JP2017116766A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress leading ends of nozzles from being soiled by a toner on a sheet.SOLUTION: A fixing device 7 is a device that can spray a charged fixing solution L to a recording sheet (sheet P) through electrostatic spraying, and comprises: a second electrode 72 that supports the recording sheet; a storage part 73 that stores the fixing solution L therein; a plurality of nozzles N that are communicated with the storage part 73 and project from the storage part 73 toward the second electrode 72; and a rib 90 that projects toward the second electrode 72 farther than the leading ends of the nozzles N and arranged at an interval with the second electrode 72, the rib 90 for protecting the plurality of nozzles from the recording sheet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing device that fixes a toner image on a sheet, and an image forming apparatus including the fixing device.

2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus is known that includes a fixing device that melts toner by heating a transferred toner image to fix the toner on a sheet. The fixing device has a heating element such as a halogen heater or a ceramic heater to melt the toner. The melted toner is pressed against the paper and fixed on the paper. Such a fixing device is widely used because it has a high fixing speed and good image quality. However, an image forming apparatus using such a heat fixing type fixing device consumes a large amount of power because it heats toner, and thus is not suitable for power saving of the image forming apparatus.
In order to solve the above problems, there is an image forming apparatus including a fixing device that fixes a toner image on a sheet by applying a fixing solution for dissolving or swelling the toner to the toner on the sheet. This fixing device does not require a heat treatment for melting the toner as in the heat fixing method, has low power consumption, and is excellent in power saving. As a method of applying the fixing solution to the toner image, a method of applying the fixing solution to the roller surface and applying the fixing solution on the roller in contact with the toner image, or a method of applying the fixing solution to the toner image in a non-contact manner by a sprayer or the like Etc. are known (see Patent Document 1).
A fixing device that applies a fixing liquid by a roller has a structure in which the roller and a toner image are in contact with each other. Therefore, it is known that such a fixing device has a problem that an unfixed toner image moves (offsets) to the roller side when the roller and the toner image come into contact with each other. On the other hand, since the fixing device using the sprayer can apply the fixing liquid to the toner image in a non-contact manner, no offset occurs.
The fixing device of Patent Document 1 includes a spray unit that sprays a fixing liquid toward a sheet, and a second charging unit to which a voltage is applied.

JP 2009-69256 A

  However, in the prior art, when the paper is curled, if the paper contacts the tip of the nozzle of the spraying means, the tip of the nozzle may be stained by the toner image on the paper. Further, when an electric field is formed between the spraying means and the second charging means, the paper may float to the spraying means side, and the tip of the nozzle may be soiled by the toner image on the paper. When the tip of the nozzle becomes dirty in this way, the toner adhering to the tip of the nozzle is sprayed onto the paper together with the fixing liquid during spraying, which may affect fixing.

  Accordingly, an object of the present invention is to prevent the nozzle tip from being contaminated by toner on the paper.

The present invention that solves the above-described problems is a fixing device that can spray a fixing solution toward a recording sheet by electrostatic spraying, and includes a storage portion that can store a fixing solution therein, and a storage portion that communicates with the storage portion. An electric field between a plurality of nozzles projecting from the container, a first electrode that contacts the fixing solution, and a first electrode capable of applying a voltage to the fixing solution, and a fixing solution at the tip of the plurality of nozzles. And a rib for protecting the plurality of nozzles from the recording sheet.
The plurality of nozzles and the rib extend toward the second electrode.
A distance between the second electrode and the plurality of nozzles is longer than a distance between the second electrode and the rib.

  According to this configuration, when the recording sheet is transported between the plurality of nozzles and the second electrode, if the recording sheet tries to approach the nozzle side, the recording sheet is further moved to the nozzle side by the rib. Therefore, it is possible to suppress the nozzle tip from being contaminated by the developer on the recording sheet.

  In the above-described configuration, the rib may extend from the housing portion toward the second electrode.

  According to this, compared with the structure which provides a rib in the member different from an accommodating part, a rib can be accurately arrange | positioned with respect to each nozzle.

  Moreover, the above-mentioned structure WHEREIN: The said rib may be arrange | positioned between two nozzles.

  Further, in the above-described configuration, it has a plurality of horizontal nozzle rows in which a plurality of nozzles are arranged in an orthogonal direction orthogonal to the recording sheet conveyance direction, and the rib is more than the horizontal nozzle row on the most upstream side in the conveyance direction. You may have the 1st part arrange | positioned upstream.

  In the above-described configuration, the rib may have a second portion that is disposed downstream of the most downstream lateral nozzle row in the recording sheet conveyance direction.

  In the above-described configuration, the rib may include a third portion that extends continuously from the first portion to the second portion and is connected to the first portion and the second portion.

  According to this, since the rib extends from the upstream side to the downstream side of the plurality of nozzles, the rib moves the paper to each nozzle side while the paper passes between the plurality of nozzles and the second electrode. Can be suppressed.

  Moreover, the above-mentioned structure WHEREIN: The said rib may incline with respect to the said conveyance direction.

  According to this, a plurality of nozzles can be arranged in a balanced manner.

  Further, in the above-described configuration, a plurality of the ribs are provided at intervals in an orthogonal direction orthogonal to the transport direction, and the first portion of one of the two ribs adjacent in the orthogonal direction; and The second portion of the other rib may overlap with the conveyance direction when viewed from the conveyance direction.

  Further, in the above-described configuration, the rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the rib in the orthogonal direction. A plurality of second ribs disposed on the other side of the first portion, wherein the plurality of first ribs and the plurality of second ribs are alternately arranged in the orthogonal direction. It may be arranged.

  In the above-described configuration, the first portion of the first rib and the first portion of the second rib are connected, and the second portion of the first rib and the second portion of the second rib. And may be connected.

  By connecting each rib in this way, the strength of each rib can be improved.

  Further, in the above-described configuration, the rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the rib in the orthogonal direction. A plurality of second ribs disposed on the other side of the first portion, wherein the plurality of first ribs is on the one side with respect to a center in the orthogonal direction of the horizontal nozzle row. The plurality of second ribs may be arranged on the other side with respect to the center in the orthogonal direction of the horizontal nozzle row.

  According to this, since the plurality of first ribs and the plurality of second ribs having different inclination directions are arranged in a balanced manner with respect to the center of the horizontal nozzle row, the recording sheet guided by the ribs is arranged in the conveyance direction. On the other hand, it can suppress moving diagonally. In addition, since the plurality of first ribs and the plurality of second ribs are arranged so as to gradually spread away from the center of the horizontal nozzle row toward the downstream side in the transport direction, each first rib and each second rib Can extend the wrinkles of the recording sheet.

  In the above-described configuration, the first portion of the first rib and the first portion of the second rib that are closest to the center in the orthogonal direction of the horizontal nozzle row may be connected.

  By connecting each rib in this way, the strength of each rib can be improved.

  Further, in the above-described configuration, the rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the rib in the orthogonal direction. A plurality of second ribs disposed on the other side of the first portion, wherein the plurality of first ribs are on the other side with respect to the center of the horizontal nozzle row in the orthogonal direction. The plurality of second ribs may be arranged on the one side with respect to the center in the orthogonal direction of the horizontal nozzle row.

  According to this, since the plurality of first ribs and the plurality of second ribs having different inclination directions are arranged in a balanced manner with respect to the center of the horizontal nozzle row, the recording sheet guided by the ribs is arranged in the conveyance direction. On the other hand, it can suppress moving diagonally. In addition, since the plurality of first ribs and the plurality of second ribs are arranged so as to gradually narrow toward the center of the horizontal nozzle row toward the downstream side in the transport direction, for example, in the cross section orthogonal to the transport direction In the case where the recording sheet is curled so that the central portion of the recording sheet is convex toward the nozzle side, the bulging central portion of the recording sheet is secondly formed by the first and second ribs that are gradually narrowed. It can be pushed into the electrode side, and the curling of the recording sheet can be corrected.

  In the above-described configuration, the second portion of the first rib and the second portion of the second rib that are closest to the center in the orthogonal direction of the horizontal nozzle row may be connected.

  By connecting each rib in this way, the strength of each rib can be improved.

  Further, in the above-described configuration, the plurality of nozzles include two first nozzles that are adjacent to each other in a direction orthogonal to the conveyance direction of the recording sheet, and the ribs are formed with respect to the two first nozzles. The first end, which is disposed at a position shifted in the transport direction, and is the end on the first nozzle side of the rib, is disposed between the centers of the two first nozzles in the orthogonal direction. Also good.

  According to this, compared with the structure which arrange | positions a 1st edge part so that it may align with a nozzle in a conveyance direction, the length of the conveyance direction of an accommodating part can be shortened, for example.

  In the above-described configuration, the plurality of nozzles include two second nozzles adjacent in an orthogonal direction orthogonal to the transport direction, and the rib includes the first nozzle and the second nozzle in the transport direction. The second end portion, which is the end portion on the second nozzle side of the rib, may be disposed between the centers of the two second nozzles in the orthogonal direction.

  According to this, compared with the structure which arrange | positions a 1st end part and a 2nd end part with a nozzle in a conveyance direction, the length of the conveyance direction of the nozzle group which consists of a some nozzle can be shortened.

  In the configuration described above, the shortest distance between the first end and the first nozzle may be equal to the shortest distance between the two first nozzles.

  According to this, a 1st end part and two 1st nozzles can be arrange | positioned closest.

  In the above-described configuration, the plurality of nozzles may be configured such that the spray amount per unit area is substantially equal at each position in the orthogonal direction orthogonal to the conveyance direction of the recording sheet.

  According to this, the fixing solution can be sprayed substantially uniformly on the developer image on the recording sheet.

  Further, in the above-described configuration, a plurality of nozzle rows including a plurality of nozzles arranged in the transport direction may be provided in the orthogonal direction, and each of the plurality of nozzle rows may be configured by the same number of nozzles. Good.

  According to this, the fixing solution can be sprayed substantially uniformly on the developer image on the recording sheet.

  In the above-described configuration, the pitch between two adjacent nozzles of the plurality of nozzles may be 2 mm or more and less than 10 mm.

  In the above-described configuration, the housing portion, the plurality of nozzles, and the rib may be integrally formed of resin.

  According to this, an accommodating part, a some nozzle, and a rib can be manufactured easily.

  Further, an image forming apparatus according to the present invention is a nozzle for spraying liquid toward a recording sheet, communicating with a storage section that stores liquid, a first electrode that contacts the liquid, and the storage section. A nozzle projecting from the housing portion along the first direction, and a rib projecting from the housing portion along the first direction, and separated from the housing portion in the first direction than the tip of the nozzle. An electrostatic spraying device having a rib for positioning and protecting the plurality of nozzles from the recording sheet.

  Even in this configuration, since the rib restricts the recording sheet from moving further to the nozzle side, it is possible to prevent the nozzle tip from being contaminated by the developer on the recording sheet.

  According to the present invention, it is possible to prevent the nozzle tip from being soiled by the developer on the recording sheet.

1 is a diagram illustrating a laser printer including a fixing device according to an embodiment of the present invention. FIG. 4 is a perspective view (a) of the fixing head as viewed from obliquely above and a perspective view (b) of as viewed from obliquely below. FIG. 3 is a bottom view of the fixing head as viewed from below. FIG. 9 is a bottom view showing Modification 1 of the fixing head. FIG. 9 is a bottom view showing Modification Example 2 of the fixing head. FIG. 9 is a bottom view showing a third modification of the fixing head. FIG. 10 is a bottom view showing Modification 4 of the fixing head. FIG. 10 is a bottom view showing Modification 5 of the fixing head. FIG. 10 is a bottom view showing Modification 6 of the fixing head. FIG. 10 is a bottom view showing Modification 7 of the fixing head. It is the enlarged view (a) which shows the relationship between the 3rd rib shown in FIG. 10, and a 1st nozzle, and the enlarged view (b) which shows the comparative example corresponding to the form of FIG. 11 (a). FIG. 13 is a bottom view (a) showing a modified example 8 of the fixing head and a bottom view (b) showing a comparative example corresponding to the embodiment of FIG. FIG. 14 is a bottom view (a) showing a modified example 9 of the fixing head and a bottom view (b) showing a comparative example corresponding to the embodiment of FIG. 13 (a). FIG. 15A is a bottom view showing a modified example 10 of the fixing head, and FIG. 15B is a bottom view showing a comparative example corresponding to the embodiment of FIG. FIG. 14 is a bottom view showing Modification 11 of the fixing head. FIG. 16 is a bottom view showing Modification 12 of the fixing head. FIG. 18A is a bottom view showing a modified example 13 of the fixing head, and FIG. 17B is a bottom view showing a comparative example corresponding to the embodiment of FIG. FIG. 19 is a bottom view (a) showing a modified example 14 of the fixing head and a bottom view (b) showing a comparative example corresponding to the embodiment of FIG. FIG. 16 is a bottom view showing Modification 15 of the fixing head.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of the laser printer will be described, and then the features of the present invention will be described in detail.

  In the following description, directions will be described in the directions shown in FIG. That is, in FIG. 1, the right side toward the paper surface is “front side”, the left side toward the paper surface is “rear side”, the back side toward the paper surface is “right side”, and the front side toward the paper surface is “left side”. To do. In addition, the vertical direction toward the page is defined as the “vertical direction”.

  As shown in FIG. 1, a laser printer 1 includes a housing 2, a feeder unit 3 for feeding paper P as an example of a recording sheet, and an image forming unit 4 for forming an image on the paper P. It has.

  The feeder unit 3 includes a paper feed tray 31 that is detachably attached to the lower portion of the housing 2 and a paper feed mechanism 32 that feeds the paper P in the paper feed tray 31 toward the image forming unit 4. Yes.

  The image forming unit 4 is accommodated in the housing 2 and mainly includes a scanner unit 5, a process cartridge 6, a transfer roller TR, and a fixing device 7 as an example of an electrostatic spraying device. .

  The scanner unit 5 is provided in an upper part of the housing 2 and includes a laser light emitting unit, a polygon mirror, a lens, a reflecting mirror, and the like (not shown). In the scanner unit 5, a laser beam is irradiated on the surface of a photosensitive drum 61 described later by high-speed scanning.

  The process cartridge 6 can be attached to and detached from the housing 2. The process cartridge 6 includes a photosensitive drum 61 on which an electrostatic latent image is formed, a charger (not shown), a toner storage unit 62 that stores toner as an example of a developer, and a toner in the toner storage unit 62. A supply roller 63 and a developing roller 64 for supplying to 61 are provided.

  In the process cartridge 6, a charger (not shown) uniformly charges the surface of the rotating photosensitive drum 61. The scanner unit 5 emits a laser beam to the surface of the photosensitive drum 61 to expose the surface of the photosensitive drum 61, thereby forming an electrostatic latent image based on the image data on the surface of the photosensitive drum 61.

  Next, the rotationally driven developing roller 64 supplies toner to the electrostatic latent image on the photosensitive drum 61 to form a toner image on the surface of the photosensitive drum 61. Thereafter, the toner image carried on the surface of the photosensitive drum 61 is attracted to the transfer roller TR and transferred onto the paper P when the paper P is conveyed between the photosensitive drum 61 and the transfer roller TR.

  The fixing device 7 is a device that fixes the toner image on the paper P by spraying the charged fixing liquid L toward the toner image on the paper P by electrostatic spraying. The configuration of the fixing device 7 will be described in detail later.

  On the downstream side of the fixing device 7, a downstream side conveyance roller 81 for conveying the paper P discharged from the fixing device 7 to the downstream side is provided. The paper P transported by the downstream transport roller 81 is transported to the paper discharge roller R and is discharged onto the paper discharge tray 21 from the paper discharge roller R.

Next, the configuration of the fixing device 7 will be described in detail.
The fixing device 7 includes a fixing head 71 for spraying the fixing liquid L and a second electrode 72. The second electrode 72 is disposed below the fixing head 71 so as to face the fixing head 71, and supports the sheet P conveyed toward the bottom of the fixing head 71 from below. It should be noted that rollers (photosensitive drum 61, transfer roller TR, downstream-side transport roller 81, and the like) on the upstream and downstream sides of the fixing device 7 are arranged in a direction from the front to the rear of the fixing head 71, and will be described later. A transport mechanism for transporting the paper P is formed between the two.

  As the fixing solution, a solution in which a solute that dissolves toner is dispersed in a solvent having a high dielectric constant can be used in order to perform electrostatic spraying well and perform fixing. Safe water can be used as a solvent having a high dielectric constant. That is, in this embodiment, the toner is dissolved by a so-called oil-in-water emulsion in which a solute that dissolves the toner is dispersed in water. That is, a fixing solution in which a solute insoluble or hardly soluble in water as a solvent is dispersed in water is used. Solutes include aliphatic monocarboxylic acid esters such as ethyl laurate, butyl laurate, isopropyl laurate, ethyl myristate, butyl myristate, isopropyl myristate, ethyl palmitate, butyl palmitate, isopropyl palmitate, fat As an aliphatic dicarboxylic acid ester system, diethyl succinate, dibutyl succinate, As an aliphatic tricarboxylic acid ester system, o acetyl citrate triethyl, o acetyl citrate tributyl, As aliphatic dicarboxylic acid dialkoxyalkyl system as diethoxyethyl succinate Ethylene carbonate and propylene carbonate can be used as dibutoxyethyl succinate and carbonate ester. These solutes have a function of softening the toner.

  In addition, a surfactant may be added in order to form an emulsion satisfactorily. As the surfactant, an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be used. Examples of anionic surfactants include higher fatty acid salts such as sodium laurate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, alkyl sulfate salts such as sodium dodecyl sulfate, and polyethoxyethylene lauryl ether sodium sulfate. Polyoxyethylene alkylaryl ether sulfate salts such as oxyethylene alkyl ether sulfate salts and sodium polyoxyethylene nonylphenyl ether sulfate can be used. As the cationic surfactant, aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, and imidazolinium salts can be used. Nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonylphenyl ether, sorbitan higher fatty acid esters such as sorbitan monolaurate, Use polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene higher fatty acid esters such as polyoxyethylene monolaurate, and sucrose fatty acid esters such as sucrose laurate. Can do.

The fixing head 71 includes an accommodating portion 73 that accommodates the fixing liquid L therein, a nozzle group Gn that communicates with the accommodating portion 73 and sprays the fixing liquid L toward the toner image, and an accommodating portion 73. And a first electrode 74 for applying a voltage to the fixing liquid L in each nozzle N. The nozzle group Gn is composed of all the nozzles N included in the fixing head 71. In other words, the nozzle group Gn has a plurality of horizontal nozzle rows composed of a plurality of nozzles N arranged in the left-right direction in the transport direction. In the embodiment shown in FIG. 3, the nozzle group Gn is formed by six horizontal nozzle rows. The inner diameter of the nozzle N is formed between 0.1 mm and 1.0 mm.
The first electrode 74 is provided so as to penetrate the upper wall 73A of the housing portion 73 from the top to the bottom, the lower end portion is disposed in the fixing liquid L in the housing portion 73, and the upper end portion is a voltage application (not shown). Connected to a control device having a unit.

  The second electrode 72 is an electrode for contacting the paper P and forming a potential difference (electric field) between the fixing liquid L in the nozzle N and the paper P, and is separated from the tip of each nozzle N by a predetermined distance. In addition, the nozzles N are arranged so as to face each other. Here, the predetermined distance is a distance larger than the thickness of the paper P, and is set to a distance at which electrostatic spraying can be suitably performed by experiments or simulations. The second electrode 72 may be grounded, or a voltage smaller than the voltage applied to the first electrode 74 may be applied. Further, the voltage applied to the second electrode 72 may be a voltage having a reverse polarity to the voltage applied to the first electrode 74. When the second electrode 72 is grounded, the voltage applied to the first electrode 74 is preferably 1 kv to 10 kv.

When a voltage is applied to the first electrode 74, an electric field is formed in the space near the tip of the nozzle N. Specifically, the fixing liquid L in the storage unit 73 is pressurized by a pressurizing device (not shown). As a result, the fixing liquid L is supplied toward the tip of the nozzle N. An electric field is formed between the fixing liquid L at the tip of the nozzle N and the second electrode 72. Then, at the tip of the nozzle N, the fixing liquid L is pulled by an electric field, so that a so-called Taylor cone is formed. The electric field concentrates on the tip of the Taylor cone, and the fixing liquid L is torn off from the tip of the Taylor cone, thereby generating fine droplets.
The droplet-shaped fixing liquid L sprayed from the nozzle N is positively charged. On the other hand, the paper P is substantially in a zero potential state. For this reason, the droplet-like fixing liquid L flies toward the paper P by the Coulomb force and adheres to the paper P and the toner image.

  The first electrode 74 and the second electrode 72 configured in this way form a potential difference for forming a potential difference between the fixing liquid L in the nozzle N and the paper P conveyed at a position away from the nozzle N. Has become a department.

  As shown in FIG. 2A, the accommodating portion 73 is a rectangular container that is long in the left-right direction, that is, the width direction of the paper P (orthogonal direction orthogonal to the transport direction), and includes an upper wall 73A and a front wall. 73B, rear wall 73C, left wall 73D, right wall 73E, and lower wall 73F.

  As shown in FIG. 2B, the plurality of nozzles N are substantially cylindrical nozzles that communicate with the inside of the housing portion 73, and downward from the lower wall 73 </ b> F of the housing portion 73 as an example of the first direction. It protrudes and gradually decreases in diameter as it goes downward. The plurality of nozzles N are arranged in the width direction of the paper P, that is, in the left-right direction, and are arranged in the conveyance direction of the paper P, that is, in the front-rear direction.

  A rib 90 that guides the paper P between the second electrode 72 and the second electrode 72 is provided on the lower wall 73 </ b> F of the housing portion 73. The accommodating part 73, the nozzle group Gn, and the rib 90 are integrally formed with resin.

  The rib 90 has three first ribs 91 and three second ribs 92. Each of the ribs 91 and 92 extends downward from the lower wall 73F of the accommodating portion 73, and the lower end surface thereof is disposed below the tip of each nozzle N (see FIG. 1). In other words, each of the ribs 91 and 92 protrudes toward the second electrode 72 from the tips of the plurality of nozzles N, and is disposed at a distance from the second electrode 72. That is, the distance between each rib 91, 92 and the second electrode 72 is shorter than the distance between the tip of each nozzle N and the second electrode 72.

  As shown in FIG. 3, each of the ribs 91 and 92 is disposed so as to incline with respect to the transport direction of the paper P and to cross the nozzle group Gn from the upstream side to the downstream side in the transport direction. Specifically, the first rib 91 includes a first portion 91A disposed on the upstream side of the nozzle group Gn, a second portion 91B disposed on the downstream side of the nozzle group Gn, and a second portion from the first portion 91A. The first portion 91A and the third portion 91C connected to the second portion 91B extend continuously to the portion 91B. In other words, the first portion 91A is arranged upstream of the most upstream side nozzle row among the plurality of rows of nozzles constituting the nozzle group Gn, and the second portion 91B is the most downstream side nozzle row. It is arranged downstream. Similarly, the second rib 92 includes a first portion 92A disposed on the upstream side of the nozzle group Gn, a second portion 92B disposed on the downstream side of the nozzle group Gn, and a second portion from the first portion 92A. The first portion 92A and the third portion 92C connected to the second portion 92B extend continuously to the portion 92B. In other words, the first portion 92A is arranged upstream of the most upstream side nozzle row among the plurality of rows of nozzles constituting the nozzle group Gn, and the second portion 92B is the most downstream side nozzle row. It is arranged downstream.

In the first rib 91, the second portion 91B is disposed on one side (the left side in the drawing) of the first portion 91A in the left-right direction. That is, the distance between the left wall 73D and the second part 91B in the left-right direction is longer than the distance between the left wall 73D and the first part 91A in the left-right direction.
In contrast, in the second rib 92, the second portion 92B is disposed on the other side (the right side in the drawing) opposite to the first portion 92A in the left-right direction. That is, the distance between the left wall 73D and the second part 92B in the left-right direction is shorter than the distance between the left wall 73D and the first part 92A in the left-right direction. The three first ribs 91 and the three second ribs 92 are arranged so as to be alternately arranged in the left-right direction.

  Specifically, the second rib 92, the first rib 91, and the second rib 92 are arranged in order from the center line CL side on one side (left side in the drawing) with respect to the center line CL in the left-right direction of the nozzle group Gn (horizontal nozzle row). Are alternately arranged, and on the other side, first ribs 91, second ribs 92, and first ribs 91 are alternately arranged in order from the center line CL side. The ribs 92, 91, 92 on one side of the center line CL and the ribs 91, 92, 91 on the other side are symmetrical with respect to the center line CL.

  The nozzle group Gn has a plurality of nozzle rows Ln including two nozzles N arranged in the transport direction in the left-right direction. Thereby, the nozzle group Gn is configured such that the spray amount per unit area is substantially equal at each position in the left-right direction.

  The plurality of nozzle rows Ln includes a first nozzle row Ln1 in which two nozzles N constituting the nozzle row Ln are arranged at a predetermined first pitch P1, and two nozzles N constituting the nozzle row Ln from the first pitch P1. And a second nozzle row Ln2 arranged at a large second pitch P2. The second pitch P2 is twice as large as the first pitch P1.

  The first nozzle row Ln1 is arranged along the first rib 91 or the second rib 92 on the left side or the right side of the first rib 91 or the second rib 92 in the drawing. The second nozzle row Ln2 is arranged with the first rib 91 or the second rib 92 interposed between the two nozzles N constituting the second nozzle row Ln2.

  The plurality of nozzles N are respectively arranged so that the shape connecting the centers of the three closest nozzles N becomes a substantially equilateral triangle. In other words, among the plurality of nozzles N, the shape connecting the centers of two nozzles N adjacent to each other at the shortest distance in the left-right direction and the center of one nozzle N closest to these two nozzles N is It is a substantially equilateral triangle.

  The shortest distance between two nozzles N adjacent in the left-right direction, the shortest distance between the nozzle N and the first rib 91, and the shortest distance between the nozzle N and the second rib 92 are substantially the same value. . Here, when the shortest distance between each of the ribs 91 and 92 and the nozzle N is set to be equal to or longer than the shortest distance between the two nozzles N, the fixing liquid L sprayed from each nozzle N is charged. It is difficult to be adversely affected by electrolysis generated from the ribs 91 and 92, and the fixing liquid L can be sprayed well. In addition, the pitch of the two nozzles N adjacent in the left-right direction, specifically, the pitch of the two nozzles N arranged in the shortest distance can be set in a range of 2 mm or more and less than 10 mm, for example.

The nozzle group Gn and the ribs 91 and 92 described above can be appropriately arranged by the following design method.
First, a plurality of horizontal nozzle rows each including a plurality of nozzles N (including nozzles Nv1 and Nv2 indicated by broken lines) arranged at a predetermined third pitch P3 in the left-right direction are arranged in the transport direction. At this time, the plurality of horizontal nozzle rows are shifted by a half of the third pitch P3 in the left-right direction so that the shape connecting the centers of the three closest nozzles N becomes a substantially equilateral triangle. To do.

  Thereafter, the plurality of nozzles Nv1 arranged in an oblique direction with respect to the transport direction are removed, and the ribs 91 and 92 are disposed in the removed portions. Next, the extra nozzle Nv2 is removed so that the number of the plurality of nozzles N arranged in the transport direction is two.

  In other words, the plurality of nozzles N are arranged in principle at the vertices of a plurality of equilateral triangles arranged so as to be spread, and the portion in which the ribs 91 and 92 are arranged and the arrangement of the ribs 91 and 92 in the conveying direction. It is configured not to be disposed in a portion where it is necessary to reduce the number of nozzles. In the following description, for the sake of convenience, a configuration in which each nozzle N is arranged at the apex of an equilateral triangle is also called a close-packed arrangement.

Next, the function and effect of the rib 90 will be described.
As shown in FIG. 1, the paper P on which the toner image is transferred between the photosensitive drum 61 and the transfer roller TR is conveyed toward the rib 90 and the second electrode 72 by a guide member (not shown). While the paper P is being transported between the rib 90 and the second electrode 72, if the paper P moves to the nozzle N side due to the curled state of the paper P or the like, it is below the tip of the nozzle N. Further movement of the sheet P to the nozzle N side is restricted by the rib 90 positioned at the position. Thereby, it is possible to suppress the tip of the nozzle N from being contaminated by the toner on the paper P.

As described above, according to the present embodiment, the following effects can be obtained in addition to the effects described above.
Since the rib 90 is provided in the accommodating portion 73 so as to extend from the accommodating portion 73 toward the second electrode 72 side, for example, the rib 90 is made to correspond to each nozzle N in comparison with a structure in which the rib is provided on a member different from the accommodating portion. Can be arranged with high accuracy.

  Since the ribs 91 and 92 extend from the upstream side to the downstream side of the nozzle group Gn, the rib 90 causes the nozzles N side of the paper P to pass while the paper P passes between the nozzle group Gn and the second electrode 72. The movement to can be suppressed.

  Since the ribs 91 and 92 are inclined with respect to the transport direction, the plurality of nozzles N can be arranged in a well-balanced manner.

  The ribs 92, 91, 92 on one side of the center line CL and the ribs 91, 92, 91 on the other side are symmetrical with respect to the center line CL, and are therefore guided by the rib 90. It is possible to suppress the sheet P to be moved obliquely with respect to the transport direction.

  Since the plurality of nozzle rows Ln arranged in the left-right direction are composed of the same number (two) of nozzles N, the fixing liquid L can be sprayed substantially uniformly on the toner image on the paper P.

  Since the accommodating part 73, the nozzle group Gn, and the rib 90 were integrally formed with resin, the accommodating part 73, the nozzle group Gn, and the rib 90 can be manufactured easily.

  In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below. In the following description, the same reference numerals are given to members having substantially the same structure as in the above embodiment, and the description thereof is omitted. In the drawings used in the following description, a part of the accommodating portion 73 is appropriately enlarged and illustrated.

  In the embodiment, the plurality of first nozzle rows Ln1 are arranged along the first rib 91 or the second rib 92, but the present invention is not limited to this. For example, as shown in FIG. 4, the plurality of first nozzle rows Ln1 are arranged close to the wide space side of the substantially triangular space formed between the first rib 91 and the second rib 92. Also good. In the form of FIG. 4, the nozzle group Gn has six horizontal nozzle rows in the transport direction that are composed of a plurality of nozzles N arranged in the left-right direction. Also in this embodiment, the first portions 91A and 92A are arranged upstream of the most upstream horizontal nozzle row of the plurality of horizontal nozzle rows constituting the nozzle group Gn, and the second portions 91B and 92B are It arrange | positions downstream from the horizontal nozzle row | line | column of the most downstream side.

  In the above-described embodiment, the rib 90 is configured by the two types of the first rib 91 and the second rib 92 that are inclined differently, but the present invention is not limited to this, as shown in FIG. You may comprise only the some 1st rib 91. FIG. Specifically, in the form of FIG. 5, the plurality of first ribs 91 are provided at intervals in the left-right direction, and the first of the first ribs 91 is one of the two first ribs 91 adjacent in the left-right direction. The portion 91A and the second portion 91B of the other first rib 91 overlap each other when viewed from the transport direction. In this embodiment, the nozzles N are arranged in a close-packed manner, and a plurality of nozzle rows Ln arranged in the left-right direction are each composed of four nozzles N arranged in the transport direction. In other words, in the form of FIG. 5, the nozzle group Gn has ten horizontal nozzle rows in the transport direction that are composed of a plurality of nozzles N arranged in the left-right direction. Also in this embodiment, the first portion 91A is disposed upstream of the most upstream side nozzle row among the plurality of rows of nozzle rows constituting the nozzle group Gn, and the second portion 91B is disposed on the most downstream side. It arrange | positions downstream from a horizontal nozzle row.

  Further, as shown in FIG. 6, the first portion 91 </ b> A of the first rib 91 and the first portion 92 </ b> A of the second rib 92 are connected to form one fourth portion 91 </ b> D, and the second portion of the first rib 91 is formed. The fifth portion 91E may be configured by connecting the portion 91B and the second portion 92B of the second rib 92. Specifically, the fourth portion 91D is formed so as to extend along the transport direction from substantially the same position as the most upstream nozzle N in the transport direction to a position upstream of the nozzle N. In addition, the fifth portion 91E is formed so as to extend in the transport direction from a position that is substantially the same as the nozzle N on the most downstream side in the transport direction to a position on the downstream side of the nozzle N. In this embodiment as well, the nozzles N are arranged in a close-packed manner, and a plurality of nozzle rows Ln arranged in the left-right direction are each composed of four nozzles N arranged in the transport direction. In other words, in the form of FIG. 6, the nozzle group Gn has ten horizontal nozzle rows in the transport direction that are composed of a plurality of nozzles N arranged in the left-right direction. Also in this embodiment, the first portions 91A and 92A are arranged upstream of the most upstream horizontal nozzle row among the plurality of horizontal nozzle rows constituting the nozzle group Gn, and the second portions 91B and 92B are It arrange | positions downstream from the horizontal nozzle row | line | column of the most downstream side.

  By connecting the first rib 91 and the second rib 92 in this way, the strength of the ribs 91 and 92 can be improved.

  In the above-described embodiment, the nozzles N are arranged closest to each other. However, the present invention is not limited to this, and for example, the nozzles N may be arranged as shown in FIG. The form of FIG. 7 is a form in which the rib 90 is configured by only a plurality of second ribs 92. Also in this embodiment, the first portion 92A is arranged upstream of the most upstream side nozzle row of the plurality of rows of nozzles constituting the nozzle group Gn, and the second portion 92B is located on the most downstream side. It arrange | positions downstream from a horizontal nozzle row.

  The nozzle group Gn has a plurality of horizontal nozzle rows Ls composed of a plurality of nozzles N arranged in the left-right direction, specifically, 10 rows in the transport direction. In the following description, in order from the upstream side in the transport direction, the horizontal nozzle rows Ls located in the first row and the second row are collectively referred to as a first nozzle group G1, and each horizontal nozzle located in the third row and the fourth row. The row Ls is collectively referred to as a second nozzle group G2. Similarly, the horizontal nozzle rows Ls located in the fifth row and the sixth row are referred to as a third nozzle group G3, and the horizontal nozzle rows Ls located in the seventh row and the eighth row are designated as a fourth nozzle group G4. Each horizontal nozzle row Ls located in the ninth row and the tenth row is referred to as a fifth nozzle group G5.

  The nozzle groups G1 to G5 are arranged closest to each other, but the second nozzle group G2 is arranged in one of the left and right directions by a pitch that is 1/5 of the third pitch P3 described above with respect to the first nozzle group G1. The third nozzle group G3 is shifted to one side in the left-right direction by a 2/5 pitch of the third pitch P3 with respect to the first nozzle group G1. The fourth nozzle group G4 is shifted to the left and right by one third of the third pitch P3 with respect to the first nozzle group G1, and the fifth nozzle group G5 is third with respect to the first nozzle group G1. The pitch P3 is shifted to one of the left and right directions by a pitch of 4/5.

  In this way, by shifting the nozzle groups G1 to G5 by 1/5 pitch in the left-right direction, the spray region (circular region) of the fixing liquid L sprayed from each nozzle N onto the paper P is set to 1 in the left-right direction. Since it can be finely overlapped at / 5 pitch, the spray amount per unit area can be made substantially equal at each position in the left-right direction. Such a configuration of the nozzle groups G1 to G5 can be similarly applied to the ribs 90 arranged as shown in FIGS.

  Further, the rib 90 may be configured as shown in FIG. In this embodiment, the rib 90 has three first ribs 91 and three second ribs 92 that are substantially the same as those shown in FIG. 3, but the arrangement of the first ribs 91 and the second ribs 92. However, it is different from the form of FIG. In the form of FIG. 8, the nozzle group Gn has ten horizontal nozzle rows in the transport direction, each of which includes a plurality of nozzles N arranged in the left-right direction. Also in this embodiment, the first portions 91A and 92A are arranged upstream of the most upstream horizontal nozzle row of the plurality of horizontal nozzle rows constituting the nozzle group Gn, and the second portions 91B and 92B are It arrange | positions downstream from the horizontal nozzle row | line | column of the most downstream side.

  Specifically, each first rib 91 in which the second portion 91B is disposed on one side (the left side in the drawing) of the first portion 91A in the left-right direction is on one side with respect to the center line CL in the left-right direction of the nozzle group Gn. Has been placed. In contrast, each second rib 92 in which the second portion 92B is disposed on the other side (right side in the drawing) of the second portion 92B in the left-right direction is on the other side with respect to the center line CL in the left-right direction of the nozzle group Gn. Is arranged. That is, the first ribs 91 and the second ribs 92 are line symmetric with respect to the center line CL as an axis of symmetry.

  The first portions 91A and 92A of the first rib 91 and the second rib 92 that are closest to the center line CL of the nozzle group Gn are connected to each other to form one fourth portion 91D. 4th site | part 91D is comprised similarly to the form of FIG. In this embodiment as well, each nozzle N is arranged in a close-packed manner, and a plurality of nozzle rows Ln are each composed of four nozzles N arranged in the transport direction.

  According to this embodiment, the first ribs 91 and the second ribs 92 having different inclination directions are arranged with a good balance with respect to the center line CL of the nozzle group Gn, and therefore are guided by the ribs 91 and 92. It is possible to suppress the sheet P to be moved obliquely with respect to the transport direction. Further, the first ribs 91 and the second ribs 92 are arranged so as to gradually spread away from the center line CL of the nozzle group Gn toward the downstream side in the transport direction. P can be extended.

  Further, the rib 90 may be configured as shown in FIG. This form has a structure in which the upstream side and the downstream side in the transport direction in the form of FIG. 8 are reversed. In the form shown in FIG. 9, the nozzle group Gn has ten horizontal nozzle rows each including a plurality of nozzles N arranged in the left-right direction in the transport direction. Also in this embodiment, the first portions 91A and 92A are arranged upstream of the most upstream horizontal nozzle row of the plurality of horizontal nozzle rows constituting the nozzle group Gn, and the second portions 91B and 92B are It arrange | positions downstream from the horizontal nozzle row | line | column of the most downstream side.

  Specifically, each first rib 91 in which the second portion 91B is disposed on one side (the left side in the drawing) of the second portion 91B in the left-right direction is on the other side with respect to the center line CL in the left-right direction of the nozzle group Gn It is arranged on the right side of the figure. On the other hand, each second rib 92 in which the second portion 92B is disposed on the other side of the first portion 92A in the left-right direction is disposed on one side with respect to the center line CL in the left-right direction of the nozzle group Gn. Yes. That is, the first ribs 91 and the second ribs 92 are line symmetric with respect to the center line CL as an axis of symmetry.

  The second portions 91B and 92B of the first rib 91 and the second rib 92 that are closest to the center line CL of the nozzle group Gn are connected to each other to form one fifth portion 91E. The fifth portion 91E is configured in the same manner as in the form of FIG. In this embodiment as well, each nozzle N is arranged in a close-packed manner, and a plurality of nozzle rows Ln are each composed of four nozzles N arranged in the transport direction.

  According to this configuration, the first ribs 91 and the second ribs 92 having different inclination directions are arranged in a well-balanced manner with respect to the center line CL of the nozzle group Gn, and thus are guided by the ribs 91 and 92. It is possible to suppress the sheet P to be moved obliquely with respect to the transport direction. In addition, since each first rib 91 and each second rib 92 are arranged so as to gradually narrow toward the center line CL of the nozzle group Gn toward the downstream side in the transport direction, for example, a cross section orthogonal to the transport direction When the paper P is curled so that the central portion of the paper P is convex toward the nozzle group Gn, the ribs 91 and 92 that gradually narrow the central portion of the paper P that is bulged. Thus, the sheet can be pushed into the second electrode 72 side, and the curling of the paper P can be corrected.

  Further, the rib 90 may be configured as shown in FIG. In this embodiment, the plurality of nozzles N are all closely arranged, and the plurality of nozzle rows Ln are each composed of three nozzles N arranged in the transport direction. In other words, the nozzle group Gn in this form has a plurality of horizontal nozzle rows Ls including a plurality of nozzles N arranged in the left-right direction in the transport direction. In the following description, the plurality of horizontal nozzle rows Ls are arranged in order from the upstream side in the transport direction, the first horizontal nozzle row Ls1, the second horizontal nozzle row Ls2, the third horizontal nozzle row Ls3, the fourth horizontal nozzle row Ls4, Also referred to as the 5 horizontal nozzle row Ls5 and the 6th horizontal nozzle row Ls6.

  The rib 90 has six third ribs 93 disposed on the upstream side in the transport direction of the nozzle group Gn and six fourth ribs 94 disposed on the downstream side in the transport direction of the nozzle group Gn. Each of the ribs 93 and 94 extends from the housing portion 73 toward the second electrode 72, and the lower surface thereof is disposed closer to the second electrode 72 than the tip of each nozzle N. In the following description, for convenience, each nozzle N constituting the horizontal nozzle row Ls adjacent to each of the ribs 93 and 94 in the transport direction is also referred to as a first nozzle N1. That is, for example, in the form of FIG. 10, the nozzles N constituting the first horizontal nozzle row Ls1 and the sixth horizontal nozzle row Ls6 are also referred to as first nozzles N1, respectively.

  As shown in FIG. 11A, the third rib 93 is formed in a predetermined length in the transport direction, and is shifted upstream in the transport direction with respect to two first nozzles N1 adjacent in the left-right direction. Placed in position. The first end 93A, which is the end of the third rib 93 on the first nozzle N1 side, is disposed between the centers of the two first nozzles N1 in the left-right direction. The first end portion 93A has a curved surface with a circular arc in cross section when facing the first nozzle N1, and the shortest distance D1 between the first end portion 93A and the first nozzle N1 is two second It is equal to the shortest distance D2 between 1 nozzle N1.

  Thus, by arranging the first end portion 93A so as to be opposed between the two first nozzles N1 in the transport direction, for example, the first end portion 93A as shown in FIG. Compared to the structure in which the first nozzle N1 is separated from the first nozzle N1 by the distance D1, the third rib 93 can be brought closer to the first nozzle N1 in the transport direction.

  As shown in FIG. 10, the fourth rib 94 has substantially the same configuration as the third rib 93, specifically, a structure in which the direction of the third rib 93 is reversed in the transport direction. More specifically, the first end 94A, which is the end of the fourth rib 94 on the first nozzle N1 side, is disposed between the centers of the two first nozzles N1 in the left-right direction. In addition, the first end 94A has a curved surface with a circular arc when viewed from the cross section, and the shortest distance D1 between the first end 94A and the first nozzle N1 is the two second nozzles N1. It is equal to the shortest distance D2 between 1 nozzle N1.

  According to this embodiment, for example, the ribs 93 and 94 can be arranged closer to the nozzle group Gn side than the structure in which the first end portions 93A and 94A are arranged so as to be aligned with the first nozzle N1 in the transport direction. Therefore, the length of the accommodating portion 73 in the transport direction can be shortened. Further, since the shortest distance D1 between the first end portions 93A, 94A and the first nozzle N1 and the shortest distance D2 between the two first nozzles N1 are the same length, the first end portions 93A, 94A and the first The nozzles N1 can be arranged closest.

  In the form of FIG. 10, the third rib 93 is arranged adjacent to the upstream side of the first horizontal nozzle row Ls1, and the fourth rib 94 is arranged adjacent to the downstream side of the sixth horizontal nozzle row Ls6. However, the present invention is not limited to this. For example, as shown in FIGS. 12 to 14, the third ribs 93 and the fourth ribs 94 are disposed adjacent to the horizontal nozzle rows Ls other than the first horizontal nozzle row Ls1 and the sixth horizontal nozzle row Ls6 in the transport direction. May be.

  In the form shown in FIG. 12A, the third rib 93 is formed so as to extend from a position on the upstream side of the first horizontal nozzle row Ls1 to a position adjacent to the second horizontal nozzle row Ls2, and its first end portion. 93A is disposed between the centers of the two first nozzles N1 constituting the second horizontal nozzle row Ls2. Specifically, in the first end portion 93A of the third rib 93, the shortest distance D1 between the two first nozzles N1 constituting the second horizontal nozzle row Ls2 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  The fourth rib 94 is formed so as to extend from a position on the downstream side of the sixth horizontal nozzle row Ls6 to a position adjacent to the fifth horizontal nozzle row Ls5, and a first end portion 94A of the fourth horizontal nozzle row Ls5 extends. It arrange | positions between each center of the two 1st nozzles N1 to comprise. Specifically, in the first end portion 94A of the fourth rib 94, the shortest distance D1 between the two first nozzles N1 constituting the fifth horizontal nozzle row Ls5 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  In this embodiment, since the third rib 93 is arranged so as to cross the first horizontal nozzle row Ls1, the nozzle Ns scheduled to be arranged in the portion where the third rib 93 is arranged in the first horizontal nozzle row Ls1. , Rearrangement is performed downstream of the sixth horizontal nozzle row Ls6. Similarly, since the fourth rib 94 is arranged so as to cross the sixth horizontal nozzle row Ls6, the nozzle Ns scheduled to be arranged in the portion of the sixth horizontal nozzle row Ls6 where the fourth rib 94 is arranged. Is rearranged upstream of the first horizontal nozzle row Ls1. As a result of such an arrangement change, a plurality of nozzle rows Ln arranged in the left-right direction are each composed of three nozzles N arranged in the transport direction.

  On the other hand, as shown in FIG. 12B, when the third rib 93 and the fourth rib 94 are arranged at a distance D1 from the first nozzle N1 in the transport direction, the ribs 93 are arranged. , 94 are positioned farther from the first nozzle N1 in the transport direction than in the form of FIG. Therefore, in the form of FIG. 12A, the distance between the third rib 93 and the fourth rib 94 in the transport direction can be made smaller than the form of FIG. 12B (D3 <D4). The paper P can be smoothly transferred from the third rib 93 to the fourth rib 94.

  In the form shown in FIG. 13A, the third rib 93 is formed so as to extend from a position on the upstream side of the first horizontal nozzle row Ls1 to a position adjacent to the third horizontal nozzle row Ls3, and its first end portion. 93A is disposed between the centers of the two first nozzles N1 constituting the third horizontal nozzle row Ls3. Specifically, in the first end portion 93A of the third rib 93, the shortest distance D1 between the two first nozzles N1 constituting the third horizontal nozzle row Ls3 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  The fourth rib 94 is formed to extend from a position on the downstream side of the sixth horizontal nozzle row Ls6 to a position adjacent to the fourth horizontal nozzle row Ls4, and a first end portion 94A of the fourth horizontal nozzle row Ls4 extends. It arrange | positions between each center of the two 1st nozzles N1 to comprise. Specifically, in the first end portion 94A of the fourth rib 94, the shortest distance D1 between the two first nozzles N1 constituting the fourth horizontal nozzle row Ls4 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  In this embodiment, since the third rib 93 is arranged so as to cross the first horizontal nozzle row Ls1 and the second horizontal nozzle row Ls2, the portion of the horizontal nozzle rows Ls1, Ls2 where the third rib 93 is arranged is arranged. The three nozzles Ns that are to be arranged are rearranged downstream of the sixth horizontal nozzle row Ls6. Of the three rearranged nozzles Ns, the two nozzles Ns constituting the first horizontal nozzle row Ls1 do not overlap the third rib 93, but the shortest distance from the third guide 93 is less than D1. Because it has become, it is rearranged.

  Similarly, since the fourth rib 94 is arranged so as to cross the sixth horizontal nozzle row Ls6 and the fifth horizontal nozzle row Ls5, a portion of the horizontal nozzle rows Ls6, Ls5 where the fourth rib 94 is arranged. The three nozzles Ns that are scheduled to be disposed in the rear side are rearranged upstream of the first horizontal nozzle row Ls1. As a result of such an arrangement change, a plurality of nozzle rows Ln are each composed of three nozzles N arranged in the transport direction.

  Even in this configuration, as shown in FIG. 13B, the third rib 93 and the fourth rib 94 are arranged in the carrying direction in comparison with the structure in which the third rib 93 and the fourth rib 94 are arranged at a distance D1 from the first nozzle N1 in the carrying direction. The distance between the third rib 93 and the fourth rib 94 can be reduced (D5 <D6).

  In the form shown in FIG. 14A, the third rib 93 is formed to extend from a position on the upstream side of the first horizontal nozzle row Ls1 to a position adjacent to the fourth horizontal nozzle row Ls4, and its first end portion. 93A is disposed between the centers of the two first nozzles N1 constituting the fourth horizontal nozzle row Ls4. Specifically, in the first end portion 93A of the third rib 93, the shortest distance D1 between the two first nozzles N1 constituting the fourth horizontal nozzle row Ls4 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  The fourth rib 94 is formed so as to extend from a position on the downstream side of the sixth horizontal nozzle row Ls6 to a position adjacent to the third horizontal nozzle row Ls3, and a first end portion 94A of the fourth horizontal nozzle row Ls3 extends. It arrange | positions between each center of the two 1st nozzles N1 to comprise. Specifically, in the first end portion 94A of the fourth rib 94, the shortest distance D1 between the two first nozzles N1 constituting the third horizontal nozzle row Ls3 is equal to the shortest distance D2 between the two first nozzles N1. Are arranged as follows.

  In this embodiment, since the third rib 93 is arranged so as to cross from the first horizontal nozzle row Ls1 to the third horizontal nozzle row Ls3, the portion where the third rib 93 is arranged in each of the horizontal nozzle rows Ls1 to Ls3. The plurality of nozzles Ns that are scheduled to be disposed in the rear side of the sixth horizontal nozzle row Ls6 are changed in position. In addition, regarding the first horizontal nozzle row Ls1, the two nozzles Ns whose shortest distance from the third rib 93 is equal to or greater than D1 are also rearranged, but this is moved in consideration of the overall shape of the nozzle group Gn. These two nozzles Ns do not have to be rearranged.

  Similarly, since the fourth rib 94 is arranged so as to cross from the sixth horizontal nozzle row Ls6 to the fourth horizontal nozzle row Ls4, a plurality of nozzles Ns are arranged upstream of the first horizontal nozzle row Ls1. It has been converted. As a result of such an arrangement change, a plurality of nozzle rows Ln are each composed of three nozzles N arranged in the transport direction.

  Also in this embodiment, as shown in FIG. 14B, the third rib 93 and the fourth rib 94 are arranged in the carrying direction in comparison with the structure in which the third nozzle 93 and the fourth rib 94 are arranged apart from each other in the carrying direction by the distance D1. The distance between the third rib 93 and the fourth rib 94 can be reduced (D7 <D8).

  In the form shown in FIG. 15, the rib 90 has a plurality of fifth ribs 95 arranged in the nozzle group Gn. The fifth rib 95 extends from the accommodating portion 73 toward the second electrode 72, and the lower surface thereof is disposed on the second electrode 72 side than the tip of each nozzle N. The fifth rib 95 is disposed between the second horizontal nozzle row Ls2 and the fourth horizontal nozzle row Ls4 in the transport direction, and has a predetermined length (a length greater than the diameter of the nozzle N) in the transport direction. Is formed. In the following description, for convenience, the nozzle N constituting the horizontal nozzle row Ls adjacent to the downstream side of the fifth rib 95 is also referred to as the first nozzle N1, and the horizontal nozzle row Ls adjacent to the upstream side of the fifth rib 95. Is also referred to as a second nozzle N2.

  The first end 95A, which is the end of the fifth rib 95 on the first nozzle N1 side, is disposed between the centers of the two first nozzles N1 in the left-right direction. The first end portion 95A has a curved surface whose cross section is a circular arc when facing each first nozzle N1, and the shortest distance D1 between the first end portion 95A and the first nozzle N1 is two first nozzles. It is equal to the shortest distance D2 between N1.

  The second end 95B, which is the end of the fifth rib 95 on the second nozzle N2 side, is disposed between the centers of the two second nozzles N2 in the left-right direction. The second end 95B has a curved surface with a circular arc shape in cross section when viewed from the second nozzle N2, and the shortest distance D1 between the second end 95B and the second nozzle N2 is two second nozzles. It is equal to the shortest distance D2 between N2.

  By disposing the first end portion 95A and the second end portion 95B in this way, for example, at least one of the first end portion 95A and the second end portion 95B is distanced from the first nozzle N1 or the second nozzle N2 in the transport direction. Compared with the structure in which only D1 is arranged apart from each other, it is possible to suppress an increase in the interval between the second horizontal nozzle row Ls2 and the fourth horizontal nozzle row Ls4, and it is possible to shorten the length of the nozzle group Gn in the transport direction. .

  In this embodiment, the nozzle N is rearranged as described in the embodiment of FIG.

  The form shown in FIG. 16 is a form in which the length of the fifth rib 95 in the transport direction is made larger than the form of FIG. Specifically, in this embodiment, the first end 95A of the fifth rib 95 is arranged between the centers of the two first nozzles N1 constituting the fifth horizontal nozzle row Ls5, and the second end 95B is the first end. It arrange | positions between each center of the 2nd 2 nozzles N2 which comprise 1 horizontal nozzle row Ls1.

  According to this embodiment, the same effect as that of the embodiment of FIG. 15 can be obtained, and the length of the fifth rib 95 in the transport direction is larger than that of the embodiment of FIG. It can be carried out. In this embodiment, the nozzle N is rearranged as described in the embodiment of FIG.

  The form shown in FIG. 17A is a form in which the fifth rib 95 is disposed between the fifth horizontal nozzle row Ls5 and the second horizontal nozzle row Ls2 so as to be inclined with respect to the transport direction. Specifically, in this embodiment, in the left-right direction, the first end portion 95A of the fifth rib 95 is disposed between the centers of the two first nozzles N1 constituting the fifth horizontal nozzle row Ls5, and the second The end portion 95B is disposed between the centers of the two second nozzles N2 constituting the second horizontal nozzle row Ls2. In this embodiment, the nozzle N is rearranged as described in the embodiment of FIG.

  On the other hand, as shown in FIG. 17B, when the fifth rib 95 is disposed along the transport direction between the fifth horizontal nozzle row Ls5 and the second horizontal nozzle row Ls2, for example, Since the two end portions 95B must be arranged away from the second nozzle N2 by a distance D1 in the transport direction, the length of the fifth rib 95 in the transport direction is reduced. Therefore, in the form of FIG. 17A, the length of the fifth rib 95 in the transport direction can be increased as compared with the form of FIG. 17B (D9> D10).

  The form shown in FIG. 18A is a form in which the length of the fifth rib 95 in the transport direction is made larger than the form shown in FIG. Specifically, in this form, the first end 95A of the fifth rib 95 is disposed between the centers of the two first nozzles N1 constituting the sixth horizontal nozzle row Ls6, and the second end 95B is the first end. It arrange | positions between each center of the 2nd 2 nozzles N2 which comprise 1 horizontal nozzle row Ls1. In this embodiment, the nozzle N is rearranged as described in the embodiment of FIG.

  On the other hand, as shown in FIG. 18B, when the fifth rib 95 is disposed along the transport direction between the first horizontal nozzle row Ls1 and the sixth horizontal nozzle row Ls6, for example, Since the two end portions 95B must be arranged away from the second nozzle N2 by a distance D1 in the transport direction, the length of the fifth rib 95 in the transport direction is reduced. Therefore, in the form of FIG. 18A, the length of the fifth rib 95 in the transport direction can be increased (D11> D12) compared to the form of FIG. 18B.

  In the form shown in FIG. 19, the nozzle group Gn includes a sixth nozzle group G6 in which a plurality of nozzles N are arranged closest to each other at a predetermined pitch, and a plurality of nozzles N are arranged closest to each other at a pitch larger than the predetermined pitch. Two seventh nozzle groups G7. The sixth nozzle group G6 is disposed between the two seventh nozzle groups G7 in the transport direction. The spray amount of the seventh nozzle group G7 is larger than the spray amount of the sixth nozzle group G6.

  In this form, the rib 90 has a plurality of sixth ribs 96 and a plurality of seventh ribs 97. The sixth rib 96 is formed so as to extend in the transport direction from a position on the upstream side of the seventh nozzle group G7 on the upstream side to a position between the two nozzles N on the most upstream side. An end 96A on the downstream side of the sixth rib 96 faces the second nozzle N from the upstream side in the transport direction.

  The seventh rib 97 is formed so as to extend in the transport direction from a position on the downstream side of the seventh nozzle group G7 on the downstream side to a position between the two nozzles N on the most downstream side. The upstream end 97A of the seventh rib 97 faces the second nozzle N from the downstream side in the transport direction.

  Even in this form, the ribs 96 and 97 can prevent the sheet P from coming into contact with the nozzles N. Further, since the spray amount of the seventh nozzle group G7 is larger than the spray amount of the sixth nozzle group G6, the spray region (circular shape) of the fixing liquid L sprayed on the paper P from each nozzle N arranged at a large pitch. Can be overlapped in the left-right direction, and the spray amount per unit area can be made substantially equal at each position in the left-right direction.

  In the above embodiment, the second electrode 72 is exemplified as the support member for supporting the paper P. However, the present invention is not limited to this, and is disposed between the second electrode and the nozzle, for example, to support the paper from below. It may be a supporting member. In that case, it is preferable to provide a sheet conveyance guide along the rib 90 also on the support member.

  In the embodiment, the second electrode 72 is disposed so as to face the tip of each nozzle N of the fixing head 71. However, the present invention is not limited to this, and the nozzle and the first electrode are viewed from the direction in which the nozzle protrudes. The second electrode may be arranged so that the two electrodes do not overlap. For example, the second electrode may be arranged so as to be shifted upstream or downstream in the transport direction with respect to the nozzle. Even in this case, when the paper in contact with the second electrode faces the tip of the nozzle, a potential difference is formed between the fixing liquid in the nozzle and the paper, and electrostatic spraying can be performed.

  In the above embodiment, the present invention is applied to the laser printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a color printer, a copying machine, and a multifunction machine. .

In the embodiment, the paper P such as a thick paper, a postcard, and a thin paper is exemplified as an example of the recording sheet. However, the present invention is not limited to this, and may be an OHP sheet, for example.
In the above-described embodiment, the photosensitive drum 61 is exemplified as the photosensitive member. However, the present invention is not limited to this, and may be, for example, a belt-shaped photosensitive member.

  In the said embodiment, although the 1st electrode 74 was arrange | positioned inside the accommodating part 73, this invention is not limited to this, For example, a nozzle and an accommodating part are formed with electroconductive members, such as a metal, and a nozzle or an accommodating part A voltage may be applied to. In this case, the nozzle or the container to which the voltage is applied functions as the first electrode. Alternatively, the housing portion may be formed of a non-conductive member such as resin, the nozzle may be formed of a conductive member such as metal, and a voltage may be applied to the nozzle. In this case, the nozzle functions as the first electrode.

  The ribs 91 and 92 do not need to be completely continuous in the transport direction, and may be interrupted in the middle of the transport direction.

  Each of the ribs 91 and 92 may be a separate member from the accommodating portion 73. Only the ribs 91 and 92 may be formed as separate units from the accommodating portion.

7 Fixing Device 72 Second Electrode 73 Housing Portion 90 Rib Gn Nozzle Group L Fixing Solution N Nozzle P Paper

Claims (29)

A fixing device capable of spraying a fixing liquid toward a recording sheet by electrostatic spraying,
An accommodating portion capable of accommodating the fixer therein;
A plurality of nozzles communicating with the housing portion and projecting from the housing portion;
A first electrode in contact with the fixing solution, the first electrode capable of applying a voltage to the fixing solution;
A second electrode capable of forming an electric field with the fixer at the tip of the plurality of nozzles;
A rib for protecting the plurality of nozzles from the recording sheet,
The plurality of nozzles and the ribs extend toward the second electrode,
The fixing device according to claim 1, wherein a distance between the second electrode and the plurality of nozzles is longer than a distance between the second electrode and the rib.   The fixing device according to claim 1, wherein the rib extends from the housing portion toward the second electrode.   The fixing device according to claim 1, wherein the rib is disposed between two nozzles. Having a plurality of horizontal nozzle rows in which a plurality of nozzles are arranged in an orthogonal direction orthogonal to the recording sheet conveyance direction;
4. The fixing device according to claim 1, wherein the rib includes a first portion disposed upstream of a horizontal nozzle row on the most upstream side in the transport direction. 5. .   5. The fixing device according to claim 4, wherein the rib has a second portion disposed downstream of the horizontal nozzle row on the most downstream side in the conveyance direction of the recording sheet.   The fixing device according to claim 5, wherein the rib has a third portion that continuously extends from the first portion to the second portion and is connected to the first portion and the second portion. .   The fixing device according to claim 6, wherein the rib is inclined with respect to the transport direction. A plurality of the ribs are provided at intervals in an orthogonal direction orthogonal to the transport direction,
8. The first portion of one rib and the second portion of the other rib of two adjacent ribs in the orthogonal direction overlap with each other when viewed from the transport direction. The fixing device according to 1. The rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the second portion is the first portion in the orthogonal direction. A plurality of second ribs disposed on the other side of the
The fixing device according to claim 7, wherein the plurality of first ribs and the plurality of second ribs are alternately arranged in the orthogonal direction.   The first portion of the first rib and the first portion of the second rib are connected, and the second portion of the first rib and the second portion of the second rib are connected. The fixing device according to claim 9. The rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the second portion is the first portion in the orthogonal direction. A plurality of second ribs disposed on the other side of the
The plurality of first ribs are disposed on the one side with respect to the center in the orthogonal direction of the horizontal nozzle row,
The fixing device according to claim 7, wherein the plurality of second ribs are arranged on the other side with respect to a center of the horizontal nozzle row in the orthogonal direction.   The fixing device according to claim 11, wherein the first portion of the first rib and the first portion of the second rib that are closest to the center in the orthogonal direction of the horizontal nozzle row are connected. The rib includes a plurality of first ribs in which the second portion is disposed on one side of the first portion in an orthogonal direction orthogonal to the transport direction, and the second portion is the first portion in the orthogonal direction. A plurality of second ribs disposed on the other side of the
The plurality of first ribs are arranged on the other side with respect to the center in the orthogonal direction of the horizontal nozzle row,
The fixing device according to claim 7, wherein the plurality of second ribs are arranged on the one side with respect to a center of the horizontal nozzle row in the orthogonal direction.   The fixing device according to claim 13, wherein the second portion of the first rib closest to the center in the orthogonal direction of the horizontal nozzle row and the second portion of the second rib are connected. The plurality of nozzles have two first nozzles adjacent in an orthogonal direction orthogonal to the conveyance direction of the recording sheet,
The rib is disposed at a position shifted in the transport direction with respect to the two first nozzles,
The first end, which is the end of the rib on the first nozzle side, is disposed between the centers of the two first nozzles in the orthogonal direction. Item 3. The fixing device according to Item 2. The plurality of nozzles have two second nozzles adjacent in an orthogonal direction orthogonal to the transport direction,
The rib is disposed between the first nozzle and the second nozzle in the transport direction,
The second end, which is an end of the rib on the second nozzle side, is disposed between the centers of the two second nozzles in the orthogonal direction. Fixing device.   The fixing device according to claim 15, wherein a shortest distance between the first end portion and the first nozzle is equal to a shortest distance between the two first nozzles.   18. The plurality of nozzles are configured such that the spray amount per unit area is substantially equal at each position in an orthogonal direction orthogonal to the recording sheet conveyance direction. The fixing device according to claim 1. A plurality of nozzle rows arranged in the transport direction, the nozzle rows having a plurality of rows in the orthogonal direction;
The fixing device according to claim 18, wherein each of the plurality of nozzle rows includes the same number of nozzles.   20. The fixing device according to claim 1, wherein a pitch between two adjacent nozzles among the plurality of nozzles is 2 mm or more and less than 10 mm.   The fixing device according to claim 1, wherein the housing portion, the plurality of nozzles, and the rib are integrally formed of resin. A storage section for storing liquid;
A first electrode in contact with the liquid;
A nozzle that communicates with the storage unit and sprays liquid toward the recording sheet, the nozzle protruding along the first direction from the storage unit;
A rib that protrudes along the first direction from the housing portion, and is located farther from the housing portion in the first direction than the tip of the nozzle and protects the plurality of nozzles from the recording sheet. An image forming apparatus comprising an electrostatic spraying device having a rib.   The image forming apparatus according to claim 22, wherein the rib extends from the housing portion.   The image forming apparatus according to claim 22, further comprising a second electrode facing the plurality of nozzles.   25. The image forming apparatus according to claim 22, wherein the rib is arranged between two nozzles. Having a plurality of horizontal nozzle rows in which a plurality of nozzles are arranged in an orthogonal direction orthogonal to the recording sheet conveyance direction;
The image formation according to any one of claims 22 to 25, wherein the rib has a first portion disposed upstream of the horizontal nozzle row on the most upstream side in the transport direction. apparatus.   27. The image forming apparatus according to claim 26, wherein the rib has a second portion that is disposed downstream of the horizontal nozzle row on the most downstream side in the conveyance direction of the recording sheet.   28. The image forming apparatus according to claim 27, wherein the rib has a third portion that extends continuously from the first portion to the second portion and is connected to the first portion and the second portion. apparatus.   The image forming apparatus according to claim 28, wherein the rib is inclined with respect to the transport direction.

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