JP2010179632A - Method for manufacturing inkjet head, inkjet head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high resolution of an inkjet head by utilizing a shearing mode deformation. <P>SOLUTION: A method for manufacturing the inkjet head includes: forming an actuator member in which first and second piezoelectric material substrates placing an intermediate layer therebetween are integrated; forming channel rows consisting of a plurality of ink channels respectively on the first and second piezoelectric material substrates; forming driving electrodes on respective ink channels; forming taking-out electrodes connected with the driving electrodes; joining lid substrates constituting one wall face of respective ink channels and constituting common flow paths communicating with respective ink channels on respective both faces of the actuator member; and joining nozzle plates having nozzle holes at parts corresponding to respective ink channels to the actuator member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has a plurality of parallel ink channels separated by a partition made of a piezoelectric material, and deforms the partition according to a drive voltage to a drive electrode formed on the inner wall of the ink channel, The present invention relates to an ink jet head manufacturing method, an ink jet head, and an image forming apparatus in which ink filled in the ink channel is ejected from a nozzle communicating with the ink channel along with the deformation.

  In general, an ink jet recording apparatus performs recording by ejecting ink droplets from a nozzle of an ink jet head toward a recording medium. The noise during the recording operation is low, the running cost is low, the resolution is high, and the quality is high. Image recording is possible and is widely used in various fields.

  2. Description of the Related Art Conventionally, ink jet heads that use shear mode deformation of a piezoelectric element are known as an ink ejection principle (see, for example, Patent Documents 1 and 2).

  Patent Document 1 describes an ink jet head having a plurality of parallel ink channels separated by a partition made of a piezoelectric material. However, since this ink-jet head has a configuration in which a plurality of ink channels are arranged in a line, the nozzle pitch can be reduced even if the cutting means (such as a dicer) for processing the groove portion serving as the ink channel is improved. However, it is difficult to realize a high-resolution inkjet head.

  On the other hand, Patent Document 2 describes an ink jet head in which a plurality of ink channels are arranged in two rows. According to this ink jet head, a channel row composed of a plurality of ink channels is formed on each of both surfaces of a substrate on which two piezoelectric material substrates are bonded together, and the nozzle pitch compared to the configuration described in Patent Document 1 Can be narrowed.

JP-A-63-252750 JP 2002-11887 A

  However, since the inkjet head described in Patent Document 2 forms a channel row composed of a plurality of ink channels on each piezoelectric material substrate, the piezoelectric material substrates on which the channel rows are formed are bonded to each other. The dispersion at the time of alignment and the dispersion of the adhesive cause the position of the nozzles to vary with respect to each ink channel, the ejection stability is lowered, and it is difficult to realize a high-resolution inkjet head.

  The present invention has been made in view of such circumstances, and provides an inkjet head manufacturing method, an inkjet head, and an image forming apparatus that can realize high resolution of the inkjet head using shear mode deformation. With the goal.

  In order to achieve the above object, an inkjet head manufacturing method according to the present invention includes a plurality of ink channels that are parallel to each other and separated by a partition made of a piezoelectric material, and is formed on an inner wall of the ink channel. According to a driving voltage to the electrode, the partition is deformed, and the ink filled in the ink channel is ejected from the nozzle connected to the ink channel according to the deformation. An actuator member forming step of forming an actuator member in which the first piezoelectric material substrate and the second piezoelectric material substrate are integrated with an intermediate layer interposed therebetween, and after the actuator member forming step, Forming a first channel row composed of a plurality of ink channels on the piezoelectric material substrate of An ink channel forming step of forming a second channel row composed of a plurality of ink channels on the second piezoelectric material substrate, and a drive electrode is formed in each ink channel, and an extraction electrode connected to the drive electrode is formed An electrode forming step, a lid substrate joining step for joining a lid substrate constituting one wall surface of each ink channel and communicating with each ink channel on each of both surfaces of the actuator member, and each ink And a nozzle plate joining step of joining a nozzle plate having a nozzle hole in a portion corresponding to the channel to the actuator member.

  According to the present invention, after the first piezoelectric material substrate and the second piezoelectric material substrate are integrated with the intermediate layer interposed therebetween, a plurality of ink channels are formed on each of the piezoelectric material substrates. In other words, since there is no need to bond the piezoelectric material substrates after forming the ink channels, there is no effect of variations in the alignment of the ink channels or variations in the thickness of the adhesive, and the positional accuracy of the nozzles relative to the ink channels As a result, it is possible to realize a high-resolution inkjet head with high ejection stability.

  In the present invention, each ink channel constituting the first channel row and each ink channel constituting the second channel row are the same with respect to the direction (channel row direction) in which a plurality of inks constituting the channel row are arranged. Each ink channel in one channel row may be arranged at a predetermined pitch (for example, 1/2 pitch) in the channel row direction with respect to each ink channel in the other channel row. Also good. Here, the “pitch” refers to an interval between adjacent ink channels in the same channel row.

  Further, the “lid substrate” may be composed of a single substrate or may be composed of a plurality of substrates.

  According to a second aspect of the present invention, there is provided an ink jet head manufacturing method according to the first aspect, wherein each ink channel constituting the first channel row and each of the second channel row are constituted. The ink channels are alternately arranged so that the ink channels of one channel row do not coincide with the ink channels of the other channel row in the direction in which the plurality of ink channels constituting the channel row are arranged. It is characterized by.

  According to the second aspect of the invention, since the ink channels are arranged in a staggered manner, the nozzle pitch can be narrowed, and the resolution of the inkjet head can be increased.

  A third aspect of the present invention relates to an aspect of the method of manufacturing the ink jet head according to the first or second aspect, wherein the actuator member forming step includes a step of forming an external electrode for polarization, and a piezoelectric material substrate. Comprising a step of polarizing the piezoelectric body constituting the substrate and a step of removing the external electrode after the polarization processing.

  According to the third aspect of the invention, the piezoelectric body can be polarized using the external electrode, and the drive electrodes of the adjacent ink channels are made conductive by removing the external electrode after the polarization process. Can be prevented.

  In order to achieve the above object, an ink jet head according to the present invention (the invention according to claim 4) has a plurality of parallel ink channels separated by a partition made of a piezoelectric material, and the ink Ink jet that deforms the partition according to the drive voltage to the drive electrode formed on the inner wall of the channel, and discharges the ink filled in the ink channel from the nozzle connected to the ink channel in accordance with the deformation. A first channel row comprising a plurality of ink channels in a head, wherein a first piezoelectric material substrate and a second piezoelectric material substrate are integrated with an intermediate layer interposed therebetween. And a second channel row made up of a plurality of ink channels is formed on the second piezoelectric material substrate. An actuator member having a drive electrode formed in each ink channel and an extraction electrode electrically connected to the drive electrode; and an actuator member bonded to each of both surfaces of the actuator member. And a lid substrate that constitutes a common flow path that communicates with each ink channel, and a nozzle plate that is joined to the actuator member and has a nozzle hole in a portion corresponding to each ink channel. .

  According to the present invention, it is possible to improve the positional accuracy of the nozzles with respect to each ink channel, achieve high ejection stability, and realize a high-resolution inkjet head.

  A fifth aspect of the invention relates to an aspect of the ink jet head according to the fourth aspect of the invention, wherein each ink channel constituting the first channel row and each ink channel constituting the second channel row are: In the direction in which the plurality of ink channels constituting the channel row are arranged, the ink channels of one channel row are alternately arranged so as not to be in the same position as the ink channels of the other channel row. It is characterized by.

  According to the invention described in claim 5, it is possible to increase the density and resolution of the ink jet head.

  In order to achieve the above object, an image forming apparatus according to the present invention (invention according to claim 6) includes the ink jet head according to claim 4 or 5.

  According to the present invention, it is possible to improve image quality and realize a preferable image.

  According to the present invention, after the first piezoelectric material substrate and the second piezoelectric material substrate are integrated with the intermediate layer interposed therebetween, a plurality of ink channels are formed on each of the piezoelectric material substrates. In other words, since there is no need to bond the piezoelectric material substrates after forming the ink channels, there is no effect of variations in the alignment of the ink channels or variations in the thickness of the adhesive, and the positional accuracy of the nozzles relative to the ink channels As a result, it is possible to realize a high-resolution inkjet head with high ejection stability.

1 is an exploded perspective view of an inkjet head according to an embodiment of the present invention. Side sectional view of the inkjet head of FIG. Front sectional view showing a part of the inkjet head of FIG. Process drawing showing a manufacturing method of the inkjet head of FIG. Overall configuration diagram showing outline of inkjet recording apparatus Main part plan view showing the periphery of the printing unit of the ink jet recording apparatus Main block diagram showing the control system of the ink jet recording apparatus

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

[Configuration of inkjet head]
FIG. 1 is an exploded perspective view of an inkjet head according to an embodiment of the present invention. 2 is a side sectional view of the inkjet head of FIG. 1, and FIG. 3 is a front sectional view showing a part (actuator member) of the inkjet head of FIG. 2 shows a cross-sectional structure at a position corresponding to the line AA in FIG.

  The ink jet head 10 shown in FIG. 1 includes an actuator member 12 in which a plurality of groove portions to be ink channels 20 are formed on both surfaces (upper end surface 12c and lower end surface 12d), and a plurality of nozzles 22 corresponding to each ink channel 20. The formed nozzle plate 14, the cover substrate 16 (16 A, 16 B) constituting one wall surface of each ink channel 20, and the flow channel formation in which the groove portion serving as the common flow channel 24 and the hole portion serving as the ink supply port 26 are formed. It is mainly comprised from the board | substrate 18 (18A, 18B).

  The actuator member 12 has a configuration in which the first piezoelectric material substrate 30A and the second piezoelectric material substrate 30B are integrated with the intermediate layer (electrode) 28 interposed therebetween, and each of the piezoelectric material substrates 30A, 30B. Each is provided with a channel row 32 (first channel row 32A, second channel row 32B) comprising a plurality of ink channels 20.

  As shown in FIG. 3, each ink channel 20A constituting the first channel row 32A and each ink channel 20B constituting the second channel row 32B are arranged in a direction in which a plurality of ink channels constituting the channel row are arranged. They are alternately arranged along (channel row direction; horizontal direction in FIG. 3). In other words, in each of the channel rows 32A and 32B, each ink channel (for example, 20A) in one channel row does not have the same position with respect to each ink channel (for example, 20B) in the other channel row in the channel row direction. The ink channels 20A and 20B are formed in a so-called staggered arrangement.

  The ink channels (grooves) 20 are parallel to each other and have the same shape, and are elongated from the front end surface 12a of the actuator member 12 toward the rear end surface 12b on the opposite side, and the front end surface 12a side is formed with a certain depth. It is formed so as to gradually become shallower as it approaches the rear end face 12b (see FIG. 2).

  Each of the piezoelectric material substrates 30 </ b> A and 30 </ b> B has a laminated structure including two layers of piezoelectric bodies 34 and 36. Each of the piezoelectric bodies 34 and 36 is made of a piezoelectric material having ferroelectricity, such as a lead zirconate titanate (PZT) ceramic material, and is subjected to polarization treatment in a direction away from each other. Specifically, the piezoelectric bodies 34A and 36A constituting the first piezoelectric material substrate 30A are respectively polarized in the directions of arrows P1 and P2 shown in FIG. 3, and the piezoelectric bodies constituting the second piezoelectric material substrate 30B. 34B and 36B are respectively polarized in the directions of arrows P3 and P4 shown in FIG.

  The piezoelectric materials constituting each of the piezoelectric bodies 34 and 36 may be the same or may be composed of different piezoelectric materials. However, it is preferable that the piezoelectric materials constituting each of the piezoelectric bodies 34 and 36 are the same from the viewpoint of making the piezoelectric characteristics of the piezoelectric bodies 34 and 36 uniform and stabilizing the discharge. In this example, the piezoelectric bodies 34 and 36 are made of the same ceramic material (PZT).

As shown in FIG. 2, a cover substrate 16A is joined to the upper end surface 12c of the actuator member 12, and one wall surface of each ink channel 20A formed on the first piezoelectric material substrate 30A by the cover substrate 16A. It is configured. A flow path forming substrate 18A is joined to the rear end surface 12b side of the cover substrate 16A, and each ink channel 20A communicates with a common flow path 24A constituted by the flow path forming substrate 18A. Note that the cover substrate 16A and the flow path forming substrate 18A may be formed of a single substrate (the same applies to a cover substrate 16B and a flow path forming substrate 18A described later).
Similarly, a cover substrate 16B and a flow path forming substrate 18B are joined to the lower end surface 12d of the actuator member 12, and one wall surface of each ink channel 20B formed on the second piezoelectric material substrate 30B by the cover substrate 16B. In addition, each ink channel 20B communicates with a common flow path 24B formed by the flow path forming substrate 18B.

  A nozzle plate 14 is joined to the front end surface 12 a of the actuator member 12. In the nozzle plate 14, a plurality of nozzles 22 corresponding to the respective ink channels 20 are formed in a staggered manner, and each nozzle 22 communicates with the corresponding ink channel 20.

  Drive electrodes 40 for applying a drive voltage are formed on the surfaces (side surfaces) of both side walls 38 of each ink channel (groove portion) 20. Further, in the shallow region of the ink channel 20, the drive electrode 40 is formed not only on the side surface but also on the bottom surface. On the upper end surface 12c and the lower end surface 12d of the actuator member 12, an extraction electrode 42 is formed for each ink channel on the rear side (rear end surface 12b side) of each ink channel 20, and each extraction electrode 42 corresponds to each. The drive electrode 40 provided on the side surface of the ink channel 20 is electrically connected.

  Further, one end of the flexible printed wiring board 44 (44A, 44B) is joined to the rear side (rear end surface 12b side) of the upper end surface 12c and the lower end surface 12d of the actuator member 12. The flexible printed wiring board 44 is formed with a conductive pattern corresponding to each extraction electrode 42, and the conductive pattern and each extraction electrode 42 are electrically connected. The other end of each flexible printed wiring board 44 is connected to a driving circuit (not shown) so that a predetermined driving voltage is applied from the driving circuit to each driving electrode 40 via the flexible printed wiring board 44. It has become.

  Next, the operation of the above-described inkjet head 10 will be described.

  In the state where each ink channel 20 is filled with ink via the ink supply port 26 and the common flow path 24, for example, when the ink channel 20A shown in FIG. 3A is selected according to the input image data, the selected ink channel 20A is selected. A predetermined drive voltage is applied to the drive electrode 40 formed on the inner wall of the ink channel 20A. At this time, electric fields in the directions Q1 and Q2 orthogonal to the polarization directions P1 and P2 of the piezoelectric bodies 34A and 36A are applied to the side walls 38 and 38 on both sides of the ink channel 20A, respectively. Due to the effect, the ink channel 20A is deformed in the inner direction (FIG. 3B). Due to this deformation, the volume of the ink channel 20A is reduced, the ink in the ink channel 20A is pressurized, and a part of the ink is ejected as droplets (ink droplets) from the nozzle 22 communicating with the ink channel 20A. . Thereafter, when the application of the drive voltage is stopped and the side walls 38 return to the original state, ink is supplied from the common flow path 24A to the ink channel 20A.

[Inkjet head manufacturing method]
Next, a method for manufacturing the inkjet head 10 according to the present embodiment will be described with reference to FIG. FIG. 4 is a process diagram showing a method of manufacturing the ink jet head 10 of FIG.

  First, the laminated structure 50 shown in FIG. This laminated structure 50 is obtained by alternately stacking piezoelectric bodies and electrodes, and includes a piezoelectric body 34A, an intermediate layer (electrode) 28, and a piezoelectric body 34B that constitute a part of the actuator member 12 shown in FIG. Polarizing external electrodes 52A and 52B are formed on both surfaces of the laminate made of the above. The external electrodes 52A and 52B are electrodes that are removed after the polarization treatment, as will be described later.

  Next, using the external electrodes 52A and 52B and the intermediate layer (electrode) 28 disposed on both surfaces of the piezoelectric bodies 34A and 34B, polarization processing is performed in the direction in which the polarization directions of the piezoelectric bodies 34A and 34B face each other. . That is, the piezoelectric bodies 34A and 34B are polarized in the directions of arrows P1 and P3 shown in FIG. After the polarization treatment, the external electrodes 52A and 52B formed on both surfaces of the laminated structure 50 are removed by a method such as polishing (FIG. 4B).

  Next, the piezoelectric bodies 36A and 36B polarized in opposite directions to the piezoelectric bodies 34A and 34B are bonded to both surfaces of the multilayer structure 50 shown in FIG. 4B (FIG. 4C). Specifically, the piezoelectric body 36A polarized in the direction P2 that is opposite to the polarization direction P1 of the piezoelectric body 34A is joined to the upper end surface 50a of the multilayer structure 50. Similarly, the piezoelectric body 36B polarized in the P4 direction, which is opposite to the polarization direction P3 of the piezoelectric body 34B, is joined to the lower end surface 50b of the multilayer structure 50. Thus, the actuator member 12 is obtained in which the first piezoelectric material substrate 30A and the second piezoelectric material substrate 30B are integrated with the intermediate layer (electrode) 28 interposed therebetween.

  Next, a plurality of groove portions to be the ink channels 20A and 20B are formed on both surfaces (upper end surface 12c and lower end surface 12d) of the actuator member 12 shown in FIG. 4C (FIG. 4D). At this time, when viewed from the front end surface (nozzle plate bonding surface) 12a side of the actuator member 12, each ink channel 20A formed on the first piezoelectric material substrate 30A and the second piezoelectric material substrate 30B are formed. The ink channels 20B are formed so as to be alternately arranged along the channel row direction (that is, the ink channels 20A and 20B are arranged in a staggered manner).

  Next, as shown in FIG. 4E, a plurality of extraction electrodes 42A and 42B are formed on both surfaces (upper end surface 12c and lower end surface 12d) of the actuator member 12, respectively. Each extraction electrode 42A, 42B is provided for each ink channel, and is formed on the rear side (the left end side in FIG. 4E) of each ink channel 20A, 20B.

  Next, as shown in FIG. 4F, the drive electrode 40 is formed on the side surface of the groove portion to be the ink channels 20A and 20B. At this time, the drive electrodes 40 are formed not only on the side surfaces but also on the bottom surfaces in the shallow regions of the ink channels 20A and 20B, and the drive electrodes formed on the side surfaces of the ink channels 20A and 20B respectively corresponding to the extraction electrodes 42A and 42B. Electrical connection with 40 is made.

  Next, as shown in FIG. 4G, the cover substrates 16A and 16B are bonded to both surfaces (the upper end surface 12c and the lower end surface 12d) of the actuator member 12, respectively. Thus, one wall surface of each ink channel 20A formed on the first piezoelectric material substrate 30A is constituted by the cover substrate 16A, and one wall surface of each ink channel 20B formed on the second piezoelectric material substrate 30B. The wall surface is composed of a cover substrate 16B.

  Next, as shown in FIG. 4 (h), the nozzle plate 14 is joined to the front end surface 12 a of the actuator member 12 in a state where the nozzles 22 and the corresponding ink channels 20 communicate with each other.

  Next, as shown in FIG. 4I, the flow path forming substrate in a state where at least the rear end portions of the extraction electrodes 42A and 42B are exposed on both surfaces (the upper end surface 12c and the lower end surface 12d) of the actuator member 12. 18A and 18B are joined respectively.

  Finally, as shown in FIG. 4 (j), one end of each of the flexible printed wiring boards 44A and 44B is joined to the rear end portions of both surfaces (the upper end surface 12c and the lower end surface 12d) of the actuator member 12, respectively. Electrical connection between the conductive patterns formed on the wiring boards 44A and 44B and the extraction electrodes 42A and 42B is performed. The other ends of the flexible printed wiring boards 44A and 44B are connected to a drive circuit (not shown). In this way, the ink jet head 10 according to the present embodiment can be obtained.

  According to this manufacturing method, the first piezoelectric material substrate 30A and the second piezoelectric material substrate 30B constituting the actuator member 12 are integrally configured via the intermediate layer (electrode) 28, and then each piezoelectric material substrate 30B is formed. Since the groove portions to be the ink channels 20A and 20B are formed in the conductive material substrates 30A and 30B, respectively, a process that requires the alignment of the ink channels 20A and 20B becomes unnecessary, and the nozzle 22 for each of the ink channels 20A and 20B. Position accuracy is improved, and a high-resolution inkjet head with high density and high ejection stability can be realized.

[Image forming apparatus]
Next, an ink jet recording apparatus as an embodiment of the image forming apparatus according to the present invention will be described.

  FIG. 5 is an overall configuration diagram showing an outline of the ink jet recording apparatus. As shown in FIG. 5, the inkjet recording apparatus 100 includes a printing unit 112 having a plurality of inkjet heads (hereinafter simply referred to as “heads”) 112K, 112C, 112M, and 112Y provided for each color of ink. , An ink storage / loading unit 114 that stores ink to be supplied to each of the heads 112K, 112C, 112M, and 112Y, a paper feeding unit 118 that supplies the recording paper 116, and a decurling unit that removes curl of the recording paper 116 120, a suction belt conveyance unit 122 that is arranged to face the nozzle surface (ink ejection surface) of the printing unit 112 and conveys the recording paper 116 while maintaining the flatness of the recording paper 116, and printing by the printing unit 112 A print detection unit 124 that reads the result; and a paper discharge unit 126 that discharges printed recording paper (printed matter) to the outside. That.

  In FIG. 5, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 118, but a plurality of magazines having different paper widths, paper quality, and the like may be provided side by side. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration using roll paper, a cutter 128 is provided as shown in FIG. 5, and the roll paper is cut into a desired size by the cutter 128. The cutter 128 includes a fixed blade 128A having a length equal to or larger than the conveyance path width of the recording paper 116, and a round blade 128B that moves along the fixed blade 128A. The fixed blade 128A is provided on the back side of the print. The round blade 128B is arranged on the printing surface side with the conveyance path interposed therebetween. Note that the cutter 128 is not necessary when cut paper is used.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Therefore, it is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 116 delivered from the paper supply unit 118 retains curl due to having been loaded in the magazine. In order to remove this curl, the decurling unit 120 applies heat to the recording paper 116 by the heating drum 130 in the direction opposite to the curl direction of the magazine. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  After the decurling process, the cut recording paper 116 is sent to the suction belt conveyance unit 122. The suction belt conveyance unit 122 has a structure in which an endless belt 133 is wound between rollers 131 and 132, and at least a portion facing the nozzle surface of the printing unit 112 and the sensor surface of the printing detection unit 124 is flat. It is configured to make.

  The belt 133 has a width that is wider than the width of the recording paper 116, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 5, an adsorption chamber 134 is provided at a position facing the nozzle surface of the print unit 112 and the sensor surface of the print detection unit 124 inside the belt 133 that is stretched between the rollers 131 and 132. The suction chamber 134 is sucked by the fan 135 to make a negative pressure, whereby the recording paper 116 on the belt 133 is sucked and held.

  The power of a motor (not shown) is transmitted to at least one of the rollers 131 and 132 around which the belt 133 is wound, whereby the belt 133 is driven in the clockwise direction in FIG. 5 and is held on the belt 133. The recording paper 116 is conveyed from left to right in FIG.

  Since ink adheres to the belt 133 when a borderless print or the like is printed, the belt cleaning unit 136 is provided at a predetermined position outside the belt 133 (an appropriate position other than the print region). Although details of the configuration of the belt cleaning unit 136 are not shown, for example, there are a method of niping a brush roll, a water absorption roll, etc., an air blowing method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a mode using a roller / nip conveyance mechanism instead of the suction belt conveyance unit 122 is also conceivable, if the roller / nip conveyance is performed in the printing area, the roller comes into contact with the printing surface of the paper immediately after printing, so that the image blurs. There is a problem that it is easy. Therefore, as in this example, suction belt conveyance that does not contact the image surface in the printing region is preferable.

  A heating fan 140 is provided on the upstream side of the printing unit 112 on the paper conveyance path formed by the suction belt conveyance unit 122. The heating fan 140 heats the recording paper 116 by blowing heated air onto the recording paper 116 before printing. Heating the recording paper 116 immediately before printing makes it easier for the ink to dry after landing.

  In the printing unit 112, black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side (left side in FIG. 5) along the conveyance direction (paper conveyance direction) of the recording paper 116. Heads 112K, 112C, 112M, and 112Y corresponding to each color ink are arranged. A color image can be formed on the recording paper 116 by ejecting the color ink from each of the heads 112K, 112C, 112M, and 112Y while conveying the recording paper 116.

  Each of the heads 112K, 112C, 112M, and 112Y corresponds to the inkjet head 10 shown in FIG. Each of the heads 112K, 112C, 112M, and 112Y is configured by a line-type head having a nozzle row having a length corresponding to the entire width (image formable width) of the recording paper 116 (see FIG. 6). Although not shown in the figure, a line type head having a nozzle row having a length corresponding to the entire width of the recording paper 116 as a whole by connecting a plurality of short heads corresponding to the ink jet head 10 to make the length long. It may be comprised.

  Each of the heads 112K, 112C, 112M, and 112Y reciprocates in a direction (main scanning direction) perpendicular to the paper conveyance direction (sub-scanning direction) with a short head having a nozzle row that is less than the full width of the recording paper 116. It may be composed of an operating serial type head.

  According to the aspect in which each of the heads 112K, 112C, 112M, and 112Y is formed of a line type head, the operation of relatively moving the recording paper 116 and the printing unit 112 in the paper transport direction (sub-scanning direction) is performed only once. Thus, an image can be recorded on the entire surface of the recording paper 116 in one sub-scan. Thereby, it is possible to perform high-speed printing as compared with an aspect in which each of the heads 112K, 112C, 112M, and 112Y is a serial head, and productivity can be improved.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink and dark ink are added as necessary. May be. For example, it is possible to add a head for ejecting light-colored ink such as light cyan and light magenta.

  As shown in FIG. 5, the ink storage / loading unit 114 has tanks that store inks of colors corresponding to the heads 112K, 112C, 112M, and 112Y, and each tank is connected via a conduit that is not shown. The heads 112K, 112C, 112M, and 112Y communicate with each other. Further, the ink storage / loading unit 114 includes notifying means (display means, warning sound generating means, etc.) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. is doing.

  The print detecting unit 124 includes an image sensor (line sensor or the like) for imaging the droplet ejection result of the printing unit 112, and means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor. Function as.

  The print detection unit 124 of this example is composed of a line sensor having a light receiving element array that is wider than at least the ink ejection width (image recording width) of each head 112K, 112C, 112M, 112Y. The line sensor includes an R sensor row in which photoelectric conversion elements (pixels) provided with red (R) color filters are arranged in a line, a G sensor row provided with green (G) color filters, The color separation line CCD sensor includes a B sensor array provided with a blue (B) color filter. Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  The print detection unit 124 reads the test pattern printed by the heads 112K, 112C, 112M, and 112Y for each color, and detects the ejection of each head. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 142 is provided following the print detection unit 124. The post-drying unit 142 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by blocking the paper holes by pressurization. There is an effect to.

  A heating / pressurizing unit 144 is provided following the post-drying unit 142. The heating / pressurizing unit 144 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 145 having a predetermined uneven surface shape while heating the image surface, and transfers the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 126. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 100 is provided with sorting means (not shown) for switching the paper discharge path in order to select the printed matter of the main image and the printed matter of the test print and send them to the respective discharge units 126A and 126B. ing. Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by the cutter (second cutter) 148. The cutter 148 is provided immediately before the paper discharge unit 126, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 148 is the same as that of the first cutter 128 described above, and includes a fixed blade 148A and a round blade 148B. Although not shown, the paper output unit 126A for the target prints is provided with a sorter for collecting prints according to print orders.

  FIG. 7 is a principal block diagram showing a control system of the inkjet recording apparatus 100. The inkjet recording apparatus 100 includes a communication interface 170, a system controller 172, an image memory 174, a motor driver 176, a heater driver 178, a print control unit 180, an image buffer memory 182, a head driver 184, and the like.

  The communication interface 170 is an interface unit that receives image data sent from the host computer 186. As the communication interface 170, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 186 is taken into the inkjet recording apparatus 100 via the communication interface 170 and temporarily stored in the image memory 174.

  The image memory 174 is a storage unit that temporarily stores an image input via the communication interface 170, and data is read and written through the system controller 172. The image memory 174 is not limited to a memory composed of semiconductor elements, and a magnetic medium such as a hard disk may be used.

  The system controller 172 is a control unit that controls the communication interface 170, the image memory 174, the motor driver 176, the heater driver 178, and the like. The system controller 172 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 186, read / write control of the image memory 174, and the like, and a transport motor 188 and heater 189. A control signal for controlling is generated.

  The motor driver 176 is a driver (drive circuit) that drives the motor 188 in accordance with an instruction from the system controller 172. The heater driver 178 is a driver that drives the heater 189 of the post-drying unit 142 and other units in accordance with an instruction from the system controller 172.

  The print control unit 180 has a signal processing function for performing various processes such as processing and correction for generating a print control signal from the image data in the image memory 174 in accordance with the control of the system controller 172. The control unit supplies a control signal (dot data) to the head driver 184. The required signal processing is performed in the print control unit 180, and the ejection amount and ejection timing of the ink droplets of the heads 112K, 112C, 112M, and 112Y are controlled via the head driver 184 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 180 includes an image buffer memory 182, and image data, parameters, and other data are temporarily stored in the image buffer memory 182 when image data is processed in the print control unit 180. In FIG. 7, the image buffer memory 182 is shown in a mode associated with the print control unit 180, but it can also be used as the image memory 174. Also possible is an aspect in which the print controller 180 and the system controller 172 are integrated and configured with one processor.

  The head driver 184 generates a drive signal for driving the ink channels 20 (see FIG. 1) of the heads 112K, 112C, 112M, and 112Y of each color based on the dot data given from the print control unit 180, and the ink channel 20 The generated drive signal is supplied to the drive electrode 40 corresponding to. The head driver 184 may include a feedback control system for keeping the driving conditions of the heads 112K, 112C, 112M, and 112Y constant.

  As described with reference to FIG. 5, the print detection unit 124 is a block including a line sensor. And the detection result is provided to the print control unit 180.

  The print control unit 180 performs various corrections on the heads 112K, 112C, 112M, and 112Y based on information obtained from the print detection unit 124 as necessary.

  As mentioned above, although the manufacturing method of the inkjet head of this invention, the inkjet head, and the image forming apparatus were demonstrated in detail, this invention is not limited to the above example, In the range which does not deviate from the summary of this invention, it is various improvement. It goes without saying that or may be modified.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet head, 12 ... Actuator member, 14 ... Nozzle plate, 16 ... Cover substrate, 18 ... Channel formation substrate, 20 ... Ink channel, 22 ... Nozzle, 24 ... Common channel, 26 ... Ink supply port, 28 ... Intermediate layer (electrode), 30 ... Piezoelectric material substrate, 32 ... Ink channel array, 34, 36 ... Piezoelectric body, 38 ... Side wall, 40 ... Electrode, 42 ... Extraction electrode, 44 ... Flexible printed wiring board, 100 ... Inkjet recording apparatus

Claims (6)

A plurality of parallel ink channels separated by partition walls made of a piezoelectric material are formed, and the partition walls are deformed according to the drive voltage applied to the drive electrodes formed on the inner walls of the ink channels. An ink jet head manufacturing method for discharging ink filled in the ink channel from a nozzle communicating with the ink channel,
An actuator member forming step of forming an actuator member in which the first piezoelectric material substrate and the second piezoelectric material substrate are integrated with an intermediate layer interposed therebetween;
After the actuator member forming step is performed, a first channel row composed of a plurality of ink channels is formed on the first piezoelectric material substrate, and a plurality of ink channels are formed on the second piezoelectric material substrate. An ink channel forming step of forming a second channel row,
An electrode forming step of forming a drive electrode in each ink channel and forming an extraction electrode connected to the drive electrode;
A lid substrate joining step for joining a lid substrate constituting a common flow path communicating with each ink channel while forming one wall surface of each ink channel on each of both surfaces of the actuator member;
A nozzle plate joining step of joining a nozzle plate having a nozzle hole in a portion corresponding to each ink channel to the actuator member;
A method for manufacturing an ink jet head, comprising: In the manufacturing method of the ink-jet head according to claim 1,
Each ink channel constituting the first channel row and each ink channel constituting the second channel row are inks of one channel row with respect to the direction in which the plurality of ink channels constituting the channel row are arranged. A method of manufacturing an ink jet head, characterized in that the channels are alternately arranged so that the channels do not coincide with the ink channels of the other channel row. In the manufacturing method of the ink-jet head according to claim 1 or 2,
The actuator member forming step includes a step of forming an external electrode for polarization, a step of polarizing a piezoelectric body constituting a piezoelectric material substrate, and a step of removing the external electrode after the polarization processing. A method for manufacturing an inkjet head. A plurality of parallel ink channels separated by a partition made of a piezoelectric material, and the partition is deformed according to a driving voltage applied to a drive electrode formed on an inner wall of the ink channel. An ink jet head for discharging the ink filled in the ink channel from a nozzle communicating with the ink channel,
The first piezoelectric material substrate and the second piezoelectric material substrate are integrated with an intermediate layer interposed therebetween, and a first channel row composed of a plurality of ink channels is formed on the first piezoelectric material substrate. The second piezoelectric material substrate is formed with a second channel row composed of a plurality of ink channels, and further, a drive electrode is formed in each ink channel and an extraction electrode electrically connected to the drive electrode An actuator member formed with
A lid substrate that is bonded to each of both surfaces of the actuator member, constitutes one wall surface of each ink channel, and constitutes a common flow path communicating with each ink channel;
A nozzle plate joined to the actuator member and having a nozzle hole in a portion corresponding to each ink channel;
An ink jet head comprising: The inkjet head according to claim 4,
Each ink channel constituting the first channel row and each ink channel constituting the second channel row are inks of one channel row with respect to the direction in which the plurality of ink channels constituting the channel row are arranged. An inkjet head, wherein the channels are arranged alternately so that the channels do not coincide with the ink channels of the other channel row.   An image forming apparatus comprising the ink jet head according to claim 4.

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