

  That is, if the contact portion 31 is provided integrally with the frame member 17 as in the prior art, the nozzle 4 (or the nozzle plate 3) that must be aligned due to variations during assembly of the liquid ejection head. And the relative position of the contact portion 31 vary. In such a configuration, when positioning the head indicating member such as a carriage after all, it is necessary to adjust the nozzle position using a camera or the like, and the head replacement is not easy.

  However, with the configuration of the present embodiment, the contact portion 32 can be formed after the liquid discharge head is completed, so that the positional relationship between the positioning portion 32 and the nozzle 4 (or nozzle plate 3) is positioned with extremely high accuracy. Can do. That is, the position of the contact portion and the nozzle can be formed with high accuracy, and furthermore, the contact portion can be made of an inexpensive resin, so that an increase in the cost of the head due to the provision of the contact portion can be suppressed. it can. Furthermore, since an ultraviolet curable resin is used, there is no temperature change when the contact portion is formed, and the nozzle position does not shift due to thermal expansion.

  Further, the liquid ejecting head has a contact portion that contacts a positioning portion provided in the head support member, and the contact portion is formed on a part of the head by welding a resin material. Since the contact portion 32 can be formed after completion, the head support member can be positioned with high accuracy. That is, the position of the contact portion and the nozzle can be formed with high accuracy, and furthermore, the contact portion can be made of an inexpensive resin, so that an increase in the cost of the head due to the provision of the contact portion can be suppressed. it can.

  In the above embodiment, the actuator means is described as an example of a piezoelectric actuator, and the same can be applied to a liquid discharge head using another actuator such as a thermal actuator or an electrostatic actuator as pressure generating means.

  In addition, a tank integrated head (head integrated liquid cartridge) in which a head portion including the liquid discharge head of the above embodiment and an ink tank that supplies ink to the head portion are integrated can be configured.

Next, an embodiment of a liquid discharge head unit according to the present invention will be described with reference to FIG. FIG. 4 is an explanatory plan view of the head unit.
This liquid discharge head unit has a module configuration in which a plurality (here, five) of liquid discharge heads 40 according to the above-described embodiment are arranged in a staggered manner on the head support member 41. The head support member 41 is formed with a contacted portion (positioning portion) 42 with which the contact portion 31 of each head 40 contacts. The abutted portion 42 is processed with high accuracy, and the positional accuracy is set to 5 μm, for example. The head support member 41 is provided with pressing means, for example, a spring 45, for pressing the head 40 against the contacted portion 42.

  The liquid discharge head unit as a module configured in this way can accurately position the relative positions of the nozzles of the plurality of heads 40 without any special adjustment, and easily replace the head 40 that has been replaced due to a discharge abnormality or the like. Can be exchanged.

Next, an example of the image forming apparatus according to the present invention including the liquid discharge head according to the present invention will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram for explaining the overall configuration of the mechanism portion of the apparatus, and FIG. 6 is a plan view for explaining a main portion of the mechanism portion.
This image forming apparatus is a serial type image forming apparatus, and a carriage 233 is slidably held in a main scanning direction by main and sub guide rods 231 and 232 which are guide members horizontally mounted on 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 plurality of recording heads 234 including the liquid ejection head according to the present invention for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). Nozzle rows composed of nozzles are arranged in the sub-scanning direction orthogonal to the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  Each of the recording heads 234 has two nozzle rows, one of the two nozzle rows of one head 234a is a black (K) droplet, and the other two nozzle rows are cyan (C) liquid. The two nozzle rows of the other head 234b eject magenta (M) droplets, and the other two nozzle rows eject yellow (Y) droplets. Note that, here, a four-color droplet is ejected with a two-head configuration, but each of the four colors can be ejected with one head in a four-nozzle row arrangement per head.

  The carriage 233 is equipped with sub tanks 235a and 235b (referred to as “sub tank 235” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the recording head 234. The sub tank 235 is supplied with ink of each color from the ink cartridge 210 of each color by the supply unit 224 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, a maintenance / recovery mechanism 281 for maintaining and recovering the nozzle state of the recording head 234 is disposed in a non-printing area on one side in the scanning direction of the carriage 233. 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 when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge thickened ink. Yes.

  In addition, in the non-printing area on the other side of the carriage 233 in the scanning direction, idle ejection that receives droplets when performing idle ejection that ejects droplets that do not contribute to recording in order to discharge ink that has been thickened during recording or the like. A 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 this image forming apparatus configured as described above, the sheets 242 are separated and fed one by one from the sheet feeding tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and is conveyed to the conveyor 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.

  As described above, the image forming apparatus includes the liquid discharge head according to the present invention as a recording head, and thus includes the liquid discharge head according to the present invention. Therefore, the liquid discharge head is positioned with high accuracy and has high quality. Image formation can be performed and the head can be easily replaced.

Next, another example of the image forming apparatus according to the present invention including the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 13 is a schematic configuration diagram of the entire mechanism unit of the apparatus.
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 is, for example, four full-line liquids according to the present invention that discharge droplets of each color of black (K), cyan (C), magenta (M), and yellow (Y). The recording heads 411k, 411c, 411m, and 411y (which are referred to as “recording heads 411” when colors are not distinguished) are configured by ejection head units. The head holder 413 is attached to the head.

  In addition, a maintenance / recovery mechanism 412k, 412d, 412m, 412y (referred to as “maintenance / recovery mechanism 412” when colors are not distinguished) for maintaining and recovering the performance of the head corresponding to each recording head 411 is provided. 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.

  Here, the recording head 411 is arranged to eject droplets of each color in the order of black, cyan, magenta, and yellow from the upstream side in the paper conveyance direction, but the arrangement and the number of colors are not limited to this. Further, as the line-type head, one or a plurality of heads provided with a plurality of nozzle rows for discharging droplets of each color at predetermined intervals can be used, and a recording liquid cartridge for supplying a recording liquid to the head and the head. Can be integrated or separated.

  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.

  In addition, the conveyance guide member 423 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).

  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 potential application voltage is applied. When the sheet 403 is fed onto the sheet 433, 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 recording head including the liquid discharge head unit according to the present invention, the liquid discharge head can be positioned with high accuracy and high-quality image formation can be performed. , Head replacement becomes easy.

  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, an image forming apparatus such as a printer / fax / copier multifunction machine. In addition, the present invention can also be applied to an image forming apparatus using a liquid other than the narrowly defined ink or a fixing processing liquid.

DESCRIPTION OF SYMBOLS 1 Flow path plate 2 Diaphragm member 2a 1st layer 2b 2nd layer 2A Vibration area | region 2B Island-shaped convex part 3 Nozzle plate 4 Nozzle 6 Liquid chamber 7 Supply path (fluid resistance part)
8 Common liquid chamber 12 Piezoelectric member 12A Drive piezoelectric element column (drive unit)
12B Non-driving piezoelectric element pillar (post)
13 Base member 17 Frame member 31 Contact portion 40 Liquid discharge head 41 Head support member 42 Contacted portion (positioning portion)
45 Pressing means 233 Carriage 234 Recording head (liquid ejection head)
411 Recording head (liquid ejection head unit)

Claims (4)

Having an abutting portion to be brought into contact with a positioning portion provided in the head support member;
The liquid ejecting head according to claim 1, wherein the contact portion is made of a photocurable resin and is formed on a part of the head. Having an abutting portion to be brought into contact with a positioning portion provided in the head support member;
The liquid discharge head, wherein the contact portion is formed on a part of the head by welding a resin material.   3. A liquid discharge head unit comprising a plurality of liquid discharge heads according to claim 1 arranged on a head support member having a positioning portion with which the contact portion of the liquid discharge head contacts.   An image forming apparatus comprising the liquid discharge head according to claim 1 or 2 or the liquid discharge head unit according to claim 3.

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