JP2014046603A - Ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording device capable of reducing an image defect due to the shortage of ink dryness of an image recorded on a recording medium.SOLUTION: An ink jet recording device 1, which has a nozzle for ink discharge, includes: a recording head 22 for recording an image on a recording medium T by ink discharged from the nozzle; a particle imparting part 70 for imparting spacer particles configured by containing a magnetic material on a surface of the recording medium T on which an image is recorded by the recording head 22; and a particle recovery part 81 for recovering the spacer particles imparted on the surface of the recording medium T by the particle imparting part 70 from the recording medium T.

Description

  The present invention relates to an ink jet recording apparatus that performs recording on a recording medium such as paper by ejecting ink from nozzles.

In general, an inkjet recording apparatus ejects ink from nozzles to record an image on a recording medium such as paper, and the recording medium on which the image is recorded is transported by a transport roller and transported by a transport roller. The recording medium is configured to be discharged from the discharge port.
In recent years, it has been desired to increase the speed of image recording in such an ink jet recording apparatus. In such an ink jet recording apparatus, when a recording medium on which an image is recorded is transported at high speed, the recording medium is transported by a transport roller in a state where ink of the image recorded on the recording medium is insufficiently dried. As a result, the ink of the image on the recording medium may adhere to the transport roller.

  Therefore, when ink adheres to the transport roller, the ink attached to the transport roller may adhere again to the recording medium, or the ink attached to the transport roller may adhere to the recording medium that is transported later. Thus, when the ink of the image recorded on the recording medium adheres to the transport roller, an image defect is likely to occur.

  In order to suppress the occurrence of image defects due to insufficient drying of the ink of the image recorded on the recording medium, in order to increase the drying speed of the image recorded on the recording medium. It is conceivable to provide a drying section or to use highly volatile ink or highly permeable ink. However, if the drying unit is provided in the ink jet recording apparatus, the configuration may be complicated or the apparatus may be enlarged. In addition, when highly volatile ink is used, there is a possibility that the image cannot be stably recorded because the ink is quickly dried after being ejected from the nozzle. In addition, when using a highly penetrating ink, it may depend on the characteristics of the recording medium and the usage environment, and the image may not be stably dried.

  On the other hand, as an ink jet recording apparatus that can suppress the occurrence of image defects due to insufficient drying of the ink of the image recorded on the recording medium, the particle size contained in the non-volatile solvent is 1 μm. There has been proposed an ink jet recording apparatus configured to interpose the above inorganic particles between a recording medium and the surface of a transport roller (see, for example, Patent Document 1). The ink jet recording apparatus described in Patent Document 1 suppresses adhesion of ink of an image recorded on a recording medium to the conveyance roller by interposing inorganic particles between the recording medium and the surface of the conveyance roller. It is supposed to be possible.

JP 2011-121929 A

However, in the ink jet recording apparatus described in Patent Document 1, a non-volatile solvent having a low surface tension is applied to the image recorded on the recording medium in a state where the ink of the image recorded on the recording medium is not sufficiently dried. Then, the ink of the image recorded on the recording medium is likely to bleed, and an image defect may occur.
Therefore, it is desirable to reduce image defects caused by insufficient drying of ink of images recorded on a recording medium.

  An object of the present invention is to provide an ink jet recording apparatus capable of reducing image defects caused by insufficient drying of ink of an image recorded on a recording medium.

  The present invention has a nozzle for discharging ink, a recording head for recording an image on a recording medium with ink discharged from the nozzle, and a magnetic material on the surface of the recording medium on which the image is recorded by the recording head. The present invention relates to an ink jet recording apparatus comprising: a particle applying unit that applies spacer particles configured to be included; and a particle recovery unit that recovers the spacer particles applied to the surface of the recording medium by the particle applying unit from the recording medium.

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet recording device which can reduce the image defect resulting from insufficient drying of the ink of the image recorded on the recording medium can be provided.

1 is a longitudinal sectional view schematically showing an outline of an ink jet recording apparatus 1 according to an embodiment of the present invention from the front side. FIG. 2 is a front view showing peripheral portions of a recording head unit 19 and a transport unit 30 in the inkjet recording apparatus 1 of the present embodiment. 2 is a plan view showing peripheral portions of a recording head unit 19, a transport unit 30, and a maintenance unit 50 in the inkjet recording apparatus 1 of the present embodiment. FIG. It is a front view which shows the state which the maintenance unit 50 moved below the inkjet recording device 1 shown in FIG. It is a figure which shows the structure of the particle | grain provision part 70 in the inkjet recording device 1 of this invention. It is a figure which shows the structure of the 1st particle collection part 81 in the inkjet recording device 1 of this invention. It is a figure which shows the structure of the particle supply part 91 and the particle cleaning part 95 in the inkjet recording device 1 of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The outline of the overall structure of the inkjet recording apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view schematically showing an outline of an ink jet recording apparatus 1 according to an embodiment of the present invention from the front side. FIG. 2 is a front view showing the periphery of the recording head unit 19 and the transport unit 30 in the inkjet recording apparatus 1 of the present embodiment. FIG. 3 is a plan view showing the periphery of the recording head unit 19, the transport unit 30, and the maintenance unit 50 in the inkjet recording apparatus 1 of the present embodiment. FIG. 4 is a front view showing a state in which the maintenance unit 50 is moved below the ink jet recording apparatus 1 shown in FIG.

As shown in FIGS. 1 to 3, the ink jet recording apparatus 1 of the present embodiment includes a recording head unit 19 having a recording unit 20, a transport unit 30, and a lifting device 40 of the transport unit 30 in the apparatus main body 2. The maintenance unit 50 is provided.
The ink jet recording apparatus 1 of the present embodiment further includes a sheet feeding cassette 3, a sheet feeding roller 4, a sheet feeding roller pair 5, a registration roller pair 6, a sheet conveyance path L, and conveyance as a plurality of conveyance rollers. The roller pair 10, the discharge roller pair 15, the discharge port 14, the paper discharge stacking unit 18, the switchback roller pair 11 as the switchback roller unit, the particle applying unit 70, and the first particles as the particle recovery unit A recovery unit 81, a second particle recovery unit 82 as a particle recovery unit, a particle supply unit 91 as a supply unit, and a particle cleaning unit 95 as a cleaning unit are provided. As will be described later, the sheet transport path L is an aggregate of a first transport path L1, a second transport path L2, a reversing transport path L3, and a return transport path Lb.

  As shown in FIGS. 1 to 3, the transport unit 30 includes a housing (not shown), a drive roller 32, a driven roller 33, a transport belt 31 spanned between the drive roller 32 and the driven roller 33, and a transport belt. A tension roller 34 that adjusts the tension of 31 and a suction unit 36 are provided. The conveyance belt 31 moves the paper T as a recording medium in the conveyance direction P. A large number of air suction through holes (not shown) are provided on the upper surfaces of the transport belt 31 and the suction unit 36, respectively.

When the driving roller 32 and the driven roller 33 are rotated counterclockwise when viewed from the front, the placement conveyance surface 31A formed on the upper surface portion of the conveyance belt 31 is in the conveyance direction P in the horizontal plane (XY plane). It is moved horizontally from one side to the other. That is, the transport direction P substantially coincides with the horizontal direction X on the placement transport surface 31 </ b> A of the transport belt 31. The suction unit 36 is disposed on the lower side (opposite side) of the placement and conveyance surface 31 </ b> A of the conveyance belt 31.
As the conveyor belt 31, a belt in which both ends are overlapped and joined to form an endless shape, a seamless belt (seamless), or the like can be used.

  As shown in FIGS. 2 and 3, at a predetermined recording time, the paper T as a recording medium is introduced and placed on the placement and conveyance surface 31 </ b> A of the conveyance belt 31 from one side in the conveyance direction P. The placement conveyance surface 31A is suctioned by a downward airflow acting on the conveyance belt 31 through a suction through hole (not shown) on the upper surface of the conveyance belt 31 and the adsorption unit 36 in accordance with the operation of the adsorption unit 36. There is power. The paper T placed on the placement conveyance surface 31A of the conveyance belt 31 is attracted to the placement conveyance surface 31A by the suction force of the downward airflow and conveyed toward the other side in the conveyance direction P. In this way, ink is ejected from the line-shaped recording head 22 of the recording unit 20 (described later) toward the paper T that is conveyed while being adsorbed to the placement and conveyance surface 31 </ b> A of the conveyance belt 31. An image or the like is recorded (printed).

  As shown in FIG. 1, the paper feed cassette 3 accommodates the paper T in a stacked state, and a transport unit 30 below one side inside the apparatus main body 2 (right side in FIG. 1 in the present embodiment). Are arranged on the upstream side in the conveying direction P. The paper feed roller 4 is disposed above the paper feed cassette 3. The paper feed roller 4 feeds the paper T toward the other side in the horizontal direction of the paper feed cassette 3 in FIG. 1 (left side in FIG. 1 in this embodiment).

  A discharge port 14 is provided on the upper side of the apparatus main body 2. The discharge port 14 discharges the paper T to the outside of the apparatus main body 2 by the discharge roller pair 15. Details of the discharge port 14 will be described later.

  The sheet conveyance path L includes a first conveyance path L1 from the paper feed cassette 3 to the recording unit 20 (described later), a second conveyance path L2 from the recording unit 20 to the discharge port 14, and from the middle of the second conveyance path L2. A reversing conveyance path L3 that branches and a return conveyance path Lb that returns the paper T that conveys the second conveyance path L2 from the downstream side to the upstream side to the first conveyance path L1 are provided.

The plurality of transport roller pairs 10 are roller pairs that transport the paper T. The plurality of transport roller pairs 10 are arranged at respective positions on the paper transport path L.
A pair of each transport roller pair 10 is provided apart from each other in the paper width direction Y. Each of the pair of transport rollers 10 sandwiches the paper T on both ends in the paper width direction Y and transports the paper T.

Each of the plurality of transport roller pairs 10 includes a driving roller and a driven roller. The drive roller contacts the surface of the paper T opposite to the surface on which the image is recorded by the recording unit 20. The driven roller contacts the surface of the paper T on which the image is recorded by the recording unit 20.
The plurality of transport roller pairs 10 transport the paper T at a transport speed (also referred to as “process speed”) of, for example, about 300 mm / s to 1000 mm / s.

Further, a merging portion Q1 is provided in the middle of the first transport path L1. In the middle of the second transport path L2, a reversing branch portion Q2 and a return branch portion Q3 are provided.
The junction Q1 is a junction where the return conveyance path Lb merges with the first conveyance path L1.
The reversing branch portion Q2 is a branching portion where the reversing transport path L3 branches from the second transport path L2 and the reversing transport path L3 joins the second transport path L2.
The return branch portion Q3 is a branch portion where the return transport path Lb branches from the second transport path L2.

  In the middle of the first transport path L1, a registration roller pair 6 and a paper leading edge detection sensor 12 for detecting the paper T are arranged. The paper T sent out from the paper feed cassette 3 reaches the registration roller pair 6 through the first transport path L1. The registration roller pair 6 corrects the oblique feeding of the paper T and feeds the paper T again. The front end portion of the paper T is detected by the paper front end detection sensor 12, and based on the detected timing, the recording unit 20 performs an ink ejection operation as described later.

  The second transport path L2 includes a lower horizontal portion L21 extending from the recording unit 20 to the other side in the substantially horizontal direction (left side in FIG. 1 in this embodiment), and a curved portion L22 from the lower horizontal portion L21. A vertical portion L23 extending upward in the substantially vertical direction; an upper horizontal portion L25 extending from the vertical portion L23 to the one side in the substantially horizontal direction (right side in FIG. 1 in this embodiment) via the curved portion L24; A discharge portion L26 extending obliquely upward from the horizontal portion L25 to the discharge port 14.

  In the lower horizontal portion L <b> 21, an upper side of a direction Z (hereinafter also referred to as “vertical direction Z”) perpendicular to a horizontal plane (XY plane) is opened in a portion where a particle applying unit 70 described later is disposed. In the upper horizontal portion L25, the lower side in the vertical direction Z is open at the portion where the first particle recovery unit 81 described later is disposed.

In the middle of the second conveyance path L2, the magnetic seal member 13, the particle applying unit 70, the plurality of conveyance roller pairs 10, and the first particle recovery unit 81 are arranged.
The magnetic seal member 13 is made of a magnetic material. The magnetic seal member 13 attracts the spacer particles having a magnetic material by a magnetic force so that the spacer particles do not move from the particle applying unit 70 (described later) to the recording unit 20 side to the recording unit 20 side. Magnetically shield the movement of spacer particles.

  The reversing conveyance path L3 branches from the reversing branch portion Q2 and extends in a substantially horizontal direction. A switchback roller pair 11 and a second particle recovery unit 82 are provided in the middle of the reversing conveyance path L3. The switchback roller pair 11 reverses the front and back of the paper T. The reverse conveyance path L3 conveys the paper T reversed by the switchback roller pair 11 toward the recording head. In the reversing conveyance path L3, the lower side in the up-down direction Z is open at a portion where a second particle recovery unit 82 described later is disposed.

  When recording images on both sides of the paper T, the return conveyance path Lb has a surface opposite to the already recorded surface (non-image recording surface) as a nozzle surface of a line recording head 22 (described later) of the recording unit 20. It is a conveyance path provided in order to oppose 221 (refer FIG. 2). According to the return conveyance path Lb, the paper T that is conveyed from the reversal branching section Q2 to the reversal conveyance path L3 and reversed upside down and then conveyed on the second conveyance path L2 is branched from the return branching section Q3. It can be conveyed to the upstream side of the registration roller pair 6 disposed on the upstream side of the recording unit 20. An image is recorded on the non-image recording surface in the recording unit 20 on the paper T which is turned upside down and conveyed on the return conveyance path Lb.

  A first switching member 16 is provided in the reversing branch portion Q2. The first switching member 16 has the conveyance direction of the paper T recorded in the recording unit 20 and conveyed from the upstream side toward the downstream side in the second conveyance path L2, in the direction toward the discharge port 14, or for reversal conveyance. Switch to the direction toward road L3. Further, the first switching member 16 switches the direction of the paper T that has been transported to the reversing transport path L3 and whose front and back are reversed by the switchback roller pair 11 to return to the second transport path L2.

  A second switching member 17 is provided in the return branch portion Q3. The second switching member 17 changes the transport direction of the paper T that transports the upper horizontal portion L25 of the second transport path L2 from the upstream side to the downstream side in the direction toward the discharge port 14 or the return transport path Lb. Switch in the direction you head.

  A discharge port 14 is formed at the downstream end of the second transport path L2. The discharge port 14 is disposed on the upper side of the apparatus main body 2. The discharge port 14 opens toward the right side (right side in FIG. 1) of the apparatus body 2. The discharge port 14 discharges the paper T conveyed through the second conveyance path L <b> 2 to the outside of the apparatus main body 2 by the discharge roller pair 15.

On the opening side of the discharge port 14, a paper discharge stacking portion 18 is formed. The paper discharge stacking unit 18 is formed on the upper surface (outer surface) of the apparatus main body 2. The paper discharge stacking portion 18 is a portion formed by the upper surface of the apparatus main body 2 being depressed downward. The bottom surface of the paper discharge stacking unit 18 constitutes a part of the top surface of the apparatus main body 2. A sheet T on which a predetermined image is recorded and discharged from the discharge port 14 is stacked and stacked on the discharge stacking unit 18.
A sheet detection sensor is disposed at a predetermined position in each conveyance path.

The particle applying unit 70 applies spacer particles including a magnetic material to the surface of the paper T on which an image is recorded by a line recording head 22 of the recording unit 20 described later. As shown in FIG. 1, the particle applying unit 70 is disposed on the downstream side of the recording unit 20 in the transport direction P of the paper T. The particle | grain provision part 70 is arrange | positioned in the lower horizontal part L21 of the 2nd conveyance path L2.
As shown in FIG. 3, two particle imparting units 70 are provided apart from each other in the paper width direction Y.

The first particle collecting unit 81 and the second particle collecting unit 82 collect the spacer particles applied to the surface of the paper T by the particle applying unit 70 from the paper. The first particle recovery unit 81 and the second particle recovery unit 82 are arranged on the downstream side of the particle applying unit 70 in the transport direction P of the paper T. The first particle recovery unit 81 is disposed in the upper horizontal portion L25 of the second transport path L2. The second particle recovery unit 82 is disposed on the second conveyance path L2 side of the reversal conveyance path L3.
Further, the first particle recovery unit 81 and the second particle recovery unit 82 are disposed above the particle applying unit 70 in the vertical direction Z.

The particle feeding unit 91 sends (feeds) the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 toward the particle applying unit 70.
As shown in FIG. 1, the particle feeding unit 91 includes a first feeding path 911 extending from the first particle collecting unit 81 to the lower side in the vertical direction Z, and a lower side in the vertical direction Z from the second particle collecting unit 82. A second feeding path 912 extending in the vertical direction, a feeding merging section 915 where the first feeding path 911 and the second feeding path 912 merge, and a third feeding extending from the feeding merging section 915 downward in the vertical direction Z. And a supply path 913.

The particle cleaning unit 95 is provided in the middle of the third feeding path 913. The particle cleaning unit 95 can remove the ink attached to the spacer particles by applying air to the spacer particles passing through the third feeding path 913.
Details of the particle applying unit 70, the first particle collecting unit 81, the second particle collecting unit 82, the particle feeding unit 91, and the particle cleaning unit 95 will be described later.

As shown in FIGS. 1 to 3, the recording unit 20 includes a line-shaped recording head 22 corresponding to four colors and a rectangular and plate-shaped head frame 21. The line recording heads 22 corresponding to the four colors are a black line recording head 22K, a cyan line recording head 22C, a magenta line recording head 22M, and a yellow line recording head 22Y. . These four color line-shaped recording heads 22K, 22C, 22M and 22Y extend long along the paper width direction (orthogonal direction) Y orthogonal to the transport direction P (horizontal direction X).
In this embodiment, in each of the four color line recording heads 22K, 22C, 22M and 22Y, three recording heads per one color line recording head are arranged in a zigzag pattern along the sheet width direction Y. ing. Note that “line-shaped recording head” is also simply referred to as “recording head” unless there is a particular need for distinction.

The four color line-shaped recording heads 22K, 22C, 22M and 22Y are arranged in order from the upstream side to the downstream side in the transport direction P along the transport direction P of the transport belt 31. The head frame 21 is attached by arranging the four color line-shaped recording heads 22K, 22C, 22M and 22Y in the order of arrangement described above.
In the present embodiment, the four color linear recording heads 22K, 22C, 22M and 22Y and the head frame 21 are unitized. A unit in which the four color line-shaped recording heads 22K, 22C, 22M and 22Y and the head frame 21 are integrally provided is referred to as a recording head unit 19. The recording head unit 19 is fixed to the apparatus main body 2.

  As shown in FIG. 1, below the transport unit 30, four ink tanks 23K, 23C, 23M, and 23Y are arranged corresponding to the four color line-shaped recording heads 22K, 22C, 22M, and 22Y, respectively. ing. The four color inks are supplied from the four ink tanks 23K, 23C, 23M, and 23Y to the corresponding line-shaped recording heads 22K, 22C, 22M, and 22Y through supply tubes (not shown).

  In the following description, except for the case where the configuration of the characteristic portion described later is described, the identification of the four color line recording heads 22K, 22C, 22M and 22Y and the four ink tanks 23K, 23C, 23M and 23Y is performed. The symbols “K”, “C”, “M”, and “Y” are omitted, and are simply described as “(line) recording head 22” and “ink tank 23”. The same applies to “cap 51”, “cap receiving portion 61”, “wiper member 62”, “wiper case 63”, and the like, which will be described later.

  Each line-shaped recording head 22 of the recording unit 20 is mounted on the mounting / conveying surface 31A of the conveying belt 31 based on image data information (for example, characters, figures, patterns) received from an external computer (not shown). Four color inks are ejected toward the placed paper T. The ink of this embodiment is a water-based ink. Each line-shaped recording head 22 is fixed to the apparatus main body 2 together with the head frame 21. Then, along with the rotational movement of the conveyor belt 31, four color inks are sequentially ejected from each line-like recording head 22 at a predetermined timing. As a result, four color inks of black, cyan, magenta, and yellow are superimposed on the paper T, and a color ink image is printed (recorded).

  As an ink discharge method from the recording head 22, for example, a piezo method in which ink is pushed out using a piezo element (not shown), or bubbles are generated by a heating element (not shown), and ink is discharged by applying pressure. Various discharge methods such as a thermal ink jet method can be employed.

  As shown in FIG. 1, the lifting device 40 of the transport unit 30 is disposed below the transport unit 30. The lifting device 40 moves the transport unit 30 up and down (moves) in the vertical direction Z with respect to the recording head 22. By the movement of the transport unit 30 in the vertical direction Z by the lifting device 40, the placement transport surface 31 </ b> A of the transport belt 31 can be relatively approached or separated from the nozzle surface 221 (see FIG. 2) of the recording head 22. It is configured. On the nozzle surface 221, ink discharge nozzles are formed. As a result, the transport unit 30 approaches the recording head 22 shown in FIG. 2 and is separated from the recording position (printing position) for recording an image on the paper T by the ink protruding from the nozzles and the recording head 22 shown in FIG. It is configured to be movable to a separated position. The transport unit 30 is moved in the vertical direction Z by the lifting device 40 when the nozzles of the recording head 22 are not ejecting ink.

  As shown in FIG. 1, the lifting device 40 includes two eccentric cams 41 disposed on the upstream side and the downstream side in the transport direction P below the transport belt 31. A total of four eccentric cams 41 are provided, two on each of the front side and the back side of the transport unit 30. The eccentric circumferential surface of the eccentric cam 41 approaches the outer bottom surface of the transport unit 30 from below. As shown in FIG. 1, each eccentric cam 41 includes a shaft portion 42 that extends in the paper width direction Y, and is configured by a cam having a rotational axis that is unevenly distributed. The eccentric cam 41 is rotated around the shaft portion 42 via a motor (not shown). The eccentric cam 41 includes a plurality of bearings 43 at the peripheral edge thereof. A part of the peripheral surface of the bearing 43 protrudes outward from the peripheral surface of the eccentric cam 41.

  The bearing 43 is rotatable about an axis parallel to the rotation axis of the eccentric cam 41. The bearings 43 are sequentially arranged from the distal end side of the eccentric cam 41 toward the rotation axis side. In a normal printing state, as shown in FIG. 1, the bearing 43 farthest from the shaft portion 42 contacts the outer bottom surface of the transport unit 30 from below. Thereby, the conveyance unit 30 is moved upward to the highest position shown in FIG.

From this state, the eccentric cam 41 on the upstream side in the transport direction P is rotated counterclockwise in front view, and the eccentric cam 41 on the downstream side in the transport direction P is rotated clockwise in front view. Accordingly, the plurality of bearings 43 sequentially contact the outer bottom surface of the transport unit 30 in order of the bearing 43 farthest from the shaft portion 42 to the bearing 43 closest to the shaft portion 42. Therefore, the transport unit 30 can be lowered.
The plurality of bearings 43 are arranged at intervals such that when the eccentric cam 41 rotates, the two bearings 43 adjacent in the peripheral direction simultaneously have a period of contact with the outer bottom surface of the transport unit 30.

  By rotating the eccentric cam 41 of the elevating device 40 and lowering the conveyance unit 30, the placement conveyance surface 31 </ b> A of the conveyance belt 31 in the conveyance unit 30 faces downward with respect to the recording head 22 as shown in FIG. 4. Spaced apart. As a result, the maintenance unit 50 is detached from the recording head 22. In the state where the maintenance unit 50 is detached from the recording head 22, ink is ejected from an ink ejection nozzle (not shown) of the recording head 22, thereby ejecting high viscosity ink remaining in the nozzle. Thus, it is possible to execute discharge recovery processing for eliminating ink clogging, that is, purge.

  On the other hand, as shown in FIG. 2, the conveyance unit 30 is returned to the normal recording position (printing position) by rotating the eccentric cam 41 of the elevating device 40 in the direction opposite to the above to raise the conveyance unit 30. . As a result, the maintenance unit 50 can be mounted on the nozzle surface 221 of the recording head 22.

  As shown in FIGS. 2 to 4, the maintenance unit 50 is disposed at a position on the side of the recording unit 20 (outside the sheet conveyance area) and at a lower position during image formation. Further, the maintenance unit 50 moves below the recording unit 20 as necessary. As shown in FIG. 3, the maintenance unit 50 includes a wiper member 62, a wiper case 63, a cap 51 as a cap member, a cap lower receiving portion 61, a cap base member 52, a slide mechanism 53, and not shown. And a vertical drive mechanism. The maintenance unit 50 is configured to be horizontally movable in the paper width direction Y by a slide mechanism 53 (see FIG. 3). 2 and 4, the drawing of the slide mechanism 53 of the maintenance unit 50 is omitted.

  The maintenance unit 50 is disposed above the transport unit 30 and is configured to be lifted and lowered together with the transport unit 30 by the lifting device 40. Therefore, the maintenance unit 50 can attach and detach the cap 51 to the recording head 22.

  As shown in FIG. 3, the cap 51 is arranged for each color (four colors) along the transport direction P (X), and further corresponds to the three recording heads 22 arranged in a staggered pattern in the paper width direction Y. In total, twelve are provided, three for each color. The cap 51 faces the nozzle surface 221 of the recording head 22 and covers the nozzle surface 221.

One cap lower receiving portion 61 is arranged below one cap 51 for one color corresponding to three caps 51 for one color. The four cap lower receiving portions 61 corresponding to the four colors are integrally formed to form the receiving portion unit 60.
The cap base member 52 holds the cap 51 and the receiving unit 60.

  As shown in FIG. 3, the slide mechanism 53 extends in the sheet width direction Y perpendicular to the transport direction P from the position where the recording unit 20 and the transport unit 30 are arranged toward the back side. The slide mechanism 53 includes two endless transfer belts 54 arranged at intervals in the transport direction P.

  The transfer belt 54 supports the cap base member 52 so as to straddle between the two transfer belts 54. Accordingly, as shown in FIG. 3, the slide mechanism 53 positions the cap base member 52 on the mounting position (indicated by a two-dot chain line) immediately below the recording unit 20 and on the back side of the arrangement location of the recording unit 20. It can be slid between the retracted position. That is, with the slide mechanism 53, the cap 51 can take two positions with respect to the recording head 22, that is, a mounting position below the recording head 22 and a retracted position located on the back side of the recording unit 20.

The cap 51 is attached to the recording head 22 by the maintenance unit 50. The operation will be described below.
When the cap 1 is attached to each recording head 22, the printer 1 uses the lifting device 40 (see FIG. 1) to lower the transport unit 30 from the position during normal printing, as shown in FIG. Thereby, a gap is formed between the recording unit 20 including the recording head 22 and the transport unit 30.

  Thereafter, the cap base member 52 is inserted into a gap formed between the recording head 22 of the recording unit 20 and the transport unit 30 using the slide mechanism 53. Then, the cap base member 52 is disposed below the recording head 22 and raised by a vertical drive mechanism (not shown). As a result, the cap 51 is mounted in contact with the nozzle surface 221 on the bottom surface of the recording head 22. As the vertical drive mechanism, for example, a mechanism that synchronously drives cams and the like disposed at the four corners of the cap base member 52 is used.

As shown in FIG. 3, the wiper member 62 and the wiper case 63 are arranged on one end side in the paper width direction Y of the maintenance unit 50.
The wiper member 62 cleans the nozzle surface 221 of the recording head 22. The wiper member 62 is disposed corresponding to the recording head 22. Four wiper members 62 are arranged for each of the three recording heads 22 arranged in two rows in a staggered manner in the paper width direction Y for each color (four colors). Specifically, the wiper member 62 includes, for each color (four colors), two wiper members 62 corresponding to one row of each recording head 22 and two wiper members 62 corresponding to the other row. In total, 16 are provided, four for each color.

  Each wiper member 62K, 62C, 62M, 62Y is formed in a plate shape by an elastic body. The wiper members 62K, 62C, 62M, and 62Y are erected vertically on the wiper cases 63K, 63C, 63M, and 63Y (extending in the vertical direction Z) so as to be orthogonal to the paper width direction Y. .

  The wiper members 62K, 62C, 62M, and 62Y are connected to a moving mechanism (not shown). The moving mechanism integrally moves the plurality of wiper members 62 along the paper width direction Y. As a result, the wiper members 25K, 25C, 25M, and 25Y move along the paper width direction Y, which is the direction along the nozzle surface 221 after the tips contact the respective recording heads 22K, 22C, 22M, and 22Y. As a result, the nozzle surface 221 is cleaned.

Next, with reference to FIG. 1 to FIG. 7, a configuration related to a characteristic part in the inkjet recording apparatus 1 of the present embodiment will be described in detail. The structure regarding the particle | grain provision part 70, the 1st particle | grain collection | recovery part 81, the 2nd particle | grain collection | recovery part 82, the particle | grain supply part 91, and the particle | grain cleaning part 95 is demonstrated in detail.
FIG. 5 is a diagram showing the configuration of the particle applying unit 70 in the inkjet recording apparatus 1 of the present invention. FIG. 6 is a diagram showing the configuration of the first particle recovery unit 81 in the inkjet recording apparatus 1 of the present invention. FIG. 7 is a diagram showing a configuration of the particle cleaning unit 95 of the particle feeding unit 91 in the inkjet recording apparatus 1 of the present invention.

  As shown in FIG. 1, the particle applying unit 70 is disposed on the downstream side of the recording unit 20 in the transport direction P of the paper T. The particle | grain provision part 70 is arrange | positioned in the middle of the lower horizontal part L21 of the 2nd conveyance path L2. The particle | grain provision part 70 is arrange | positioned at the upper side of the lower horizontal part L21 of the 2nd conveyance path L2.

  The particle applying unit 70 causes the spacer particles to fall on the surface of the paper T from the upper side in the vertical direction Z with respect to the paper T conveyed on the lower horizontal portion L21 of the second conveyance path L2. Thereby, the particle applying unit 70 applies spacer particles including the magnetic material to the surface of the paper T on which the image is recorded by the recording head 22.

  As shown in FIG. 3, the particle applying unit 70 has both ends in the paper width direction Y corresponding to the positions where the conveyance roller pair 10 is provided on the upper side in the vertical direction Z of the loading and conveying surface 31 </ b> A of the conveying belt 31. Two are provided apart from each other. The particle applying unit 70 is configured to apply spacer particles to an area where the conveyance roller pair 10 contacts on the surface on which the image of the paper T is recorded after the recording head 22 records the image on the paper T. . When the particle applying unit 70 applies spacer particles to the paper T, the paper T on which an image is recorded is prevented from coming into contact with the transport roller pair 10.

  The spacer particles include a magnetic material and a resin material. The magnetic material for the spacer particles is not particularly limited, and examples thereof include ferrite, magnetite, and iron powder. As the resin material of the spacer particles, it is preferable that the ink attached to the spacer particles is easily separated from the spacer particles from the viewpoint of ensuring the cleaning property of the ink attached to the spacer particles, and the contact angle with water is 90 degrees or more. Preferably there is. Examples of the resin material for the spacer particles include silicon-based resins and fluorine-based resins.

The weight of the spacer particle is a weight that falls by its own weight due to gravity.
The shape of the spacer particles is preferably closer to a true sphere from the viewpoints of cleanability and fluidity.
As for the diameter of the spacer particles, if the diameter of the spacer particles is too small, the effect as a spacer is small, and the image tends to adhere to the conveying roller pair 10. Further, when the spacer particles have a large diameter, the area of point contact with the paper T becomes large, so that the image recorded on the paper T is easily peeled off. From such a viewpoint, the diameter of the spacer particles is preferably about 70 μm or more and 150 μm or less, and more preferably about 90 μm or more and 130 μm or less.

The particle applying unit 70 applies, for example, spacer particles having a density of 1800 / cm ² or more and 5000 / cm ² or less to the surface of the paper T. When the density for applying the spacer particles is low, the effect as a spacer tends to be lost with respect to the unevenness of the paper T and the curvature of the conveying roller pair 10. In addition, when the density for applying the spacer particles is high, the voids formed between the spacer particles hold the ink and easily peel off the image recorded on the paper T.

The saturation magnetization value of the spacer particles is not particularly limited, but is preferably 35 emu / g or more and 50 emu / g or less, for example.
The volume resistivity of the spacer particles is not particularly limited, but is preferably 108 Ω · cm or more and 1012 Ω · cm or less, for example.

Next, the configuration of the particle applying unit 70 will be described in more detail.
In the present embodiment, the configuration of the two particle applying units 70 that are spaced apart from each other in the paper width direction Y is the same, and therefore one particle applying unit 70 in the paper width direction Y will be described.
As shown in FIG. 5, the particle application unit 70 includes an application side accommodating housing 73, an application roller unit 74, a first application side scraping blade 75 as a scraping member, and a second application side scraping blade 76. .

  Spacer particles configured to contain a magnetic material are accommodated inside the application-side accommodating housing 73. An application side opening 731 that opens toward the left side in the horizontal direction X is formed below the application side housing 73.

  An introduction opening 732 is formed in the upper part of the application side housing 73. A particle feed unit 91 (see FIG. 1) is connected to the introduction opening 732. Since the particle feeding unit 91 is connected to the introduction opening 732, the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 described later are supplied to the particle via the introduction opening 732. It is introduced from the portion 91 into the inside of the application side housing 73. The application side housing 73 is made of, for example, a synthetic resin material.

  When viewed in the paper width direction Y, the application roller unit 74 is disposed so as to block a portion on the upper side of the application side opening 731 of the application side housing 73. When viewed in the paper width direction Y, the application roller portion 74 is arranged in the interior of the application-side housing 73 with a substantially half on the upstream side in the transport direction P of the paper T.

  The application roller unit 74 includes an application side magnetic member 742 and an application side rotation sleeve 741.

  The application side rotation sleeve 741 is disposed outside the application side magnetic member 742. The application side rotation sleeve 741 is formed in a cylindrical shape. The application-side rotation sleeve 741 forms the surface of the application roller unit 74.

  The application side rotation sleeve 741 is rotatable in the direction of arrow A about the first rotation axis J1. The application side rotation sleeve 741 has a predetermined width corresponding to the length of the conveyance roller pair 10 in the sheet width direction Y in the axial direction of the first rotation axis J1.

  The application-side rotating sleeve 741 rotates with spacer particles attached to the surface by the magnetic force of the application-side magnetic member 742 disposed inside. The application-side rotating sleeve 741 is configured to pump the spacer particles accommodated (introduced) in the application-side accommodation housing 73 and attach the spacer particles to the surface. The application side rotation sleeve 741 is rotationally driven by an application side rotation sleeve drive unit (not shown). The spacer particles adhering to the surface of the application side rotation sleeve 741 are dropped onto the surface of the paper T by a first application side scraping blade 75 described later.

The amount of spacer particles dropped from the surface of the application-side rotation sleeve 741 onto the surface of the paper T is the distance between the tip of the first application-side scraping blade 75 described later and the application-side rotation sleeve 741, or the second described later. It can be appropriately adjusted according to the distance between the tip of the application side scraping blade 76 and the application side rotation sleeve 741, the rotation speed of the application side rotation sleeve 741, and the like. For example, the rotation speed of the application-side rotation sleeve 741 can be set to a circumferential speed that is about half of the conveyance speed (process speed) in the conveyance roller pair 10.
Examples of the material of the application-side rotation sleeve 741 include nonmagnetic materials such as aluminum.

  As shown in FIG. 5, the application-side magnetic member 742 is fixed to a predetermined position inside the application-side rotation sleeve 741 without rotating. The application-side magnetic member 742 attracts the spacer particles accommodated in the application-side accommodation housing 73 by a magnetic force and adheres the spacer particles to the surface of the application-side rotation sleeve 741.

In the present embodiment, the application-side magnetic member 742 is disposed so as to extend from the center side of the first rotation axis J1 of the application-side rotation sleeve 741 to the lower side in the up-down direction Z. It arrange | positions so that a south pole may be located in the front-end | tip. Moreover, the magnitude | size of the magnetic force of the S pole of the provision side magnetic member 742 is 30 mT or more and 40 mT or less, for example.
Further, the application-side magnetic member 742 has a predetermined width corresponding to the length of the conveyance roller pair 10 in the paper width direction Y in the axial direction of the first rotation axis J1.

The first application side scraping blade 75 is disposed on the downstream side of the application side magnetic member 742 in the rotation direction A of the application side rotation sleeve 741.
The first application-side scraping blade 75 is disposed so that the tip portion faces the surface of the application-side rotation sleeve 741 in a state where the tip portion is close to the surface of the application-side rotation sleeve 741. For example, in the present embodiment, the tip of the first application side scraping blade 75 is separated from the surface of the application side rotation sleeve 741 by about 0.5 mm. The first application side scraping blade 75 scrapes off the spacer particles adhering to the surface of the application side rotating sleeve 741 by the magnetic force of the application side magnetic member 742 and drops the spacer particles onto the surface of the paper T.

  The second application side scraping blade 76 is disposed downstream of the first application side scraping blade 75 in the rotation direction A of the application side rotating sleeve 741. The second application-side scraping blade 76 is disposed so that the tip portion faces the surface of the application-side rotation sleeve 741 in a state where the tip portion is close to the surface of the application-side rotation sleeve 741.

  The second application-side scraping blade 76 removes the spacer particles adhering to the surface of the application-side rotating sleeve 741 after the spacer particles are scraped off from the surface of the application-side rotating sleeve 741 by the first application-side scraping blade 75. The amount of spacer particles applied to the paper T is adjusted by scraping.

  As shown in FIG. 1, the first particle recovery unit 81 and the second particle recovery unit 82 are arranged on the downstream side of the particle applying unit 70 in the transport direction P of the paper T. The first particle recovery unit 81 and the second particle recovery unit 82 are disposed on the upper side in the vertical direction Z with respect to the particle applying unit 70.

  The first particle recovery unit 81 is disposed in the middle of the upper horizontal portion L25 of the second transport path L2. The first particle recovery unit 81 is disposed on the lower side of the upper horizontal portion L25 of the second transport path L2. The first particle recovery unit 81 recovers spacer particles adhering to the paper transported through the second transport path L2.

  The first particle recovery unit 81 recovers spacer particles attached to the surface of the paper T on which the image is recorded by the recording head 22 before the paper T is discharged to the outside of the ink jet recording apparatus 1. In addition, the first particle recovery unit 81 causes spacer particles attached to the surface of the paper T that is reversed by the switchback roller pair 11 and conveyed to the recording head 22 to adhere to the surface facing the recording head 22. Collect before being transported.

  The second particle recovery unit 82 is disposed on the reversing branch Q2 side of the reversing transport path L3. The second particle recovery unit 82 is disposed on the lower side of the reversing conveyance path L3. The second particle recovery unit 82 recovers the spacer particles attached to the paper attached to the surface on which the image is recorded by the recording head 22 in the paper T conveyed on the reversing conveyance path L3.

  In the present embodiment, the first particle recovery unit 81 and the second particle recovery unit 82 have the same configuration except for the positions where they are arranged. Therefore, in the present embodiment, in the description of the configuration of the first particle recovery unit 81 and the second particle recovery unit 82, only the configuration of the first particle recovery unit 81 will be described for the configuration other than the configuration related to the arrangement. About description of the structure of the 2nd particle recovery part 82, description of the 1st particle recovery part 81 is applied or used in description other than arrangement | positioning.

Next, the configuration of the first particle recovery unit 81 will be described in more detail.
As shown in FIG. 6, the first particle collection unit 81 includes a collection side housing 83, a collection roller unit 84, and a collection side scraping blade 85.

  In the collection-side housing 83, spacer particles including a magnetic material are collected from the surface of the paper T and stored. On the upper left side of the collection side housing 83, a collection side opening 831 that opens obliquely upward is formed.

  A lead-out opening 832 is formed in the lower part of the collection side housing 83. A particle feeding unit 91 is connected to the lead-out opening 832. Since the particle feeding unit 91 is connected to the outlet opening 832, the spacer particles collected by the first particle collecting unit 81 are transferred from the collection side housing 83 to the particle feeding unit 91 via the outlet opening 832. Derived. The collection side housing 83 is made of, for example, a synthetic resin material.

  When viewed in the paper width direction Y, the collection roller unit 84 is disposed so as to block the collection side opening 831 of the collection side housing 83. When viewed in the paper width direction Y, the collection roller portion 84 is disposed in the collection side housing 83 at a substantially half on the lower side in the vertical direction Z.

  As shown in FIG. 6, the collection roller unit 84 includes a first collection side magnetic member 842, a second collection side magnetic member 843, a third collection side magnetic member 844, and collection side magnetic members 842, 843, 844. A collection-side rotation sleeve 841 disposed outside.

  The collection-side rotation sleeve 841 is disposed outside the first collection-side magnetic member 842, the second collection-side magnetic member 843, and the third collection-side magnetic member 844. The collection side rotation sleeve 841 is formed in a cylindrical shape. The collection side rotation sleeve 841 forms the surface of the collection roller unit 84.

  The collection-side rotation sleeve 841 can rotate in the direction of arrow B around the second rotation axis J2. The collection-side rotation sleeve 841 extends over the entire range in which the paper T is disposed in the axial direction of the second rotation axis J2 (paper width direction Y). That is, the collection-side rotation sleeve 841 can collect the spacer particles from the surface of the paper T in the entire area in the paper width direction Y.

  The collection-side rotation sleeve 841 is disposed on the lower side of the upper horizontal portion L25 of the second transport path L2. The collection-side rotation sleeve 841 is arranged at a predetermined distance away from the sheet T conveyed on the upper horizontal portion L25 of the second conveyance path L2 in the portion opened on the lower side of the upper horizontal portion L25. . The collection-side rotation sleeve 841 is disposed, for example, at a position about 1 mm away from the paper T that is transported through the upper horizontal portion L25 of the second transport path L2.

The collection-side rotation sleeve 841 rotates with spacer particles attracted by the magnetic force of the collection-side magnetic members 842, 843, 844 attached to the surface. The collection-side rotation sleeve 841 is rotationally driven by a collection-side rotation sleeve drive unit (not shown).
Examples of the material of the collection-side rotation sleeve 841 include nonmagnetic materials such as aluminum.

The first collection-side magnetic member 842, the second collection-side magnetic member 843, and the third collection-side magnetic member 844 are fixed to a predetermined position inside the collection-side rotation sleeve 841 without rotating.
The first collection-side magnetic member 842 attracts the spacer particles attached to the surface of the paper T by a magnetic force, and attaches the spacer particles to the surface of the collection-side rotation sleeve 841.

  In the present embodiment, the first recovery-side magnetic member 842 is disposed so as to extend upward in the vertical direction Z from the center side of the second rotation axis J2 of the recovery-side rotation sleeve 841, as shown in FIG. It is arranged so that the south pole is located at the tip on the upper side in the vertical direction Z. The magnitude of the magnetic force of the S pole of the first recovery-side magnetic member 842 is, for example, 50 mT or more and 60 mT or less.

  The second recovery side magnetic member 843 is recovered from the first recovery side magnetic member 842 about 30 degrees downstream in the rotation direction B of the recovery side rotation sleeve 841 and from the center side of the second rotation axis J2 of the recovery side rotation sleeve 841. It arrange | positions so that it may extend to the radial direction outer side of the side rotation sleeve 841, and it arrange | positions so that the N pole may be located in the front-end | tip of the radial direction outer side of the collection | recovery side rotation sleeve 841. The magnitude of the N-pole magnetic force of the second recovery-side magnetic member 843 is, for example, not less than 40 mT and not more than 50 mT.

  The third collection-side magnetic member 844 is collected from the second collection-side magnetic member 843 about 30 degrees downstream in the rotation direction B of the collection-side rotation sleeve 841 and from the center side of the second rotation axis J2 of the collection-side rotation sleeve 841. It arrange | positions so that it may extend to the radial direction outer side of the side rotation sleeve 841, and it arrange | positions so that the N pole may be located in the front-end | tip of the radial direction outer side of the collection | recovery side rotation sleeve 841. The magnitude of the N-pole magnetic force of the third recovery-side magnetic member 844 is, for example, not less than 40 mT and not more than 50 mT.

  Since the front end of the first recovery side magnetic member 842 and the front end of the second recovery side magnetic member 843 are configured with N poles, the recovery side rotation sleeve 841 is attracted and moved by the magnetic force to the surface of the recovery side rotation sleeve 841. The spacer particles adhering to the surface of the first member are easily separated from the surface of the recovery-side rotating sleeve 841 because the magnetic force is weakened at a position between the first recovery-side magnetic member 842 and the second recovery-side magnetic member 843, and the recovery-side accommodating housing Easily falls inside 83.

  The first collection-side magnetic member 842, the second collection-side magnetic member 843, and the third collection-side magnetic member 844 are ranges in which the sheet T is arranged in the axial direction (sheet width direction Y) of the second rotation axis J2. It extends over the whole area.

The collection-side scraping blade 85 is disposed on the downstream side of the third collection-side magnetic member 844 as viewed in the rotation direction of the collection-side rotation sleeve 841, with the tip portion facing the surface of the collection-side rotation sleeve 841. .
The collection-side scraping blade 85 removes the spacer particles that have not been separated from the surface of the collection-side rotation sleeve 841 between the second collection-side magnetic member 843 and the third collection-side magnetic member 844 from the surface of the collection-side rotation sleeve 841. Can be scraped off.

As shown in FIG. 1, the particle feeding unit 91 feeds the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 toward the particle applying unit 70.
As shown in FIGS. 1 and 7, the particle feeding unit 91 includes a first feeding path 911, a second feeding path 912, and a third feeding path 913.

  The first feeding path 911 and the third feeding path 913 are feeding paths that connect the first particle collecting unit 81 and the particle applying unit 70, and spacer particles are transferred from the first particle collecting unit 81 to the particle applying unit 70. It is a supply route to send to. The second feeding path 912 and the third feeding path 913 are feeding paths that connect the second particle collecting unit 82 and the particle applying unit 70, and spacer particles are transferred from the second particle collecting unit 82 to the particle applying unit 70. It is a supply route to send to.

The first feed path 911 has an upper end connected to the first particle recovery unit 81 and extends obliquely from the first particle recovery unit 81 to the lower left side.
The second feeding path 912 has an upper end connected to the second particle recovery unit 82 and extends obliquely downward to the right from the second particle recovery unit 82. The lower end portion of the second feeding path 912 is connected to the lower end portion of the first feeding path 911 at the feeding / merging portion 915.
The third feeding path 913 has an upper end connected to the feeding / merging unit 915, extends downward from the feeding / merging unit 915, and a lower end connected to the particle applying unit 70.

  The first feeding path 911, the second feeding path 912, and the third feeding path 913 have a function of removing ink attached to the spacer particles. Specifically, ink may adhere to the spacer particles collected by the first particle collection unit 81. In this case, the ink adhered to the spacer particles is dried and solidified while being fed through the particle feeding unit 91. Then, the spacer particles to which the ink has adhered fall and pass through the first feeding path 911, the second feeding path 912, or the third feeding path 913, so that the spacer particles rub against each other and adhere to the spacer particles. The ink that has been removed can be separated from the spacer particles.

  The spacer particles and ink separated by dropping through the first feeding path 911, the second feeding path 912, and the third feeding path 913 are introduced into the particle applying unit 70. The spacer particles are configured to include a magnetic material. Therefore, the particle applying unit 70 can apply only spacer particles to the surface of the application-side rotation sleeve 741 by the application-side magnetic member 742 and apply only spacer particles to the paper T.

  As shown in FIG. 1, the particle cleaning unit 95 is provided in the third feeding path 913 of the particle feeding unit 91. The particle cleaning unit 95 removes ink attached to the spacer particles. As shown in FIG. 7, the particle cleaning unit 95 includes a cleaning passage 951, a blower fan 952 as a fan, a fan side filter 953, and a discharge side filter 954.

  The cleaning passage 951 is formed so as to extend a predetermined length in the substantially horizontal direction X, and is disposed so as to cross the third feeding path 913. On one end portion side (left side in FIG. 7) of the cleaning passage 951, an inclined portion 951A that is inclined downward is formed.

  The blower fan 952 and the fan-side filter 953 are disposed at the other end of the cleaning passage 951 opposite to the inclined portion 951A (right side in FIG. 7). The blower fan 952 is disposed on the other end side (right side in FIG. 7) of the cleaning passage 951 with respect to the fan-side filter 953. The fan-side filter 953 removes foreign matters mixed in the wind sent from the blower fan 952 before the wind is applied to the spacer particles.

  The blower fan 952 sends the wind along the cleaning passage 951 through the fan-side filter 953. The wind sent out along the cleaning passage 951 by the blower fan 952 hits the spacer particles falling through the third supply path 913. Here, as described above, ink may adhere to the spacer particles that fall through the third feeding path 913. The ink attached to the spacer particles may not be completely separated only by rubbing the spacer particles.

  In such a case, when the ink is attached to the spacer particles, the air blowing fan 952 sends out the wind, so that the ink attached to the spacer particles is blown off by the air blown to the air blowing fan 952 and separated. Then, the cleaning passage 951 moves to the inclined portion 951A side. In this way, the blower fan 952 can apply air to the spacer particles to remove the ink attached to the spacer particles.

  The discharge filter 954 is disposed at one end of the cleaning passage 951 on the inclined portion 951A side. The discharge filter 954 captures foreign matter such as ink that is blown by the wind sent from the blower fan 952.

Next, the operation of the ink jet recording apparatus 1 of the present embodiment will be described with reference to FIG.
First, a case where one-side recording is performed on the paper T stored in the paper feed cassette 3 will be described.
The paper T accommodated in the paper feed cassette 3 is sent out to the first transport path L1 by the paper feed roller 4 and the paper feed roller pair 5, and then transported to the registration roller pair 6 through the junction portion Q1.
In the registration roller pair 6, skew correction of the paper T and timing adjustment with an image to be recorded are performed.

The paper T discharged from the registration roller pair 6 is transported on the transport belt 31 via the first transport path L 1 and transported to the recording head 22. Then, an image is recorded on the paper T by the recording head 22.
Thereafter, the paper T is transported to the downstream side of the recording head 22 in the transport direction P by the transport belt 31, and is sent out to the second transport path L2.

  Next, the sheet T passes below the particle applying unit 70 in the lower horizontal portion L21 of the second transport path L2. The particle applying unit 70 applies spacer particles to the paper T on which an image is recorded by the recording head 22. The spacer particles are applied to the portion of the paper T where the transport roller pair 10 contacts.

  Specifically, the spacer particles accommodated inside the application side housing 73 (see FIG. 5) are attracted by the magnetic force of the application side magnetic member 742 (see FIG. 5), and from the inside of the application side housing 73. It is pumped up and adheres to the surface of the application side rotation sleeve 741 (see FIG. 5).

  When the application-side rotation sleeve 741 rotates in this state, the spacer particles are conveyed in the rotation direction A of the application-side rotation sleeve 741 in a state of adhering to the surface of the application-side rotation sleeve 741. Then, the spacer particles are dropped on the surface of the paper T by the spacer particles being scraped off from the surface of the application side rotating sleeve 741 by the first application side scraping blade 75 and the second application side scraping blade 76. As a result, spacer particles are applied (attached) to the portion of the surface of the paper T where the conveyance roller pair 10 contacts.

  Continuously, the paper T to which the spacer particles are applied is conveyed toward the first particle recovery unit 81 via the second conveyance path L2. Here, for example, the paper T is transported at a transport speed (process speed) of 800 mm / s.

  Here, the paper T is being transported in a state where spacer particles are attached to a region where the transport roller pair 10 contacts. Therefore, the spacer particles function as a spacer material between the paper T and the transport roller pair 10, and the paper T is transported in a state where the surface on which the image is recorded and the transport roller pair 10 are hardly in contact with each other. Thereby, the ink of the image recorded on the paper T is reduced from adhering to the transport roller pair 10.

  Then, the paper T is transported through the second transport path L2, and passes above the first particle recovery unit 81 in the upper horizontal portion L25 of the second transport path L2. The first particle recovery unit 81 recovers spacer particles attached to the paper T.

  Specifically, the spacer particles adhering to the paper T are attracted by the magnetic force of the first recovery side magnetic member 842 (see FIG. 6) of the first particle recovery unit 81, and the recovery side rotation sleeve 841 (see FIG. 6). Adhere to the surface. The spacer particles adhering to the surface of the collection-side rotation sleeve 841 are rotated by the collection-side rotation sleeve 841 in the rotation direction B, whereby the second collection-side magnetic member 843 (see FIG. 6) and the third collection-side magnetic member 844 ( It falls from the surface of the collection | recovery side rotation sleeve 841 in the part between (refer FIG. 6). Since the tip of the second recovery-side magnetic member 843 and the tip of the third recovery-side magnetic member 844 are composed of N poles, the position between the second recovery-side magnetic member 843 and the third recovery-side magnetic member 844 This is because the magnetic force is weakened.

Further, the tip of the recovery side scraping blade 85 is opposed to a portion between the second recovery side magnetic member 843 and the third recovery side magnetic member 844 on the surface of the recovery side rotation sleeve 841. Therefore, the collection-side scraping blade 85 scrapes off the spacer particles from the surface of the collection-side rotating sleeve 841.
By being configured as described above, the spacer particles scraped off from the surface of the collection side rotation sleeve 841 are dropped and collected in the collection side housing 83.

  The spacer particles recovered from the paper T in the recovery side housing 83 by the first particle recovery unit 81 are fed from the first particle recovery unit 81 to the particle applying unit 70 via the particle feeding unit 91. The The particle feeding unit 91 extends from the upper side in the vertical direction Z to the lower side. Therefore, the spacer particles collected in the first particle collecting unit 81 are dropped toward the particle applying unit 70 by the gravity in the particle feeding unit 91.

  At this time, the ink may adhere to the spacer particles recovered by the first particle recovery unit 81. In this case, the ink adhered to the spacer particles is dried and solidified while being fed through the particle feeding unit 911. The spacer particles to which the ink has adhered fall and pass through the first feeding path 911 and the third feeding path 913, so that the spacer particles rub against each other. Thereby, the ink adhering to the spacer particles is separated from the spacer particles and peeled off.

A particle cleaning unit 95 is provided in the middle of the particle feeding unit 91. Therefore, when the ink adheres to the spacer particles, the particle cleaning unit 95 can remove the ink adhering to the spacer particles falling from the particle feeding unit 91 from the spacer particles.
Specifically, wind is applied to the spacer particles falling from the particle feeding unit 91 by the blower fan 952. And the ventilation fan 952 blows off the ink adhering to the spacer particles. Thereby, the ink adhering to the spacer particles is removed.

  Subsequently, the spacer particles from which the ink has been removed are fed to the particle applying unit 70 via the particle feeding unit 91. The spacer particles are accommodated inside the application side accommodation housing 73. The spacer particles accommodated in the application side accommodation housing 73 are pumped up from the inside of the application side accommodation housing 73 and reused when the spacer particles are applied to the paper T by the particle application unit 70.

Thereafter, the paper T from which the spacer particles have been recovered by the first particle recovery unit 81 is transported to the discharge port 14 through the second transport path L2, and is discharged from the discharge port 14 to the paper discharge stacking unit 18 by the discharge roller pair 15. .
In this way, single-sided recording of the paper T stored in the paper feed cassette 3 is completed.

Next, the operation of the inkjet recording apparatus 1 when performing duplex recording will be described.
In the case of single-sided recording, as described above, the paper T on which single-sided recording has been performed is discharged from the discharge port 14 to the paper discharge stacking unit 18 to complete the recording operation.
On the other hand, when performing double-sided recording, the sheet T on which single-sided recording has been performed is introduced into the reverse conveyance path L3 from the second conveyance path L2 and is reversed in the state where it is reversed from the time of single-sided recording. Returned to the transport path L2. Then, the paper T that has been turned upside down is transported through the second transport path L2, and is transported again to the recording head 22 via the return transport path Lb. In this way, after an image is recorded on one side of the paper T by the recording head 22, the paper T is turned upside down, and an image is recorded on the other side opposite to the one side by the recording head 22. As a result, double-sided recording is performed.

  Specifically, in the case of double-sided recording, the paper T on which one side is recorded by the recording head 22 has spacer particles on one side of the paper T by the particle applying unit 70 on the downstream side of the recording head 22. After the application, the second conveyance path L2 is conveyed. The transport direction of the paper T is switched to the reverse transport path L3 by the first switching member 16 in the reversal branch portion Q2.

  Thereafter, the paper T is conveyed to the switchback roller pair 11 via the reversing branch portion Q2. The paper T conveyed to the switchback roller pair 11 is introduced into the reversal conveyance path L3 by the switchback roller pair 11, and the reversal conveyance path L3 is opposite to the second conveyance path L2 in the reversal conveyance path L3. Is pulled into a predetermined length.

  A second particle recovery unit 82 is disposed on the second conveyance path L2 side of the reversal conveyance path L3. Therefore, the sheet T drawn into the reversing conveyance path L3 by the switchback roller pair 11 is the reversing conveyance path in a state where the one surface on which the image is recorded on the recording head 22 is opposed to the second particle recovery unit 82. In L3, the second particle recovery unit 82 passes through the upper side in the vertical direction Z.

Similar to the operation of the first particle recovery unit 81 in the case of the one-side recording operation described above, the second particle recovery unit 82 recovers the spacer particles attached to the one surface on which the image of the paper T is recorded. The spacer particles recovered by the second particle recovery unit 82 are similar to the spacer particles recovered by the first particle recovery unit 81 in the case of the above-described single-sided recording operation, and the particle supply unit 91 (second supply path). 912) to the particle applying unit 70. The spacer particles fed through the particle feeding unit 91 (second feeding path 912) are removed by the particle cleaning unit 95.
In addition, about the detailed description of operation | movement of the 2nd particle recovery part 82, the 2nd particle supply part 92, and the particle cleaning part 95, the 1st particle recovery part 81 in the above-mentioned single-sided recording, the 2nd particle supply part 92 and the operation of the particle cleaning unit 95, the description in the case of single-sided recording is cited and the description is omitted.

  Subsequently, the sheet T rotates in the direction opposite to the direction in which the switchback roller pair 11 pulls in the sheet T, so that the reverse side is reversed and the reversing conveyance path L3 through the reversing branching portion Q2. To the second transport path L2.

  Next, the paper T on which the image is recorded on one side and the front and back are reversed is transported toward the first particle recovery unit 81 through the second transport path L2. The sheet T on which the image is recorded on one side and the front and back sides are reversed is second transported so that the other side (unrecorded surface) on which the image is not recorded on the sheet T faces the first particle recovery unit 81. It is conveyed on the path L2.

Then, when the paper T passes the upper side in the vertical direction Z of the first particle recovery unit 81, the first particle recovery unit 81 adheres to the other surface (non-recorded surface) on which the image on the paper T is not recorded. Collect the spacer particles. This is because spacer particles are not directly applied to the other side of the paper T, but spacer particles attached to the transport belt 31 or the like may adhere indirectly.
Note that the detailed description of the operations of the first particle recovery unit 81, the particle feeding unit 91, and the particle cleaning unit 95 is the same as the operation in the case of single-sided recording, and thus the description in the case of single-sided recording is cited. Thus, the description is omitted.

  Next, the paper T from which the spacer particles adhering to the unrecorded surface are collected by the first particle collecting unit 81 is conveyed through the second conveyance path L2, and the conveyance direction is returned by the second switching member 17 to the conveyance path Lb. It is switched to the direction to go to, and then merges with the first transport path L1 via the merge portion Q1.

  Further, the paper T is subjected to the correction or the adjustment by the registration roller pair 80 and is conveyed to the recording head 22 via the first conveyance path L1. The paper T is transported through the return transport path Lb so that the unrecorded surface faces the nozzle surface 221 of the recording head 22. Then, an image is recorded on the unrecorded surface of the paper T, and as a result, duplex recording is performed.

  Here, before the image is recorded by the recording head 22 on the unrecorded surface of the paper T in the double-sided recording, the spacer particles attached to the unrecorded surface of the paper T are collected by the first particle collecting unit 81. Yes. Therefore, when the unrecorded surface of the paper T faces the nozzle surface 211 of the recording head 22, the spacer particles are removed from the unrecorded surface of the paper T. Therefore, spacer particles are less likely to adhere to the nozzle surface 221 of the recording head 22 facing the unrecorded surface of the paper T. Further, the entry of spacer particles into the nozzle of the nozzle surface 221 is reduced.

Subsequently, the paper T on which images are recorded on both sides is sent out from the recording head 22 to the second transport path L2. Spacer particles are applied by the particle applying unit 70 to the other surface on which the image is recorded after the paper T being conveyed through the second conveyance path L2 is reversed. The spacer particles applied to the paper T are transported through the second transport path L2, and are collected by the first particle collecting unit 81 as in the case of single-sided recording.
The detailed description of the operations of the particle applying unit 70, the first particle recovery unit 81, the particle feeding unit 91, and the particle cleaning unit 95 is the same as the operation in the case of the above-described single-side recording. The explanation of the case is used and the explanation is omitted.

Thereafter, similarly to the above-described operation in the case of single-sided recording, the paper T from which the spacer particles have been collected by the first particle collection unit 81 is conveyed to the discharge port 14 through the second conveyance path L2, and discharged by the discharge roller pair 15. The paper is discharged from the outlet 14 to the paper discharge stacking unit 18.
In this way, the double-sided recording of the paper T stored in the paper feed cassette 3 is completed.

According to the ink jet recording apparatus 1 of the present embodiment, for example, the following effects are exhibited.
In the present embodiment, the recording head 22 that has an ink ejection nozzle and records an image on the paper T with the ink ejected from the nozzle, and the magnetic surface on the surface of the paper T on which the image is recorded by the recording head 22. A particle applying unit 70 for applying spacer particles including a material, and a first particle recovery unit 81 for recovering the spacer particles applied to the surface of the paper T by the particle applying unit 70 from the paper T are provided.

  Therefore, the particle applying unit 70 can apply spacer particles to the paper T on which an image is recorded. Thereby, even if the paper T is transported in a state where the ink of the image recorded on the paper T is insufficiently dried, the spacer particles function as a spacer material. Therefore, it is possible to reduce the ink of the image recorded on the paper T from adhering to the members such as the transport roller pair 10. Therefore, it is possible to reduce image defects caused by insufficient drying of the ink of the image recorded on the paper T.

  The first particle recovery unit 81 recovers the spacer particles applied to the surface of the paper T by the particle applying unit 70 from the paper T. Therefore, it is possible to reduce the spacer particles applied to the paper T from remaining on the paper T. Therefore, it is possible to reduce image defects due to the spacer particles remaining on the paper T and the feeling of roughness on the surface of the paper T.

  In addition, since the spacer particles include a magnetic material, the movement of the spacer particles can be easily controlled by the magnetic force of a magnetic member such as a magnet. Thereby, applying the spacer particles to the paper T and recovering the spacer particles from the paper T can be easily controlled by a magnetic member such as a magnet.

  In the present embodiment, a particle feeding unit 91 that feeds the spacer particles collected by the first particle collecting unit 81 toward the particle applying unit 70 is further provided. Therefore, the spacer particles recovered by the first particle recovery unit 81 can be reused by the particle applying unit 70. Therefore, it is possible to effectively recycle the spacer particles and reduce the replenishment of the spacer particles.

  In the present embodiment, the first particle recovery unit 81 and the second particle recovery unit 82 are disposed above the particle applying unit 70 in the up-down direction Z. Therefore, the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 fall by gravity through the particle feeding unit 91 and are sent to the particle applying unit 70. Thereby, the spacer particles can be reused with a simple configuration.

  In the present embodiment, the particle feeding unit 91 further includes a particle cleaning unit 95 that removes ink attached to the spacer particles. Therefore, the spacer particles can be reused with the ink removed from the spacer particles.

  In the present embodiment, the particle cleaning unit 95 includes a blower fan 952 that can apply air to the spacer particles to remove ink attached to the spacer particles. Therefore, ink attached to the spacer particles can be removed with a simple configuration.

  Further, in the present embodiment, the image forming apparatus further includes a conveyance roller pair 10 that conveys the paper T, and the particle imparting unit 70 uses spacer particles to record the image on the paper T after the recording head 22 records the image on the paper T. It is applied to the area where the conveying roller pair 10 contacts on the surface to be recorded.

  For this reason, the spacer particles function as a spacer material between the paper T and the transport roller pair 10. Therefore, the paper T hardly comes into contact with the transport roller pair 10. Thereby, the ink of the image recorded on the paper T is unlikely to adhere to the transport roller pair 10. Further, since it is only necessary to provide the particle applying unit 70 in an area that is in contact with only the conveying roller pair 10, the cost required for the particle applying unit 70 and the spacer particles is less than providing the particle applying unit 70 in the entire area in the paper width direction Y. Can be reduced.

  Further, the spacer particles are not applied to a wide range in the paper width direction Y by applying the spacer particles only to the region where the conveying roller pair 10 contacts. Thereby, rather than applying the spacer particles to the entire area in the paper width direction Y, it is possible to reduce image defects caused by applying the spacer particles to the paper T and the roughness of the surface of the paper T.

  In the present embodiment, the first particle recovery unit 81 and the second particle recovery unit 82 record images by the recording head 22 on the paper T before the paper T is discharged to the outside of the inkjet recording apparatus 1. Collect spacer particles adhering to the surface. Therefore, it is possible to reduce the discharge of the paper T with the spacer particles attached to the outside of the ink jet recording apparatus 1. Accordingly, it is possible to reduce the rough feeling of the surface of the paper T caused by the spacer particles remaining on the surface of the paper T.

  In the present embodiment, the switchback roller pair 11 for reversing the front and back of the paper T, and the reversing conveyance path L3 for conveying the paper T reversed by the switchback roller pair 11 toward the recording head 22 are provided. The first particle recovery unit 81 further includes spacer particles attached to the surface of the paper T that is reversed by the switchback roller pair 11 and conveyed to the recording head 22 and that is attached to the surface facing the recording head 22. Collect before being transported.

  Therefore, in the case of double-sided recording, when recording an image on the other side of the paper T on which an image is recorded on one side, spacer particles that adhere to the other side (unrecorded surface) of the paper T facing the recording head 22 The image can be recorded with the other side of the paper T facing the recording head 22 in a state where the toner is collected. Thereby, it is possible to reduce adhesion of spacer particles to the nozzle surface 221 of the recording head 22. Further, it is possible to reduce the entry of spacer particles into the nozzle of the nozzle surface 221. Therefore, ejection failure of the recording head 22 can be suppressed.

  Further, in the present embodiment, the particle applying unit 70 is disposed outside the applying side magnetic member 742 and the applying side magnetic member 742, and rotates by attaching spacer particles to the surface by the magnetic force of the applying side magnetic member 742. The application-side rotating sleeve 741 to be applied and the tip end portion of the application-side rotating sleeve 741 facing the surface of the application-side rotating sleeve 741, and the spacer particles adhering to the surface of the application-side rotating sleeve 741 are scraped off and applied to the surface of the paper T And a side scraping blade 75. Therefore, the particle applying unit 70 can apply spacer particles to the surface of the paper T by controlling the movement of the spacer particles including the magnetic material by a magnetic force with a simple configuration.

  In the present embodiment, the first particle recovery unit 81 includes a plurality of recovery-side magnetic members 842, 843, 844, and recovery-side magnetic members 842, 843 that attract the spacer particles attached to the surface of the paper T by magnetic force. A collection-side rotation sleeve 841 that is arranged outside the 844 and rotates by attaching spacer particles attracted by the magnetic force of the collection-side magnetic members 842, 843, and 844 to the surface, and a tip portion of the surface of the collection-side rotation sleeve 841 And a collection-side scraping blade 85 that scrapes and collects spacer particles attached to the surface of the collection-side rotation sleeve 841. Therefore, the first particle recovery unit 81 can recover the spacer particles on the surface of the paper T by controlling the movement of the spacer particles including the magnetic material by a magnetic force with a simple configuration.

  In the present embodiment, the spacer particles include a magnetic material and a resin material having a contact angle with water of 90 degrees or more. Since the spacer particles have a resin material having a contact angle with water of 90 degrees or more, the spacer particles are easily separated from the ink. Therefore, when ink adheres to the spacer particles, the ink can be easily separated and removed from the spacer particles by applying air to the spacer particles by the blower fan 952.

As mentioned above, although preferred embodiment of this invention was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above.
For example, in the above-described embodiment, the particle feeding unit 91 causes the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 to drop into the particle applying unit 70 by dropping the spacer particles by gravity. Although it is comprised so that it may deliver, it is not restrict | limited to this. For example, the particle feeding unit 91 feeds the spacer particles collected by the first particle collecting unit 81 and the second particle collecting unit 82 to the particle applying unit 70 by guiding the spacer particles by the magnetic force of the magnetic member. It may be configured as follows.

Further, in the above-described embodiment, the two particle applying units 70 are provided so as to be separated from each other in the paper width direction Y. However, the present invention is not limited to this, and the particle applying unit 70 is arranged in the paper width direction Y. You may form over the whole region.
In the embodiment, the ink used in the inkjet recording apparatus 1 is the water-based ink. However, the ink is not limited to this and may be an oil-based ink.

Hereinafter, the present invention will be described in more detail using examples of the present invention. However, the present invention is not limited to the following examples.
In this example, an evaluation test was performed on the following evaluation items.
<Evaluation items>
Evaluation was made regarding the size of the spacer particles, the density of spacer particles applied, the paper conveyance (process) speed, the magnetism of the spacer particles, the presence or absence of the particle cleaning unit 95, and the contact angle of the resin of the spacer particles to water.

<Evaluation method>
Evaluation was performed by the following evaluation method.
Using plain paper for copying VM-A4 (manufactured by Kyocera Document Solutions Co., Ltd.) as the paper, the paper has a length of about one turn (60 mm) of the transport roller pair 10 in the transport direction and the print amount is 1. An image was formed so as to be 06 μl / cm ² (2.6 times the reflection density 1.0).
An image was formed on the leading edge of the paper and 100,000 durable prints were made, and image evaluation was performed every 5000 sheets. In the image formed on the leading edge of the paper, the state in which the ink attached to the transport roller pair 10 is re-transferred to the paper in the next round of the transport roller pair 10, the reflection density, the number of prints that starts to recognize dirt, Evaluation was performed on the evaluation items of the number of prints that started to recognize image peeling in the print section. The reflection density was measured with a Macbeth Spectroeye spectrodensitometer. The recognition of dirt and the recognition of image peeling were evaluated by sensory evaluation (visual evaluation).

<Evaluation criteria>
X: NG is a state where a reflection density of 0.008 or more can be recognized and dirt having a diameter of about 0.3 mm or more can be recognized. If either one becomes NG up to 50,000 sheets, it is judged as x.
In addition to re-transfer, the image on the printed part may be recognized as a defective image even if it is peeled off due to contact. Therefore, when peeling of a diameter of about 0.3 mm or more is recognized by 50,000 sheets X determination.
◯: When all of the reflection density is less than 0.008, the dirt diameter is less than 0.3 mm, and the image peeling diameter is less than 0.3 mm by 50,000 sheets, it is judged as ◯.

<Evaluation standard conditions>
Evaluation standard conditions are as follows. In the following evaluation items, when there is no designation in the conditions, the following evaluation standard conditions are used.
Particle size: 110 μm
Application density: 3000 pieces / cm ²
Process speed: 800mm / s
Particle magnetism: Yes Particle cleaning process: Yes Resin type: PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) resin

<Detailed evaluation conditions and evaluation results>
(Evaluation item: Spacer particle size)
With respect to the size of the spacer particles, when the particle diameter (D ₅₀ ) is changed to 60, 70, 90, 110 (evaluation standard conditions), 130, 150, 160 μm with respect to the evaluation standard conditions, no particles ( The case of the surface of the pair of transport rollers: PFA resin layer) was evaluated.
Regarding the size of the spacer particles, the evaluation results shown in Table 1 below were obtained. Considering the evaluation results in Table 1, if the particle size is small, the spacer effect is small, and retransfer of the image onto the paper tends to occur. If the particles are too large, the point contact area increases, and this is recognized as image peeling.

(Evaluation item: Spacer particle density)
With respect to the application density of the spacer particles, the case where the particle density was changed to 1500, 1800, 3000 (evaluation standard conditions), 5000, 6000 particles / cm ² with respect to the evaluation standard conditions was evaluated.
The evaluation results in Table 2 below were obtained for the application density of the spacer particles. Considering from the evaluation results in Table 2, when the density of the spacer particles is low, the spacer effect may be lost with respect to the unevenness of the paper and the curvature of the conveying roller pair. Conversely, if the density of the spacer particles is too high, the ink is held in the gaps between the particles and the image is peeled off.

(Evaluation item: Paper transport (process) speed)
The sheet conveyance (process) speed was evaluated for the case where the process speed was changed to 250, 300, 500, 800 (standard), and 1000 mm / s with respect to the evaluation standard conditions. In the low speed range (250, 300 mm / s), the evaluation was also performed under the condition without particles.
The evaluation results shown in Table 3 below were obtained for the sheet conveyance (process) speed. Considering from the evaluation results in Table 3, a certain level of performance could be obtained even at low speed of 250 mm / s without particles. However, at 300 mm / s, the osmotic drying did not catch up. The spacer effect of the particles was not dependent on the speed.

(Evaluation item: Magnetism of spacer particles)
With respect to the magnetic properties of the spacer particles, the particles were prepared only with PFA not containing magnetic powder, and the durability test was performed with respect to the evaluation standard conditions.
As a result of evaluation of the magnetic properties of the spacer particles, there were frequent discharge failures of the recording head. When the foreign matter adhering to the nozzle surface was analyzed, it was a fluororesin.

(Evaluation item: Presence / absence of particle cleaning unit 95)
The presence / absence of the particle cleaning unit 95 was evaluated with respect to the evaluation standard condition when there was no particle cleaning unit.
The evaluation results in Table 4 below were obtained for the presence or absence of the particle cleaning unit 95. Considering the evaluation results in Table 4, image retransfer and image peeling occurred due to dirt remaining on the spacer particles, but the evaluation criteria were satisfied.

(Evaluation item: Contact angle of spacer particle resin to water)
With respect to the contact angle of spacer resin to water, the resin used is nylon (water contact angle 77 °), polyethylene (88 °), silicon (95 °), PFA (109) with respect to the evaluation standard conditions. It was evaluated for the case of changing to (standard) and PTFE (polytetrafluoroethylene) type (114 °).
The evaluation results in Table 5 below were obtained for the contact angles of the spacer particles to the resin. Considering from the evaluation results in Table 5, if the contact angle is low, the particles cannot be completely soiled, which leads to retransfer or peeling.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording apparatus, 10 ... Conveyance roller pair (conveyance roller), 11 ... Switchback roller pair (switchback part), 22 (K, C, M, Y) ... Line-shaped recording head (recording head) ), 70... Particle application unit, 75... Application side scraping blade (application side scraping member), 81... First particle recovery unit (particle recovery unit), 82. Part), 85... Collection side scraping blade (collection side scraping member), 91... Particle feeding part (feeding part), 95... Particle cleaning part (cleaning part), 741. , 742..., Giving side magnetic member, 841... Collecting side rotating sleeve, 842... First collecting side magnetic member (collecting side magnetic member), 843. ... Third recovery side magnetic member Recovery side magnetic member), 952 ...... blower fan (fan), L3 ...... reversing conveyance path, P ...... conveying direction, T ...... paper (recording medium)

Claims (13)

A recording head having a nozzle for discharging ink, and recording an image on a recording medium with ink discharged from the nozzle;
A particle applying unit that applies spacer particles including a magnetic material to the surface of a recording medium on which an image is recorded by the recording head;
An ink jet recording apparatus comprising: a particle recovery unit that recovers the spacer particles applied to the surface of the recording medium by the particle applying unit from the recording medium. The inkjet recording apparatus according to claim 1, further comprising a feeding unit that feeds the spacer particles collected by the particle collecting unit toward the particle applying unit. The inkjet recording apparatus according to claim 2, wherein the particle recovery unit is disposed above the particle applying unit. The ink jet recording apparatus according to claim 2, further comprising a cleaning unit that is provided in the feeding unit and removes ink adhering to the spacer particles. 5. The inkjet recording apparatus according to claim 4, wherein the cleaning unit includes a fan capable of removing ink attached to the spacer particles by applying air to the spacer particles. A transport roller for transporting the recording medium;
The particle applying unit applies the spacer particles to a region of the surface on which the image of the recording medium comes into contact with the transport roller after the image is recorded on the recording medium by the recording head. Any one of the inkjet recording apparatuses. The particle recovery unit recovers the spacer particles attached to a surface of the recording medium on which an image is recorded by the recording head before the recording medium is discharged to the outside of the ink jet recording apparatus. An ink jet recording apparatus according to any one of the above. A switchback unit that reverses the front and back of the recording medium;
A reversing conveyance path that conveys the recording medium reversed by the switchback unit toward the recording head,
The particle recovery unit is configured to remove the spacer particles attached to the surface of the recording medium that is reversed by the switchback unit and conveyed to the recording head, and that is attached to the surface facing the recording head, before the recording medium is conveyed to the recording head. The inkjet recording apparatus according to claim 7, wherein the inkjet recording apparatus is recovered. The particle imparting portion is disposed on the exterior of the one or more imparting side magnetic members and the imparting side magnetic member, and rotates while attaching the spacer particles to the surface by the magnetic force of the imparting side magnetic member. An application-side scraping member that scrapes off the spacer particles attached to the surface of the application-side rotation sleeve and drops onto the surface of the recording medium, and the sleeve and the tip end portion are arranged to face the surface of the application-side rotation sleeve And an ink jet recording apparatus according to claim 1. The particle recovery unit is disposed outside the recovery-side magnetic member and one or more recovery-side magnetic members that attract the spacer particles attached to the surface of the recording medium by magnetic force, and by the magnetic force of the recovery-side magnetic member. The collection-side rotating sleeve that rotates by attaching the attracted spacer particles to the surface, and the spacer that the tip portion is arranged to face the surface of the collection-side rotation sleeve and that adheres to the surface of the collection-side rotation sleeve An ink jet recording apparatus according to claim 1, further comprising a recovery side scraping member that scrapes and collects particles. The inkjet recording apparatus according to any one of claims 1 to 10, wherein the spacer particles include a magnetic material and a resin material having a contact angle with water of 90 degrees or more. The inkjet recording apparatus according to claim 1, wherein the spacer particles have a diameter of 70 μm or more and 150 μm or less. The inkjet recording apparatus according to claim 1, wherein the particle applying unit applies the spacer particles having a density of 1800 / cm ² or more and 5000 / cm ² or less to a surface of a recording medium.

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