JP2012183771A - Liquid ejection head, image forming apparatus and method for manufacturing the liquid ejection head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flatness accuracy of a chamber plate in a polishing process in a liquid ejection head having a flow path unit where a nozzle plate with a plurality of nozzles, the chamber plate with a pressure chamber in communication with the nozzles, and a diaphragm plate for sealing one side surface of the chamber plate are laminated.SOLUTION: An opening 13 for the pressure chamber and a dummy opening 14a for making cutting stock as big as the opening in the polishing process are formed on the chamber plate.

Description

  The present invention relates to a liquid discharge head, an image forming apparatus, and a method for manufacturing a liquid discharge head, and more particularly, to a technique for improving the performance of a liquid discharge head by increasing the finishing accuracy of a chamber plate constituting the liquid discharge head. .

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a plotter, or a complex machine of these, a recording composed of a liquid discharge head (droplet discharge head) that discharges a droplet (for example, ink droplet) of a recording liquid used for image formation. An ink jet recording apparatus or the like is known as an image forming apparatus using a head. This liquid discharge recording type image forming apparatus means that ink droplets from an inkjet head are transported on paper (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected to 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). A serial type image forming apparatus that forms an image by ejecting droplets while the inkjet head moves in the main scanning direction, and a line type head that forms images by ejecting droplets without moving the inkjet 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. In addition, the “image” is not limited to a planar one, but includes an image given to a three-dimensionally formed image, and an image formed by three-dimensionally modeling a solid itself.

  As a configuration of the liquid discharge head, there is an example in which a head is configured by attaching a drive source and ink supply parts to a flow path including a nozzle plate, a pressure generation chamber forming plate, and an elastic plate. Here, the pressure generating chamber forming plate is formed by forging a metal. In forging, since deformation and burrs occur after processing, polishing is necessary for finishing. Here, the following techniques exist for polishing the flow path components of the liquid discharge head.

(1) A forging punch is pressed against a metal material to form a forged product, followed by polishing. The polishing process is performed after the polishing jig is matched with the processed shape portion of the forged product and the relative position between the forged product and the polishing jig is determined. By such a method, it is possible to ensure the coalescence of the forged product and the polishing jig and to polish with high finishing accuracy (see, for example, Patent Document 1).

(2) CMP polishing is performed from the back surface (lower surface) of the silicon substrate by a CMP polishing apparatus, and a polishing end point is detected based on a change in polishing resistance due to a filler filled in the groove and the dummy hole, thereby determining the substrate thickness of the silicon substrate. Value. Thereby, since the polishing depth can be controlled to be constant, the substrate thickness dimension can be made constant, and the height accuracy of the pressure chamber formed in the silicon substrate can be obtained (see, for example, Patent Document 2).

(3) A pressure generation chamber forming plate in which groove-like recesses serving as pressure generation chambers are arranged, a metal nozzle plate having a nozzle opening, and a metal that seals the opening surface of the groove-like recess A liquid ejecting head comprising a flow path unit formed by joining a sealing plate on the groove-like recess side of the pressure generating chamber forming plate and a nozzle plate on the opposite side, The pressure generation chamber forming plate is provided with a plurality of minute recesses in a region other than the processed shape portion, which is a region where each groove-like recess or the like of the pressure generation chamber forming plate is formed. For this reason, the difference in residual stress between the region of the processed shape portion and the other region is made as small as possible to correct or prevent distortion deformation of the pressure generating chamber forming plate (for example, Patent Documents) 3).

In the technique (1), it is mentioned that polishing with high finishing accuracy is possible by positioning with a polishing jig. However, there is no mention of variation in plate thickness, and variation in polishing amount between chips is small, but it is considered difficult to adjust for polishing variation in one chip.
In the technique (2), the polishing amount of the silicon substrate is determined by the change in the polishing resistance of the filler, but there is no mention of a method for making the plate material uniform. In the first place, there is no problem if it is a flat silicon substrate, but it is difficult to make the inside of the chip uniform by the forging process described above, and it is difficult to make the plate material uniform.
The technique (3) is a technique for making the deformation amount by forging uniform by using the minute recesses, but does not mention a method for making the plate thickness uniform for the subsequent polishing.

  An object of the present invention is to provide a method for making the plate thickness in a chip uniform by a polishing process, to improve the bonding reliability between components, and to improve the performance of a liquid discharge head.

In order to achieve the object, the present invention has the following configuration.
(1): In the liquid discharge head of the first means of the present invention, a nozzle plate having a plurality of nozzles, a chamber plate having a pressure chamber communicating with the nozzles, and a diaphragm plate for sealing one side of the chamber plate In a liquid discharge head that combines a flow path unit having a configuration in which thin plates are stacked, an ink unit that supplies ink to the flow path unit, and a drive unit that displaces the vibration plate and discharges ink from a nozzle.
The pressure chambers are formed in a row on the chamber plate, and dummy patterns are arranged outside the pressure chambers at both ends in the arrangement direction of the pressure chambers up to the end of the chamber plate, and are formed as the dummy patterns. The opening ratio of the opening was set to be equal to or higher than the opening ratio of the opening formed as the pressure chamber. Here, a flow path unit is configured by fixing a laminated body of three plates, a nozzle plate, a chamber plate, and a diaphragm plate, to a frame. The pressure chamber can be formed by stamping, and the dummy pattern can be formed by SUS half-etching, forging, or blasting. In one embodiment, the opening formed as the pressure chamber is formed as an opening of a gourd-shaped slit 13 that communicates the pressure chamber 10, the restrictor 11, and the individual manifold 12. The opening formed as the dummy pattern can be exemplified by the same size and circular shape in plan view as the slit 13. Alternatively, other shapes are possible. The aperture ratio is larger for the dummy pattern.
(2): In the liquid discharge head of the second means of the present invention, in the liquid discharge head of the first means, the dummy pattern is a pattern having substantially the same shape as the pressure chamber in a planar view, and the pressure chamber And placed on the chamber plate at the same pitch.
(3): In the liquid discharge head according to the third means of the present invention, in the liquid discharge head according to the first or second means, the aperture ratio of the dummy pattern is made larger than the aperture ratio of the pressure chamber.
(4): In the liquid discharge head of the fourth means of the present invention, in any one of the first to third means, the dummy pattern penetrates the chamber plate.
(5): In the liquid discharge head of the fifth means of the present invention, in any one of the first to third liquid discharge heads, the dummy pattern is a concave shape formed in the thickness direction of the chamber plate. It was decided to consist of parts.
(6): In the sixth means of the present invention, the image forming apparatus includes any one of the first to sixth means. The image forming apparatus here is an ink jet type image forming apparatus.
(7): In the liquid discharge head according to the seventh means of the present invention, the step of forming the dummy pressure chamber or the dummy pattern on the chamber plate, and the step of forming the pressure chamber on the chamber plate The flow path unit is subjected to a step of polishing and flattening both surfaces of the chamber plate, and a step of bonding and bonding the nozzle plate to one surface of the chamber plate in the thickness direction and the diaphragm plate to the other surface. The liquid discharge head according to any one of the first to sixth aspects is formed by combining the flow path unit with the drive unit and the ink unit.

In the liquid discharge head according to claim 1, the plate thickness in the chip can be uniformly polished, the bonding reliability between components can be improved, and the performance of the liquid discharge head can be improved.
In the liquid ejection heads according to claims 2 and 4, since the dummy patterns are arranged in the plane view with substantially the same shape and the same pitch as the pressure chambers, the dummy patterns can be formed under processing conditions common to the pressure chambers.
4. The liquid discharge head according to claim 3, wherein the opening ratio of the dummy pattern is larger than the opening ratio of the pressure chamber, so that the amount of shaving during polishing of the dummy pattern portion can be increased. It becomes easy to process the variation of the tendency plate thickness uniformly.
In the liquid discharge head according to the fifth aspect, since the dummy pattern does not penetrate the chamber plate, the rigidity of the chamber plate is not impaired as compared with the configuration in which the dummy pattern penetrates.
In the image forming apparatus according to the sixth aspect, since the high-performance liquid discharge head according to the present invention is used, an image with good image quality can be output.
In the liquid discharge head manufacturing method according to claim 7, the periphery of the pressure chamber can be firmly polished, and the reliability can be improved.

It is an exploded perspective view of a liquid discharge head. It is sectional drawing of a liquid discharge head. It is a cross-sectional enlarged view of a liquid discharge head. It is a top view of a chamber plate. It is the perspective view which illustrated a mode that a chamber plate is grind | polished, (a) shows the state before grinding | polishing, (b) shows the state in process of grinding | polishing, respectively. (A) is a top view of a chamber plate, (b) is A-A 'sectional drawing in (a). (A) is a top view of a chamber plate, (b) is A-A 'sectional drawing in (a). (A) is a top view of a chamber plate, (b) is A-A 'sectional drawing in (a). (A) is a top view of a chamber plate, (b) is A-A 'sectional drawing in (a). 1 is a front view of an image forming apparatus. 1 is a plan view of an image forming apparatus.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

<First embodiment>
[Configuration of liquid discharge head]
1 is an exploded perspective view of the liquid discharge head, FIG. 2 is a cross-sectional view of the liquid discharge head, and FIG. 3 is an enlarged cross-sectional view of the liquid discharge head. The liquid ejection head 1 is roughly divided into a flow path unit 2 having a nozzle for ejecting ink and flowing liquid, a drive unit 3 for generating energy for ejecting ink, and a tank unit 4 for collecting and distributing ink from the main body. Consists of.

  The flow path unit 2 includes a nozzle plate 5 having a plurality of nozzle rows in which the nozzles 9 are arranged in a row, a chamber plate 6 having a pressure chamber 10 communicating with the nozzles 9, and a diaphragm serving as a wall of the pressure chamber 10. The frame 8 includes a diaphragm plate 7 and a common liquid chamber 19 that supplies ink to the pressure chamber 10.

  On the nozzle plate 5, nozzle rows composed of nozzles 9 arranged at a predetermined nozzle pitch are arranged at a predetermined inter-nozzle pitch. Here, the nozzle pitch is 25.4 / 150 mm, and the pitch between nozzle rows is 25.4 / 150 × 5 mm. The nozzle plate 5 is made of stainless steel and the nozzle 9 is formed by press working. The surface of the nozzle plate 5 on the ink ejection side is subjected to water repellent treatment.

  In the chamber plate 6, a pressure chamber 10 is arranged in alignment with the nozzle 9. FIG. 4 shows a plan view thereof. 3 and 4, a restrictor 11 that restricts the ink flowing into the pressure chamber 10 and an individual manifold 12 that connects the restrictor 11 and the common liquid chamber 19 are formed as a slit 13 with a gourd-shaped opening. One of the openings formed at both ends in the lengthwise direction is the pressure chamber 10, the other is the individual manifold 12, and a narrow passage connecting the pressure chamber 10 and the individual manifold 12 is the restrictor 11. The material of the chamber plate 6 is stainless steel, and the slit 13 is formed by pressing as an opening penetrating in the plate thickness direction in which the pressure chamber 10, the restrictor 11, and the individual manifold 12 are integrated.

  Dummy slits 14 are formed in advance from both ends of the row of slits 13 communicating with the nozzles 9 toward both ends in the longitudinal direction of the chamber plate 6. The dummy slits 14 are formed at equal intervals on the outer sides of the slit rows on the same row as the slit rows. An adhesive escape portion 15 is formed in a region other than the slit 13 and the dummy slit 14. A damper escape portion 16 is formed in a region facing the common liquid chamber 19.

  In FIG. 3, the diaphragm plate 7 constitutes a diaphragm 17 that covers the top of the pressure chamber 10. The diaphragm 17 is formed thin, and a thick island 18 is formed at the center. A damper 31 is formed in a region facing the common liquid chamber 19. The material is Ni and it is formed by electroforming.

  In the frame 8, a common liquid chamber 19 for supplying ink to each nozzle row is formed for each row. Further, the nozzle plate 5, the chamber plate 6 and the restrictor plate are held on one end surface side. Moreover, as shown in FIG. 1, it has the opening part 20 which mounts the drive unit 3. As shown in FIG. In the frame 8, a printed circuit board (PCB) 24 that distributes electrical signals to the drive unit 3 is disposed on the opposite surface to which the diaphragm plate 7 is joined. The material of the frame 8 is stainless steel, and it may be formed by cutting or resin injection molding.

  The drive unit 3 includes a piezoelectric element 21 that expands and contracts the pressure chamber 10 via the diaphragm 17, a base 22 that holds the piezoelectric element 21, and a flexible printed circuit board (FPC) 23 that distributes electrical signals to the piezoelectric element 21. And a printed circuit board 24 connected to each flexible printed circuit board 23 and electrically connected to the main body substrate.

  The piezoelectric element 21 is processed into a comb-teeth shape in accordance with the nozzle 9. The piezoelectric elements 21 are arranged in two rows with respect to one base 22. PZT is used as the material of the piezoelectric element 21. As the material of the base 22, SUS430 is used here. The flexible printed board 23 is connected to the piezoelectric element 21. Here, four flexible printed circuit boards 23 are arranged and connected to the printed circuit board 24, respectively. The printed circuit board 24 aggregates the signals of each flexible printed circuit board 23 and is connected to the upper circuit board with a cable.

  The tank unit 4 receives ink from the main tank from the base part 34 via a tube (not shown) and distributes the ink to the pressure chamber 10 via the frame 8. It also has functions such as a damper that suppresses pressure fluctuations and a filter that removes foreign matter.

[Manufacturing process of liquid discharge head]
A manufacturing process of the liquid discharge head will be described.
In the chamber plate 6, slits 13 including the pressure chambers 10 are formed in a row, and a dummy pattern 14 extends to the end of the chamber plate 6 outside the pressure chambers at both ends in the arrangement direction of the slits 13 (pressure chambers 10). Has been placed. The aperture ratio of the opening formed as the dummy pattern 14 is equal to or higher than the aperture ratio of the slit 13 formed as the pressure chamber.

  Thus, pre-processing is performed by the process of forming a dummy pattern corresponding to the dummy pressure chamber or dummy slit 14 on the chamber plate in advance and the process of forming the slit 13 including the pressure chamber on the chamber plate 6. ing.

  When forming the slit 13 in the chamber plate 6, the periphery of the slit 13 is deformed or burrs are generated by press working. In order to flatten the joint surface with the diaphragm plate 7 and the nozzle plate 5 after removing these, first, the both surfaces of the chamber plate 6 are polished and flattened.

  FIG. 5 shows a diagram of the polishing process. As shown in FIG. 5A, a polishing paper 27 is placed on a high-precision flattening jig 26 flattened with high precision, and a chamber plate 6 that is a part to be polished is placed on the chamber plate holding jig 28. In the attached state, as shown by the arrow C in FIG. Here, polishing is performed in a direction orthogonal to the arrow B, which is the direction in which the slit rows are arranged.

  Here, as a comparative example, assuming that there is no dummy slit 14 as shown in FIG. 4, the central slit 13 in the longitudinal direction of the chamber plate 6 is deformed and the cutting area is reduced. So it becomes easy to cut. Therefore, variation occurs in the plate thickness of the slit 13 portion including the pressure chamber.

  In contrast, in this example, as described above, the dummy pattern 14 is disposed outside the pressure chambers at both ends in the longitudinal direction of the chamber plate 6 up to the end of the chamber plate 6 and is formed as the dummy pattern 14. When the opening ratio of the openings is equal to or higher than the opening ratio of the openings formed as the slits 13 including the pressure chambers 10, it is possible to eliminate variations in the thickness of the slit rows in the polishing process.

The flow path unit 2 is configured through a process in which the nozzle plate 5 is bonded to one side of the chamber plate 6 thus flattened and the diaphragm plate 7 is bonded to the other side.
Here, an adhesive is applied to the chamber plate 6 by spraying on both sides, and the plates are bonded and bonded. Since the chamber plate 6 has a uniform thickness in the slit row, the bonding reliability is improved.

  Next, a set (actuator unit) of the piezoelectric element 21, the base 22, and the flexible printed board 23 of the drive unit 3 is joined to the flow path board unit 2. Here, an adhesive is applied and bonded to the piezoelectric element side of the actuator unit. Next, the frame 8 is joined to the flow path substrate unit 2. Here, an adhesive is applied to the frame 8 and joined. Next, the printed circuit board 24 is bonded to the frame 8, and the flexible printed circuit board 23 is bonded to the printed circuit board 24. Joining is performed by melting the solder applied to the printed circuit board 24 with a heater chip. Next, the tank unit (head tank) 4 is joined. Here, they are joined with screws.

  The liquid discharge head 1 bonded in the above configuration distributes ink from the tank unit 4 to the frame 8 and distributes the ink from the common liquid chamber 19 to the nozzle 9 through the individual manifold 12, the restrictor 11, and the pressure chamber 10. The By applying an electrical signal to the drive unit 3 via the flexible printed circuit board 23, the piezoelectric element 21 is expanded and contracted, the volume of the pressure chamber 10 is expanded and contracted, and ink can be ejected from the nozzle 9. .

  As an effect of uniform polishing, variations in droplet velocity and droplet weight between nozzle rows or nozzle rows are reduced, and highly accurate droplet ejection can be performed.

<Second embodiment>
A second embodiment will be described. FIGS. 6A and 6B show the configuration. Here, the dummy slits 14a, which is a kind of dummy pattern formed on the chamber plate 6, are formed at a uniform depth on both sides of the plate with concave portions that do not penetrate the plate thickness of the chamber plate 6. When the dummy slits 14 are provided up to the outer periphery of the head as shown in FIG. 4, the penetrating area is increased and the rigidity of the chamber plate is lowered. However, the rigidity of the chamber plate 6 is increased by adopting a configuration that does not penetrate like the dummy slit 14a, and the discharge characteristics (crosstalk) are improved by the deformation due to handling and the improved rigidity. Here, for example, the dummy slit 14a is formed by machining. The aperture ratio of the dummy pattern portion is larger than that of the slit portion. The slit portion formed by press working or the like is in a state where it can be easily cut off. Here, by making the dummy pattern part easier to cut than the slit part, the plate thickness of the slit part can be formed uniformly. In this case, since the opening ratio of the dummy pattern 14 is larger, the portion of the dummy slit 14a is easily cut and the plate thickness is reduced. However, the plate thickness of the slit portion through which the ink flows is uniform and can be completely sealed by adhesive bonding. Therefore, the thickness variation of the dummy pattern 14a is not a big problem. This aperture ratio is common to the following examples.

<Third embodiment>
A third embodiment will be described. This will be described with reference to FIGS. A dummy slit 14a, which is a kind of dummy pattern formed in the chamber plate 6, is formed by half etching, and the slit 13 is formed by pressing. By forming the dummy slit 14a by half etching, the dummy slit can be formed easily and at low cost.

Further, the dummy slit 14a may be formed by forging. The dummy slit 14a is a concave portion that does not penetrate the plate thickness of the chamber plate 6 and is formed at an equal depth on both sides of the plate. By processing the slit and the dummy slit 14a using the same press machine, the slit 13 and the dummy slit The interval of 14a can be made uniform with the interval of the slit 13, and the thickness variation due to polishing can be further reduced.

  Furthermore, the dummy slit 14a may be formed by blasting. The dummy slit 14a is a concave portion that does not penetrate the plate thickness of the chamber plate 6 and is formed at an equal depth on both sides of the plate. By blasting, the chamber plate 6 itself can be damaged, such as a rough surface. The periphery of 14a can be more easily polished.

<Fourth embodiment>
A fourth embodiment will be described. This will be described with reference to FIGS. In this example, instead of the dummy slit having the same shape as the slit 13 in the previous examples, a free shape as a kind of dummy pattern formed on the chamber plate 6, for example, a circular dummy pattern 32a, is arranged at both ends of the slit row. ing. Since the shape can be freely formed, the shape may be disposed not only at both ends of the slit row but also as the shape that can be disposed throughout the chamber plate 6. Specifically, the adhesive relief 15 may be formed in the same pattern. The dummy pattern 32 a penetrates the thickness of the chamber plate 6.

<Fifth embodiment>
A fifth embodiment will be described. 8A and 8B show the configuration. The dummy pattern 32b has a circular shape as in the fourth embodiment, but differs in that it does not penetrate the plate thickness. By not penetrating the plate thickness, the rigidity of the chamber plate is increased, and the deformation due to handling and the rigidity are improved, thereby improving the discharge characteristics (crosstalk). Here, for example, the dummy pattern is formed by machining.

  As described above, the dummy pattern 32b may be formed by half etching and the slit 13 may be formed by press working. By forming the dummy pattern 32b by half etching, the dummy pattern can be formed easily and at low cost. . In addition, the dummy pattern 32b may be formed by blasting, and the blasting can damage the chamber plate 6 itself, such as surface roughness, so that the periphery of the dummy pattern can be more easily polished.

<Sixth embodiment>
A sixth embodiment will be described. 9A and 9B show the configuration. The dummy pattern 32c is circular and has a structure that does not penetrate the plate thickness as in the fifth embodiment, but differs in that the cross-sectional shape is such that the opening widens on the joint surface side. As a result, even if a sufficiently large aperture ratio is secured, the rigidity of the chamber plate can be increased more than in the fifth embodiment, and the discharge characteristics (crosstalk) are improved due to deformation due to handling and improved rigidity. it can. Such a shape can be formed by forging using a trapezoidal press die.

<Seventh embodiment>
A seventh embodiment will be described. The bonding procedure is formed by forming a dummy pattern, then processing the slits by pressing, then flattening the chamber plate by polishing, and then bonding the nozzle plate and the diaphragm plate to polish the deformation caused by pressing. It can be flattened. Moreover, it can be made easy to cut by forming the dummy pattern in advance according to the polishing amount.

<Eighth embodiment>
An example in which the liquid ejection head described so far is applied to an image forming apparatus will be described with reference to FIGS.
This image forming apparatus is a serial type image forming apparatus, and a carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. The main scanning motor which does not move is moved and scanned in the carriage main scanning direction via the timing belt.

  The carriage 233 has recording heads 234a and 234b (which are composed of liquid ejection heads according to the present invention for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). When not distinguished, it is referred to as “recording head 234”). A nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward.

Each of the recording heads 234 has two nozzle rows. One nozzle row of the recording head 234a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 234b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets. Note that, here, a two-head configuration is used to eject four-color droplets, but a single recording head configuration having a nozzle array in which a plurality of nozzles that eject four-color droplets are arranged.

  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 feeding unit for feeding the paper 242 stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon roller (feeding) that separates and feeds the paper 242 one by one from the paper stacking unit 241. 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.

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

In addition, in the non-printing area on the other side in the scanning direction of the carriage 233, the liquid that receives liquid droplets when performing idle ejection that ejects liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink recovery unit (empty discharge receiver) 288 that is a recovery container is disposed, and the ink recovery unit 288 includes 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 247 and pressed against the conveying belt 251 by the leading end pressure 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, since the image forming apparatus includes the liquid discharge head according to the present invention as a recording head, the reliability of the head is improved and stable recording can be performed.

  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. For example, the present invention may be applied to an image forming apparatus such as a printer / fax / copier multifunction machine. it can. Further, the present invention can be applied to an image forming apparatus using a liquid other than the narrowly defined ink, a fixing processing liquid, or the like.

DESCRIPTION OF SYMBOLS 1 Liquid discharge head 2 Flow path unit 3 Drive unit 4 Tank unit 5 Nozzle plate 6 Chamber plate 7 Diaphragm plate 8 Frame 9 Nozzle 10 Pressure chamber 11 Restrictor 13 Slit 14, 14a, 14b, 14c Dummy slit 15 (adhesive) escape Part 16 damper escape part 17 diaphragm 18 island part 19 common liquid chamber 20 opening part 21 piezoelectric element 22 base 23 flexible printed circuit board 24 printed circuit board 26 high-precision flattening jig 27 polishing paper 28 chamber plate holding jig 31 damper 32a, 32b, 32c Dummy pattern 34 Base portion 202 Paper feed tray 203 Paper discharge tray 210 Ink cartridge 221A, 221B Side plate 224 Supply unit 231, 232 Guide rod 233 Carriage 234, 234a, 234b Recording head 235,235a, 235b sub-tank 236 supply tube 241 paper loading part (pressure plate)
242 paper 243 half moon roller (paper roller)
244 Separation pad 245 Guide member 246 Counter roller 247 Conveying guide member 248 Holding member 249 Tip pressure roller 251 Conveying belt 252 Conveying roller 253 Tension roller 256 Charging roller 261 Separating claw 262 Discharging roller 263 Discharging roller 271 Duplex unit 272 Manual tray 281 Maintenance / recovery mechanism 282, 282a, 282b Cap member 283 Wiper blade 284 Empty ejection receptacle 288 Ink recovery unit 289 Opening
B, C arrows

JP 2004-82386 A JP 2007-301737 A Japanese Patent No. 3632701

Claims (7)

A flow path unit having a configuration in which a nozzle plate having a plurality of nozzles, a chamber plate having a pressure chamber communicating with the nozzles, a thin plate made of a diaphragm plate for sealing one side of the chamber plate, and the flow path In a liquid discharge head that combines an ink unit that supplies ink to a unit and a drive unit that displaces the diaphragm and discharges ink from nozzles.
The pressure chambers are formed in a row on the chamber plate, and dummy patterns are arranged outside the pressure chambers at both ends in the arrangement direction of the pressure chambers up to the end of the chamber plate, and are formed as the dummy patterns. A liquid discharge head, wherein an opening ratio of the opening is equal to or higher than an opening ratio of the opening formed as the pressure chamber. The liquid ejection head according to claim 1,
The liquid ejection head according to claim 1, wherein the dummy pattern is a pattern having substantially the same shape as the pressure chamber in a planar view, and is disposed on the chamber plate at the same pitch as the pressure chamber. The liquid discharge head according to claim 1 or 2,
The liquid ejection head according to claim 1, wherein the aperture ratio of the dummy pattern is larger than the aperture ratio of the pressure chamber. The liquid discharge head according to any one of claims 1 to 3,
The liquid discharge head according to claim 1, wherein the dummy pattern penetrates the chamber plate. The liquid discharge head according to any one of claims 1 to 3,
The liquid ejection head according to claim 1, wherein the dummy pattern includes a concave portion formed in a thickness direction of the chamber plate.   An image forming apparatus comprising the liquid ejection head according to claim 1.   Forming the dummy pressure chamber or the dummy pattern on the chamber plate, forming the pressure chamber on the chamber plate, and performing a flattening process by polishing both surfaces of the chamber plate. The flow path unit is configured through a step of bonding and bonding the nozzle plate to one side of the chamber plate in the plate thickness direction and the diaphragm plate to the other side, and the drive unit and the ink unit are connected to the flow path unit. A liquid discharge head manufacturing method, comprising the liquid discharge head according to claim 1 in combination.

Images