JP2006137120A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that an effective printing speed (image formation speed) is decreased due to the necessity of superposing application of several times to carry out re-application of a setting agent to a part which runs short of the setting agent on an intermediate transfer medium after image transfer. <P>SOLUTION: A first setting agent application means 11 which applies the setting agent to the intermediate transfer medium 201, and a second setting agent application means 12 are provided. The second setting agent application means 12 is arranged at the lower stream side in an intermediate transfer body movement direction than the first setting agent application means 11 and at the upper stream side in the intermediate transfer body movement direction than a printing means 3. The second setting agent application means 12 is equipped with a re-application roller 121 which applies the setting agent to the intermediate transfer medium 201, and a re-application hair-transplanted roller 122. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus using an intermediate transfer medium and a liquid discharge head.

For example, as an image forming apparatus such as a printer, a facsimile, a copying apparatus, or a plotter, an ink jet recording apparatus including an ink jet head that ejects ink droplets is known. As such an ink jet recording apparatus, for example, as described in Patent Document 1, an ink jet head that ejects ink droplets, an intermediate transfer medium that moves with a gap with respect to the ink jet head, and the intermediate transfer Means for forming an ink image on the medium, and transferring the ink image from the intermediate transfer medium to a recording medium (also referred to as paper, recording medium, transfer material, etc.); and water absorbing powder on the intermediate transfer medium. There is a transfer type image forming apparatus provided with a coating means.
Japanese Patent Laid-Open No. 11-188858

In such a transfer-type image forming apparatus, as means for applying a water-absorbing powder (also referred to as a set agent) to the intermediate transfer medium, it is set using a blade as described in Patent Document 1 above. In addition to the one that uniformly applies the agent, the one that applies the set agent by charging as described in Patent Document 2, and the contact means is uneven as described in Patent Document 3 so as not to generate frictional force There are those that apply a set agent, and those that apply magnetic poles to an application roller and apply the set agent uniformly by slight vibration of a blade, as described in Patent Document 4.
JP 2001-10114 A JP 2001-58400 A JP 2002-292839 A

  However, in the image forming apparatus described in Patent Documents 1 to 4 described above, in the state after the image is transferred from the intermediate transfer medium to the recording medium, the set agent disappears on the intermediate transfer medium by image transfer. It is not premised that there is a part where the set agent remains without being used for image transfer and image transfer. Therefore, there is a problem that the effective printing speed (image forming speed) is lowered accordingly.

  The present invention has been made in view of the above-described problems, and is a transfer type in which an effective printing speed is improved by applying sufficient set agent by re-application of the set agent to the intermediate transfer medium after image transfer. An object is to provide an image forming apparatus.

  In order to solve the above-described problems, the image forming apparatus according to the present invention includes a first application unit and a second application unit that apply powder to the intermediate transfer medium.

  Here, it is preferable that the second application unit is disposed downstream of the first application unit in the movement direction of the intermediate transfer medium and upstream of the liquid discharge head in the movement direction of the intermediate transfer medium. In addition, it is preferable that the powder is supplied to the second coating unit from the intermediate transfer medium. Furthermore, it is preferable that the coating amount of the second coating unit is larger than the coating amount of the first coating unit on the intermediate transfer medium from which the powder has been peeled after image transfer.

  The second application means preferably includes a re-application roller that holds the powder and contacts the intermediate transfer medium, and a re-application flocking roller having flocks that contact the re-application roller and the intermediate transfer medium. .

  In this case, the re-application roller rotates while contacting the intermediate transfer medium in the forward direction, the re-application flocking roller rotates while contacting the re-application roller in the forward direction, and contacts the reverse direction of the intermediate transfer medium. It is preferable to rotate. Further, it is preferable that the re-application flocking roller is in contact with the re-application roller and the intermediate point transfer medium at the tip of flocking. Furthermore, the contact angle of the flocking at the contact point between the flocking roller and the reapplication roller is smaller than the tangential angle of the reapplying roller, and the flocking contact at the contact point between the flocking roller and the intermediate transfer medium. The angle of contact is smaller than the tangent angle of the intermediate transfer medium, or the contact angle of the flocking at the contact point between the flocking roller of the re-application flocking roller and the re-application roller is smaller than the tangential angle of the re-application roller; It is preferable that the contact angle of the flock at the contact point with the intermediate transfer medium is smaller than the tangential angle of the intermediate transfer medium.

Further, it is preferable that the application roller and the re-application flocking roller of the second application means are rotated by the movement of the intermediate transfer medium. In this case, the coefficient of friction between the re-application roller and the intermediate transfer medium is μ _TC , the coefficient of friction between the re-application flocking roller and the intermediate transfer medium is μ _NC , the weight of the re-application roller is W ₀ , and the weight of the re-application flocking roller is W ₁ , radius of the re-application roller is r ₀ , radius of the re-application flocking roller is r ₁ , the number of teeth of the gear provided on the re-application flocking roller is N _T , and the number of teeth of the gear provided on the re-application flocking roller is N _C The transport ratio η _TN obtained by (μ _NC / μ _TC ) × (W ₁ / W ₀ ) × (N _T / N _C ) × (r ₁ / r ₀ ) has a relationship of η _TN <1 Is preferably satisfied.

Alternatively, it is preferable that the application roller and the re-application flocking roller of the second application means are rotated by the movement of the intermediate transfer medium, and the re-application flocking roller is pressed against the application roller. In this case, the friction coefficient between the re-application roller and the intermediate transfer medium is μ _TC , the friction coefficient between the re-application flocking roller and the intermediate transfer medium is μ _NC , and the friction coefficient between the re-application roller and the re-application flocking roller is μ _TN , re-application When the weight of the roller is W ₀ , the weight of the re-application flocking roller is W ₁ , the radius of the re-application flocking roller is r ₀ , the radius of the re-application flocking roller is r ₁ , and the pressing force is P (μ _NC / μ _TC ) × (W ₁ / W ₀ ) × (r ₁ / r ₀ ), the transport ratio η _TN satisfies the relationship η _TN <1, and (μ _NC / μ _TN ) × (W ₁ / It is preferable that the transmission rate η _PN obtained in P) satisfies the relationship η _PN ≦ 1. Further, it is preferable that the intermediate transfer medium is inclined so that the component of the re-application flocking roller in the center direction of the re-application flocking roller is used as the pressing force.

  According to the image forming apparatus of the present invention, since the first application unit and the second application unit for applying the powder to the intermediate transfer medium are provided, the portion where the set agent does not exist after the image is transferred. In addition, a set agent that cannot be replenished by one application by the first application means can be replenished by the second application means, and printing and transfer can be effected each time the intermediate transfer medium is moved. The shooting speed can be improved.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing the overall configuration of the image forming apparatus according to the first embodiment of the present invention.
The image forming apparatus includes a first set agent application unit 11 that is a first application unit that applies powder (set agent) to an intermediate transfer medium, and a second agent that applies powder (set agent) to the intermediate transfer medium. A second set agent coating means 12, a transfer body means 2 including an intermediate transfer medium, a printing means 3 including a liquid discharge head for forming a recording liquid image on the intermediate transfer medium, and an intermediate transfer medium. Transfer means 4 for transferring the recording liquid image to the recording medium, cleaning means 5 for removing the remaining set agent on the intermediate transfer medium, paper feeding means 6 for feeding the recording medium, and feeding timing of the recording medium A registration unit 7, a discharge unit 8 for discharging a recording medium onto which the recording liquid image has been transferred, a controller 9 for controlling the entire apparatus, and the like.

  First, the 1st set agent application means 11 is demonstrated. The set agent application unit 11 is a unit that applies the powder set agent 101 to the intermediate transfer medium 201 of the transfer body unit 2. The set agent 101 is, for example, an acrylic resin, an acrylic acid / methacrylic acid copolymer resin, a methacrylic acid resin, starch, or the like, and has a particle size of about 0.5 to 20 μm.

  The set agent application means 11 is a supply stirring roller 103, an intermediate roller 104, an application roller 105, an application roller 105, and an application roller 105 and a front stage of the application roller 105 as application means for applying the set agent 101 in the casing 102. A leveling roller 106 is provided in contact with the intermediate roller 104 which is a roller, and each of these rollers 103 to 106 contacts and rotates in the direction indicated by the arrow.

  Further, the blade 107 for adjusting the replenishment amount of the set agent 101 and making the set agent 101 uniform on the replenishment agitator roller 13 in contact with the replenishment agitation roller 103, and the set agent application means 11 to the set agent 101. A blade 108 is attached to prevent leakage. Further, a replenishment tank 109 containing the set agent 101 is mounted on the casing 102 in a replaceable manner.

  And the rack part 110 attached to the casing 102 of this set agent application means 11 is meshed with a pinion 111 connected to a drive source such as a drive motor (not shown) attached to the main body side, and a drive motor (not shown) is connected. By rotationally driving, the entire set agent applying means 11 can be moved forward and backward in the direction of arrow A or B.

  That is, when the set agent 101 is applied, the drive motor or the like (not shown) on the main body side is rotated forward, whereby the pinion 111 is rotated forward and the entire set agent applying means 11 advances in the direction of arrow A via the rack portion 110. The application roller 105 comes into contact with the intermediate transfer medium 201 of the transfer body device 2. When the application of the set agent 101 is completed, the drive motor or the like (not shown) is reversely rotated, so that the pinion 111 is also reversely rotated and the entire set agent applying means 11 is moved backward in the direction of the arrow B via the rack portion 110. Thus, the application roller 105 is separated from the intermediate transfer medium 201.

  In addition, gears (not shown) are attached to the replenishing stirring roller 103, the intermediate roller 104, the application roller 105, and the leveling roller 106, respectively, and a driving force of a driving motor (not shown on the main body side) is transmitted. Thus, the replenishing stirring roller 103, the intermediate roller 104, and the application roller 105 rotate in the direction of the arrow, and at this time, the application roller 105 and the leveling roller 106 rotate while contacting in the opposite direction.

  Here, the replenishing stirring roller 103 and the intermediate roller 104 are formed by providing a porous body such as foamed urethane rubber on a metal core such as SUS or aluminum, and can sufficiently hold the set agent 101. it can. The application roller 105 is formed by coating the surface of a metal core such as SUS or aluminum with urethane or the like.

  Then, the intermediate roller 104 comes into contact with the replenishing agitation roller 103 in which the set agent 101 is sufficiently held and the layer thickness of the set agent 101 is made uniform by the blade 107, so that the set agent 101 is transferred from the replenishment agitation roller 103 to the intermediate roller. Then, the setting agent 101 is transferred from the intermediate roller 104 to the application roller 105 by the application roller 105 coming into contact with the intermediate roller 104. When the application roller 105 comes into contact with the intermediate transfer medium 201 of the transfer body unit 2, the set agent 101 is applied as a thin layer on the surface of the intermediate transfer medium 201.

  At this time, if the leveling roller 106 is not provided, the application state of the set agent 101 causes the powder to agglomerate with each other as the particle size of the set agent 101 becomes smaller. The result is a cohesive coating finish. Therefore, in the present embodiment, the set agent 101 aggregated on the application roller 105 by providing the leveling roller 106 is re-powdered so that the non-aggregated set agent 101 is uniformly thinned on the intermediate transfer medium 201. To make it possible to apply.

  The leveling roller 106 is configured by providing a flocking made of nylon or the like on the surface of a metal core made of metal such as SUS or aluminum, and is applied so as to bite a predetermined amount with respect to the outermost periphery of the leveling roller 106. A roller 105 is arranged, and the leveling roller 106 and the coating roller 105 rotate while contacting in the opposite direction of the arrow.

  Therefore, the flocking of the leveling roller 106 is deformed by receiving a bending force in a region from the point where the leveling roller 106 is in contact with the application roller 105, and the tip of the leveling roller 106 is in contact with the application roller 105 while standing. Then, the set agent 101 that becomes a stagnation on the application roller 105 can be stirred and disassembled at the tip (tip) of the flocked hair. By bringing the application roller 105 into contact with the intermediate transfer medium 201 in this state, a uniform and fine application state appears on the intermediate transfer medium 201.

  Further, when the amount of the set agent 101 of the first set agent applying means 11 becomes insufficient, it is replenished as needed from the replenishment tank 109. The replenishment tank 109 can be exchanged. When the set agent 101 is exhausted, the set agent empty is displayed by a set agent detecting means (not shown) and is replaced with a new replenishment tank 109 as needed.

Next, the transfer member means 2 will be described.
The intermediate transfer medium 201 is an endless belt formed of a material that easily adheres powder to the surface, such as silicone rubber, fluorine rubber, or chloroprene rubber, and a thin powder layer is formed by the application roller 105. The intermediate transfer medium 201 is stretched around three rollers 202, 203, and 204, and rotates in the direction of the arrow when the roller 204 is rotated by a drive motor (not shown).

  In addition, a marker 207 is provided on the end face of the intermediate transfer medium 201, while a position control encoder 206 that reads the marker 207 is provided. Then, based on the reading result of the position control encoder 206, the printing timing by the printing means 3 and the paper feeding timing from the paper feeding means 4 are controlled, and the timing with the set agent application means 11 is taken. The intermediate transfer medium 201 has, for example, a width direction of 215 mm and a circumferential length of 327 mm, and can record an A4 vertical size image with one rotation of the intermediate transfer medium 201.

Next, the printing means 3 will be described.
The printing unit 3 includes a head array 302 on which recording heads 301 corresponding to, for example, black (K), cyan (C), magenta (M), and yellow (Y) are mounted. The head array 302 is held by a guide shaft 303 and a guide shaft 304 that are two support shafts so that the gap with the intermediate transfer medium 201 is constant.

  Then, when the set agent 101 is applied to the intermediate transfer medium 201, the position control encoder 206 reads the marker 207 of the intermediate transfer medium 201, and the application portion moves to the position of the printing unit 3. Is driven, the recording liquid (ink) 305 is discharged from the recording head 301 to form an image (recording liquid image) on the intermediate transfer medium 201 coated with the set agent 101. This recording liquid image is a mirror image converted by the controller 9.

Next, the transfer unit 4 will be described.
The transfer unit 4 includes a transfer roller 401 that can move forward and backward with respect to the roller 203 of the transfer body unit 2. The transfer roller 401 is rotatably held at one end of an arm 403 that is swingably supported by a support shaft 402, and a tension spring 404 is interposed between the other end of the arm 403 and a fixed portion. A solenoid 405 is provided that urges the arm 403 in a direction in which the transfer roller 401 moves away from the roller 203 and pulls the arm 403 in a direction in which the transfer roller 401 abuts against the roller 203 against the urging force of the tension spring 404. .

  Then, the aqueous recording liquid 305 discharged by the printing means 3 is absorbed by the water-absorbing set agent (powder) 101 formed on the intermediate transfer medium 201 as a thin layer, and a gel having an appropriate viscosity. It becomes a state substance. The transfer roller 401 of the transfer unit 4 is usually separated from the roller 203, but when the transfer paper (recording medium) 601 is inserted to the position of the roller 203, the solenoid 402 is driven and pressed toward the roller 203. The

  At this time, the gel-like substance formed in the shape of an image comes into contact with the transfer paper 601, is pressurized, and completely transfers to the transfer paper 601. Since the intermediate transfer medium 201 is a silicon or fluorine-based elastic body, the releasability is good with respect to the gel material, and hardly remains on the intermediate transfer medium 201. When the transfer is completed, the solenoid 405 is deactivated and the transfer roller 401 is separated from the roller 203.

Next, the cleaning unit 5 will be described.
The cleaning means 5 is a cleaning roller 502 that contacts the intermediate transfer medium 201 to remove unnecessary residual set agent 101 in the casing 501 and cleaning that scrapes off the set agent 101 adhering to the surface of the cleaning roller 502. A blade 503.

  The rack portion 504 attached to the cleaning means 5 meshes with a pinion 505 connected to a drive source such as a drive motor (not shown) attached to the main body, and rotates the drive motor (not shown). The entire cleaning means 5 is advanced and retracted between a cleaning position where the cleaning roller 502 contacts the intermediate transfer medium 201 and a retracted position retracted from the cleaning position.

  That is, when the machine is not used for a long time, the set agent 101 on the intermediate transfer medium 201 may absorb the humidity in the air and increase the viscosity. Since the set agent 101 having such an increased viscosity cannot be used for image formation as it is, it is necessary to remove only the set agent 101 having an increased viscosity from the intermediate transfer medium 201 before use. Similarly, when the printed image on the intermediate transfer medium 201 is damaged due to a jam of the transfer paper 601 or when the printing is interrupted in the middle of printing, the set agent 101 printed on the intermediate transfer medium 201 is removed. It is necessary to remove from the intermediate transfer medium 201.

  Therefore, the cleaning unit 5 is provided, and if necessary, moves toward the intermediate transfer medium 201 to bring the cleaning roller 502 into contact with the intermediate transfer medium 201 to scrape off unnecessary setting agent 101. The necessary set agent 101 is scraped off by the cleaning blade 503, and the cleaning roller 301 is always kept clean.

Next, the paper feed unit 6, the registration unit 7, and the paper discharge unit 8 will be described.
The paper feed means 6 is fed with a paper feed tray 602 for stocking the transfer paper 601, a paper feed roller 603 for separating and feeding the transfer paper 601 placed on the paper feed tray 601 one by one. Feed rollers 604 and 605 for feeding the transfer paper 601 are provided. The registration unit 7 includes registration rollers 701 and 702 that register the transfer paper 601 fed from the paper feeding unit 6. The paper discharge unit 8 includes a paper discharge tray 801 that stacks transfer paper 601 on which an image has been transferred, and paper discharge rollers 802 and 803 that send transfer paper 601 onto which the image has been transferred to the paper discharge tray 801.

  Then, during or after printing, the transfer paper 601 is sent out from the paper supply unit 6 and is sent between the registration rollers 701 and 702 of the registration unit 7. The image formed on the intermediate transfer medium 201 is synchronized with the timing based on the position control encoder 206, the transfer paper 601 is sent out between the registration roller 701 and the registration roller 702, and the intermediate transfer is performed by the transfer roller 401 and the roller 203 of the transfer unit 4. The image on the medium 201 is transferred to the transfer paper 601, discharged onto the discharge tray 801 by the discharge rollers 82 and 83 of the discharge unit 8, and stocked.

Next, the second set agent applying means 12 will be described with reference to FIG.
First, when the second set agent application unit 12 is not provided, the application is performed when the application is repeated with the set agent adhesion amount V per unit area of the application roller 105 of the first set agent application unit 11 as a parameter. An example of the number of times and the measurement result of the coating amount m of the set agent 101 per unit area on the intermediate transfer medium 201 is shown in FIG.

From the results in FIG. 2, when the setting agent deposition amount V is smaller adhesion amount V ₁ of the application roller 105 does not enter into the optimum coating weight range the number of applications is even more than 8 times, when receiving the ink droplets 305 Therefore, the set agent adhesion amount V of the application roller 105 is not preferable.

Further, when the setting agent deposition amount V is greater adhesion amount V ₃ is reached the optimum coating weight range in the coating times once, too much coating amount in the number of applications of the above four times, the image on the transfer paper 601 It is not preferable because the powder set agent 101 adheres to the surface of the transferred image when it is transferred and causes image deterioration.

In contrast, when the setting agent deposition amount V of moderate adhesion amount V ₂ enters the optimum coating weight range in the coating times 3 times, can be repeatedly applied the number of times to maintain the optimum coating weight range be increased .

Here, if you set the setting agent deposition amount V in a suitable amount V _2, when the image on the intermediate transfer medium 201 is transferred onto the transfer sheet 601, as shown in FIG. 3 (a), the image which the image is transferred In the transfer portion PG portion, the set agent 101 disappears (no longer exists) on the intermediate transfer medium 201, and the non-image portion NG portion remains as it is.

  Therefore, each time the image transfer portion PG of the intermediate transfer medium 201 passes through the portion that comes into contact with the application roller 105, as shown in FIGS. 3B to 3E, the amount of the set agent 101 applied to the image transfer portion PG. (In the figure, the density in the figure is increased every time the set agent application amount increases.) By passing three rotations, the application amount m of the set agent 101 in the image transfer portion PG Reaches the optimum application amount necessary for transfer, and is ready for image formation and transfer, and thereafter maintains the optimum application amount range. On the other hand, the non-image area NG is in a state where the application amount m is maintained in the optimum application amount range by the remaining set agent 101 and image formation and transfer are possible.

  However, the non-image portion NG is maintained in a state where image formation and transfer can be performed after image transfer as described above. However, since the image transfer portion PG needs to apply the set agent three times by the application roller 105, The transfer medium can be transferred only once in three rotations at the maximum speed, and the effective printing speed of image output is reduced to 1/3 as compared with the original conveyance speed of the intermediate transfer medium 201.

  Therefore, in order to prevent this effective reduction in the printing speed, the present invention is provided with the second set agent application means 12. That is, as shown in FIG. 1, it is also a recoating device downstream of the first set agent coating device 11 in the intermediate transfer medium moving direction and upstream of the printing means 3 in the intermediate transfer medium moving direction (circumferential direction). Second set agent application means 12 is arranged. In other words, the second set agent application unit 12 is arranged between the first set agent application unit 11 and the printing unit 3 (the recording head 301 which is a liquid ejection head).

The second set agent application unit 12 includes a reapplication roller 121 disposed on the upstream side in the movement direction of the intermediate transfer medium 201 and a reapplication flocking roller 122 disposed on the downstream side. As shown in FIG. 5, the re-application roller 121 can sufficiently hold the set agent 101 by forming a porous body 131 such as urethane foam rubber on a metal core 130 made of SUS or aluminum. I am doing so. Further, the reapplying flocking roller 122 is configured by providing a flocking 141 having a length l ₁ made of nylon or the like on the surface of a cored bar 140 made of a metal such as SUS or aluminum.

  In this case, the second set agent application unit 12 does not include the set agent supply unit (supply unit) unlike the first set agent application unit 11. The set agent on the intermediate transfer medium 201 such as the re-application roller 121 of the second set agent application means 12 is transferred to itself and applied (re-applied) to the intermediate transfer medium 201 again. This simplifies the configuration.

  As shown in FIG. 4, a re-application roller gear 123 and a re-application flocking roller gear 124 are attached to the re-application roller 121 and the re-application flocking roller 122, and an intermediate gear 126 to which driving force is transmitted from a driving source (not shown). The re-application roller gear 123 is meshed with the re-application roller gear 123, and the re-application flocking roller gear 124 is engaged with the re-application roller gear 123.

  Accordingly, when a rotational force in the direction of the arrow is applied to the intermediate gear 126, the re-application roller 121 rotates in the direction of the arrow via the re-application roller gear 123, and the re-application flocking roller meshed with the re-application roller gear 123. The reapplication flocking roller 122 rotates in the direction of the arrow through the gear 124. That is, the re-application roller 121 rotates while contacting the intermediate transfer medium 201 in the forward direction, the re-application flocking roller 122 rotates while contacting the re-application roller 121 in the forward direction, and the re-application flocking roller 122 is intermediate. It rotates while contacting the transfer medium 201 in the opposite direction.

  Thus, the re-application roller rotates while contacting the intermediate transfer medium in the forward direction, the re-application flocking roller rotates while contacting the re-application roller in the forward direction, and contacts the intermediate transfer medium in the opposite direction. It is configured to rotate while. When the re-coating roller rotates while contacting the intermediate transfer medium in the forward direction, the set agent is contact-coated on the intermediate transfer medium, and the set agent can be reliably applied to the intermediate transfer member. By rotating the re-applying flocking roller in contact with the intermediate transfer member in the opposite direction, it is possible to disassemble the set agent on the intermediate transfer member and realize a uniform coating layer with a fine decision.

As shown in FIG. 5, the re-application roller 121 and the re-application flocking roller 122 are arranged with a biting amount δ1, and the re-application flocking roller 122 and the intermediate transfer medium 201 are arranged with a biting amount δ2. Recoated flocking roller 122, re-applying roller 121 are each rotational center O _N, rotates while contacting the forward direction of the arrow as O _T.

  As shown in FIG. 6, the contact state between the reapplication roller 121 and the reapplication flocking roller 122 is that the flocking 141 of the reapplication flocking roller 122 starts from point J where the flocking 141 of the reapplication flocking roller 122 contacts the reapplication roller 121. The flocking 141 receives a bending force and deforms by the arc JKI of the reapplying flocking roller 122 in the portion shown by hatching up to the point I away from the reapplying roller 121.

Here, the line segment _O N -O _T bristles located on 141 connecting the rotational center _{O T} of the rotational center _{O N} and reapplication roller 121 of reapplication flocking roller 122, the metal core 140 of re-applying flocking roller 122 above site of the H point and the point at which the tip portion is in contact with the re-application roller 121 and the point C, and subjected to bending displacement [delta] _S, subjected to bending forces P corresponding to the bending displacement [delta] _S.

At this time, since the biting amount [delta] ₁ of the line segment O _N -O _T bristles are on 141 is maximum, of course, also becomes maximum bending force P becomes the maximum bending displacement [delta] _S. If the deflection angle θ _N at the point C, which is the tip of the flocked hair 141 at this time, and the tangential angle of the point C in _the re-application roller 121 is θ _T , 0 to contact the re-application roller 121 at the tip of the flock 141 The relation of <θ _N <θ _T needs to be satisfied.

  By maintaining this relationship, the tip of the flocked 141 is in contact with the reapplication roller 121 while standing, and does not contact the reapplying roller 121 on the side surface of the flocked 141. Thereby, it is possible to stir and disassemble the set agent 101 on the reapplication roller 121 at the tip (tip) of the flocking 141 of the reapplication flocking roller 122 and disassemble the set agent 101 on the reapplication roller 121. It becomes a finely grained coated surface.

  On the other hand, the set agent 101 does not accumulate on the tip (tip) of the flocking 141 of the re-applying flocking roller 122 to the extent that the fine setting agent 101 adheres to the tip of the flock 141.

On the other hand, the case where the side surface of the flock 141 of the reapplication flocking roller 122 contacts the reapplication roller 121 will be described with reference to FIG.
When the length of the flocked 141 is the length l ₁ , the re-application flocking roller 122 and the re-application roller 121 are arranged with a bite amount δ ₃ larger than the bite amount δ ₁ for contacting at the tip of the flock 141 In the contact portion with the re-application roller 121, the flocked 141 comes into contact with the side surface. The set agent 101 that has become lumpy on the re-application roller 121 is agitated on the side surface of the flocking 141.

  Therefore, the set agent 101 on the re-application roller 121 enters between the side surfaces of the flocking 141 of the re-application flocking roller 122, and the space between the flocking 141 is filled with the setting agent 101, and the same set agent holding state as that of the porous body is obtained. . As a result, the mixing effect on the set goods 101 which is a stagnation on the re-application roller 121 by the tip of the flocking 141 of the re-application flocking roller 122 is not exhibited, and the setting agent 101 on the re-application roller 121 is generally fine. The coated surface is rough and granular.

  In this way, in order to form the agglomerated uniform application state of particles on the reapplication roller 121 by the agglomerated set agent 101 on the reapplication roller 121 being scraped and disassembled, the flocking 141 of the reapplication flocking roller 122 is formed. It is necessary to come into contact with the re-coating roller 121 at the tip (tip).

Next, the relationship between the re-application flocking roller 122 and the intermediate transfer medium 201 will be described with reference to FIG.
The reapplying flocking roller of the portion shown by hatching from the point J where the flocking 141 of the reapplying flocking roller 122 contacts the intermediate transfer medium 201 to the point I where the flocking 141 of the reapplying flocking roller 122 is separated from the intermediate transfer medium 201 The flock 141 is subjected to a bending force by the arc JKI 122 and deforms.

The bristles 141 from the center _{O N} of reapplication flocking roller 122 to the intermediate transfer medium 201 in grated on the vertical line _O N -C _L, a point on the intermediate transfer medium 201 of a perpendicular When F point, the bending displacement [delta] _T receiving and subjected to bending forces Q corresponding to the bending displacement [delta] _T. Since biting amount [delta] ₂ of the line segment O _N -C _L bristles are on 141 is maximum, of course, also becomes maximum bending force Q also becomes the maximum bending displacement [delta] _T.

At this time, if the deflection angle θ _N at the point C of the tip of the flocking 141 of the re-application flocking roller 122 and the tangential angle of the point C in _the intermediate transfer medium 201 are θ _T , that is, θ _T = π / 2, the re-application flocking roller In order to come into contact with the intermediate transfer medium 201 at the tip of the 122 flocks 141, it is necessary to satisfy the relationship of 0 <θ _N <θ _T = π / 2.

  By maintaining this relationship, the tip of the flocking 141 of the re-application flocking roller 122 is in contact with the intermediate transfer medium 201 in a standing state, and is not in contact with the side surface of the flocking 141. As a result, the set agent 101 that has become lumpy on the intermediate transfer medium 201 can be stirred and disassembled at the tip (tip) of the flocking 141 of the reapplying flocking roller 122, so that the set agent 101 on the intermediate transfer medium 201 can be disassembled. A finely grained coated surface can be formed.

  On the other hand, the set agent 101 does not accumulate on the tip (tip) of the flocking 141 of the reapplying flocking roller 122 to the extent that the fine set agent 101 adheres to some extent. Further, when the side surfaces of the flocked 141 are brought into contact with each other, it is not preferable because there are the same problems as described in the re-application roller 121.

  In other words, the re-applying flocking roller is able to reliably disassemble the set agent that is agglomerated by being in contact with the re-applying roller and the intermediate point transfer medium at the tip of flocking, and the set agent is inserted into the flocking. The ability to decompose the set agent can be maintained without entering.

  Next, the operation of the second set agent application unit 12 will be described. Referring to FIG. 5 described above, the image transfer indicated by (a) of the intermediate transfer medium 201 onto which the image is transferred onto the transfer paper 601. The part passes through the application roller 105 to the state indicated by (f), passes through the re-application roller 121, and becomes the part indicated by (g), and finally passes through the re-application flocking roller 122. The state of the portion indicated by (h) is conveyed to a position facing the printing means 3, and an image is formed again, passed through the transfer means 4, and transferred to the transfer paper 601, and again at (a). Return to the state shown.

  FIG. 9 shows the application state of the set agent 101 in the portion indicated by (a) to (h) on the intermediate transfer medium 201 (referred to simply as “the portion (a)”). That is, the set agent 101 does not remain in the image transfer portion PG in the portion (a) shown in FIG. 5A, but the set agent 101 remains in the non-image portion NG. A thin uniform coating layer is formed on the image transfer portion in the portion (f) shown in FIG. 7B after passing through the coating roller 105, but the set agent 101 is insufficient to transfer the image. ing. A substantially constant amount of the set agent 101 is applied to the non-image area NG.

  In the portion (G) shown in FIG. 7C that has passed through the re-application roller 121, the re-application roller 121 holds a large amount of the set agent 101 that can maintain an appropriate amount of the set agent application amount on the intermediate transfer medium 201. Yes. For this reason, the image transfer portion is applied by the re-application roller 121 in an amount necessary for the transfer as a whole of the PG, and the region S1 in which the coating unevenness is slightly agglomerated and the region S2 in which the amount of application is small and not agglomerated. It becomes light and dark streaks, resulting in a non-uniform coating layer.

  At this time, when the set agent 101 is applied to the image transfer portion PG from the re-application roller 121, the set agent decrease amount of the re-application roller 121 is supplied from the non-image portion NG of the intermediate transfer medium 201 and is always constant. The set agent 101 is held. Further, the non-image area NG is a uniform coating layer without change.

  Then, in the portion (H) that has passed through the re-application flocking roller 122, the re-application flocking roller 122 disassembles and agglomerates the set agent 101 in the image transfer portion, resulting in a fine and uniform application layer. As a whole, the image is reproduced in a reprintable state in which an appropriate amount of the setting agent 101 is applied.

  In this case, the amount of application onto the intermediate transfer medium 201 from which the set agent has been peeled off after image transfer is increased by using the second set agent applying unit 12 more than the first set agent applying unit 11. The setting agent application means 11 can maintain a uniform application state of the thin layer of the setting agent.

  As described above, in this image forming apparatus, the first set agent application unit that is the first application unit that applies the powder to the intermediate transfer medium and the second set agent application unit that is the second application unit are provided. Therefore, powder that is insufficiently supplied only by the first application means in the re-application after image transfer can be replenished and applied again by the second application means, and repeated application by movement of the intermediate transfer medium Can be eliminated, and the effective printing speed can be improved.

  In this case, by disposing the second coating unit on the downstream side of the first coating unit, the application state by the second coating unit can be prevented from affecting the first coating unit. In addition, it is possible to hold a large amount of the set agent by using a porous material for the second application means, supply a necessary amount of the set agent at the time of re-application, and agglomerated set agent by adopting a flocking roller Can be made into a layer in which the application state of the set agent of the intermediate transfer medium is made thin and uniform.

Next, a second set agent applying unit in the image forming apparatus according to the second embodiment of the present invention will be described with reference to FIG.
A re-application roller gear 123 and a re-application flocking roller gear 124 are respectively attached to and engaged with the re-application roller 121 and the re-application flocking roller 122 of the second set agent application means 122 of this embodiment. Here, unlike the first embodiment, there is no drive source such as a drive motor for rotationally driving the re-application roller 121 and the re-application flocking roller 122.

  That is, the re-application roller 121 and the re-application flocking roller 122 are configured to be rotated by contact with the intermediate transfer medium 201 (a rotational force is applied from the intermediate transfer medium 201). This eliminates the need for a special drive source and simplifies the configuration.

A contact state between the recoating roller 121 and the intermediate transfer medium 201 will be described with reference to FIG.
The shaft 121a of the re-application roller 121 is held between the side walls 127a and 27b, and the shaft 122a of the re-application flocking roller 122 is held between the side walls 127c and 127d. Then it is in a free state. Thus, re-applying roller 121, reapplication flocking roller 122, each of the center _O T, its own weight from _{O N W} 0, _{W 1} is held on the intermediate transfer medium 201.

Here, if the friction coefficient between the re-application roller 121 and the intermediate transfer medium 201 is μ _TC , and the friction coefficient between the re-application flocking roller 122 and the intermediate transfer medium 201 is μ _NC , the conveying force F ₀ of the re-application roller 121 is F _{If 0} = μ _TC × W ₀ and the radius of the re-application roller 121 is r ₀ , the transport torque T ₀ is T ₀ = F ₀ × r ₀ = μ _TC × r ₀ × W ₀ .

Similarly, the conveyance force F ₁ of the re-application flocking roller 122 is F ₁ = μ _NC × W ₁ , and assuming that the radius of the re-application flocking roller 122 is r ₁ , the conveyance torque T ₁ is T ₁ = F _1. × r ₁ = μ _NC × r ₁ × W ₁

Further, assuming that the number of teeth of the reapplication roller gear 123 is N _T and the number of teeth of the reapplication flocking roller gear 124 is N _C , the gear ratio R _T is R _T = N _C / N _T. The transport torque T ₀ of the re-application roller 121 is T _0N = T ₀ × R _T = (N _C / N _T ) × μ _TC × r ₀ × W _{O in} the re-application flocking roller 122. The conveyance direction is determined by the relationship between the conveyance torque T ₁ of the re-application flocking roller 44 and the conveyance torque T _0N of the re-application flocking roller 121 at the re-application flocking roller 122. That is, when the transport ratio and _{η TN, η TN = T 1} / T 0N = (μ NC / μ TC) × (W 1 / W 0) × (N T / N C) × (r 1 / r 0) It becomes.

Here, when the conveyance ratio η _TN > 1, the conveyance torque T ₁ of the re-application flocking roller 122 is larger than the conveyance torque T ₀ of the re-application roller 121, and the re-application roller 121 follows the rotation direction of the re-application flocking roller 122. It will be. This is not preferable because it is the reverse of the direction of rotation of the re-application roller 121 and the re-application flocking roller 122 in FIG.

Further, when the conveyance ratio η _TN = 1, the conveyance torque T ₁ of the re-application flocking roller 122 and the conveyance torque T ₀ of the re-application roller 121 do not rotate in balance, which is not preferable.

Furthermore, when the conveyance ratio η _TN <1, the conveyance torque T ₁ of the re-application flocking roller 122 is smaller than the conveyance torque T _{0 of} the re-application roller 121, and the re-application flocking roller 122 follows the rotation direction of the re-application roller 121. It will be. This coincides with the arrows in the rotation direction of the reapplication roller 121 and the reapplication flocking roller 122 in FIG.

Therefore, the friction coefficient ratio (μ _NC / μ _TC ), the load ratio (W ₁ / W ₀ ), the gear ratio (N _T / N _C ) of the rollers 121 and 122 so that the conveyance ratio η _TN <1. By appropriately selecting and combining the ratio (r ₁ / r ₀ ), the recoating roller 121 is rotated by the conveyance of the intermediate transfer medium 201 without transmitting the drive to the recoating roller 121, and the recoating flocking roller accordingly. 122 also rotates, and the application state of the set agent 101 on the intermediate transfer medium 201 can be made normal.

Next, a second set agent application unit according to the third embodiment of the present invention will be described with reference to FIG.
The second set agent application unit 122 of this embodiment also does not include a drive source such as a drive motor for rotationally driving the re-application roller 121 and the re-application flocking roller 122, but the re-application roller 121 and the re-application flocking. The roller 122 is configured to be rotated by contact with the intermediate transfer medium 201 (a rotational force is applied from the intermediate transfer medium 201), and the re-application flocking roller 122 is pressed against the re-application roller 121. This eliminates the need for a special drive source and simplifies the configuration.

That is, the shaft 121a of the re-application roller 121 is held between the side walls 127a and 27b, and the shaft 122a of the re-application flocking roller 122 is held between the side walls 127c and 127d, and is regulated in the moving direction of the intermediate transfer medium 201. While being in a free state in the vertical direction, the re-application roller 121 and the re-application flocking roller 122 are pressed by applying a pressing force P. Thus, re-applying roller 121, reapplication flocking roller 122, each of the center _O T, its own weight from _{O N W} 0, _{W 1} is held on the intermediate transfer medium 201.

Here, the friction coefficient between the re-application roller 121 and the re-application flocking roller 122 is μ _TN , the friction coefficient between the re-application roller 121 and the intermediate transfer medium 201 is μ _TC , and the friction coefficient between the re-application flocking roller 122 and the intermediate transfer medium 201. Is the _NC , the transport force F ₀ of the re-application roller 121 is F ₀ = μ _TC × W ₀ , and the radius of the re-application roller 121 is r ₀ , the transport torque T ₀ is T ₀ = F ₀ × r ₀ = μ _TC × r ₀ × W ₀

Similarly, the conveyance force F ₁ of the re-application flocking roller 122 is F ₁ = μ _NC × W ₁ , and assuming that the radius of the re-application flocking roller 122 is r ₁ , the conveyance torque T ₁ is T ₁ = F _1. × r ₁ = μ _NC × r ₁ × W ₁ The conveyance direction is determined by the relationship between the conveyance torque T ₁ of the re-application flocking roller 122 and the conveyance torque T ₀ of the re-application roller 121. That is, when the transport ratio η _TN is given, η _TN = T ₁ / T ₀ = (μ _NC / μ _TC ) × (W ₁ / W ₀ ) × (r ₁ / r ₀ ).

Here, when the conveyance ratio η _TN > 1, the conveyance torque T ₁ of the re-application flocking roller 122 is larger than the conveyance torque T _{0 of} the re-application flocking roller 121, and the re-application roller 121 is rotated in the rotation direction of the re-application flocking roller 122. Will follow. This is not preferable because it is the reverse rotation of the arrows in the rotation direction of the re-application roller 121 and the re-application flocking roller 122 in FIG.

Further, when the conveyance ratio η _TN = 1, the conveyance torque T ₁ of the re-application flocking roller 122 and the conveyance torque T ₀ of the re-application roller 121 do not rotate in balance, which is not preferable.

Furthermore, when the conveyance ratio η _TN <1, the conveyance torque T ₁ of the re-application flocking roller 122 is smaller than the conveyance torque T _{0 of} the re-application roller 121, and the re-application flocking roller 122 follows the rotation direction of the re-application roller 121. It will be. This coincides with the arrows in the rotation direction of the reapplication roller 121 and the reapplication flocking roller 122 in FIG.

Therefore, the friction coefficient ratio (μ _NC / μ _TC ), load ratio (W ₁ / W ₀ ), and roller diameter ratio (r ₁ / r ₀ ) of each roller are appropriately selected so that the conveyance ratio η _TN <1. By combining, the rotation direction of the re-application roller 121 can be determined.

In order for the re-application roller 121 to rotate at the drive torque T ₀ over the drive torque T ₁ of the re-application flocking roller 122, the transmission torque T ₂ = μ _TN × P × r ₁ > T ₁ = μ _NC × r ₁ × W ₁ is required, and is transformed to become a transmission rate η _PN = T ₁ / T ₂ = (μ _NC / μ _TN ) × (W ₁ / P). If the transmission rate η _PN > 1, the re-application flocking roller 122 slips and does not rotate, so that the transmission rate η _PN ≦ 1 is necessary. In order to cause the re-coating roller 121 to rotate and obtain the desired rotation direction, it is necessary to satisfy the relationship of the conveyance ratio η _TN <1 and the transmission ratio η _PN ≦ 1.

Therefore, the friction coefficient ratio of the roller (μ _NC / μ _TC ), (μ _NC / μ _TN ), load ratio (W ₁ / W ₀ ), (W ₁ / P), roller diameter ratio (r ₁ / r ₀ ) By appropriately selecting and combining the two, the re-application roller 121 and the re-application flocking roller 122 rotate by the conveyance of the intermediate transfer medium 201 without providing a drive transmission means to the re-application flocking roller 122, and the expected rotation is obtained. The application state of the set agent 101 on the intermediate transfer medium 201 can be made normal.

  In the description here, the conveyance direction of the intermediate transfer medium 201 is horizontal and the pressing force P is provided between the re-application roller 121 and the re-application flocking roller 122. However, the conveyance direction of the intermediate transfer medium 201 is not necessarily horizontal. Absent.

For example, as shown in FIG. 13, when tilting the conveying direction of the intermediate transfer medium 201 relative to the horizontal by an angle theta _N, load W ₁ of reapplication flocking roller 122 and the intermediate transfer medium 201 and the perpendicular component W ₃ It can be decomposed into O _T -O _N direction component P. When the angle of the vertical direction and _O T -O _N direction and theta _T, the intermediate transfer medium 201 and the perpendicular component _{W 3} load W _{1 is, W 3 = W 1 × Sinθ} T / Sin (θ T + θ N), O _T -O _N direction component P becomes _{P = W 1 × Sinθ N /} Sin (θ T + θ N). Based on these values, the above-described transport ratio η _TN and transmission rate η _PN may be obtained. Further, it Atehamere the _W 2 = _{W 0 cosθ N} as the conveying force of the re-application roller 121.

  In this way, the pressing force for pressing the re-application flocking roller and the re-application roller by giving the intermediate transfer medium an inclination and using the component of the re-application flocking roller in the center direction of the re-application flocking roller as the pressing force. No special configuration is required.

  As described above, the intermediate transfer medium 201 and the reapplying flocking roller 122 are rotated in contact with each other in the opposite direction, so that the set on the intermediate transfer medium 201 at the front end (tip) of the flocking 141 becomes a mess. The agent 101 is agitated and decomposed to make the set agent 101 on the intermediate transfer medium 201 a fine grained application surface. By rotating in contact with the recoating roller 121 in the forward direction, the set agent 101 that has become lumpy on the reapplying roller 121 is disassembled at the tip (tip) of the flocking, and the set agent 101 is applied to the finely particulate application surface. However, a large amount of the set agent 101 does not transfer to the reapplying flocking roller 122.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment of the present invention. It is explanatory drawing explaining the relationship between the frequency | count of application | coating and a coating amount when the 2nd set agent application | coating means is not provided in the image forming apparatus. It is explanatory drawing similarly used for description of the frequency | count of application | coating and an application | coating state. It is explanatory drawing with which it uses for description of the rotation transmission system of the 2nd set agent application | coating means of the image forming apparatus. It is explanatory drawing with which it uses for description of a structure of the said 2nd set agent application | coating means. It is explanatory drawing with which it uses for description of the contact state of the re-application flocking roller and re-application roller of the said 2nd set agent application | coating means. It is explanatory drawing with which it uses for description of the comparative example of the contact state of a re-application flocking roller and a re-application roller similarly. It is explanatory drawing with which it uses for description of the contact state of a re-application flocking roller and an intermediate transfer body similarly. It is explanatory drawing with which it uses for description of the application | coating state in the image forming apparatus. It is explanatory drawing with which it uses for description of the other example of the rotation transmission system of a 2nd set agent application | coating means. It is explanatory drawing with which it uses for description of the 2nd set agent application | coating means in the image forming apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing with which it uses for description of the 2nd set agent application | coating means in the image forming apparatus which concerns on 3rd Embodiment of this invention. It is explanatory drawing with which it uses for description of the other example of the 2nd set agent application | coating means in the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... 1st set agent application means 12 ... 2nd set agent application means 2 ... Intermediate means 3 ... Copying means 4 ... Transfer means 5 ... Cleaning means 6 ... Paper feed means 7 ... Registration means 8 ... Paper discharge means DESCRIPTION OF SYMBOLS 9 ... Controller 101 ... Setting agent 103 ... Replenishing stirring roller 104 ... Intermediate roller 105 ... Application roller 106 ... Leveling roller 121 ... Re-application roller 122 ... Re-application flocking roller 201 ... Intermediate transfer medium 301 ... Recording head 401 ... Transfer roller 501 ... Cleaning roller 601 ... Transfer paper (recording medium)

Claims (15)

  A liquid discharge head that discharges liquid droplets of the recording liquid, an intermediate transfer medium that moves with a gap to the liquid discharge head, and a recording liquid image is formed on the intermediate transfer medium by the liquid discharge head; An image forming apparatus comprising: means for transferring the recording liquid image from the intermediate transfer medium to a recording medium; and means for applying a water-absorbing powder to the intermediate transfer medium. An image forming apparatus comprising a first application unit and a second application unit for applying.   2. The image forming apparatus according to claim 1, wherein the second application unit moves the intermediate transfer medium more than the liquid discharge head on the downstream side in the movement direction of the intermediate transfer medium with respect to the first application unit. An image forming apparatus, wherein the image forming apparatus is disposed upstream in the direction.   3. The image forming apparatus according to claim 1, wherein the powder is supplied to the second coating unit from the intermediate transfer medium. 4.   4. The image forming apparatus according to claim 1, wherein the second coating unit is more than a coating amount of the first coating unit on the intermediate transfer medium medium from which the powder is peeled after image transfer. An image forming apparatus characterized by having a large amount of coating.   5. The image forming apparatus according to claim 1, wherein the second coating unit includes a re-coating roller that holds the powder and contacts the intermediate transfer medium, and the re-coating roller and the intermediate transfer. An image forming apparatus comprising: a re-applying flocking roller having flocking in contact with a medium.   The image forming apparatus according to claim 5, wherein the re-application roller rotates while contacting the intermediate transfer medium in a forward direction, and the re-application flocking roller rotates while contacting the re-application roller in a forward direction, An image forming apparatus that rotates while contacting in the opposite direction to the intermediate transfer medium.   7. The image forming apparatus according to claim 5, wherein the re-application flocking roller is in contact with the re-application roller and the intermediate point transfer medium at a tip of the flocking. 8.   8. The image forming apparatus according to claim 5, wherein a contact angle of the flock at a contact point between the flocking of the re-application flocking roller and the re-application roller is smaller than a tangential angle of the re-application roller. An image forming apparatus.   8. The image forming apparatus according to claim 5, wherein a contact angle of the flocking at a contact point between the flocking of the re-application flocking roller and the intermediate transfer medium is smaller than a tangential angle of the intermediate transfer medium. An image forming apparatus.   8. The image forming apparatus according to claim 5, wherein a contact angle of the flocking at a contact point between the flocking of the reapplication flocking roller and the reapplication roller is smaller than a tangential angle of the reapplication roller, An image forming apparatus, wherein a contact angle of the flocking at a contact point between the flocking roller and the intermediate transfer medium is smaller than a tangential angle of the intermediate transfer medium.   11. The image forming apparatus according to claim 5, wherein the application roller and the re-application flocking roller of the second application unit are rotated by the movement of the intermediate transfer medium. 12. The image forming apparatus according to claim 11, wherein a coefficient of friction between the re-application roller and the intermediate transfer medium is μ _TC , a coefficient of friction between the re-application flocking roller and the intermediate transfer medium is μ _NC , and the re-application roller. W ₀ , the self-weight of the re-application flocking roller is W ₁ , the radius of the re-application flocking roller is r ₀ , the radius of the re-application flocking roller is r ₁ , and the number of teeth of the gear provided on the re-application roller N _T , where N _C is the number of gear teeth provided on the reapplying flocking roller, (μ _NC / μ _TC ) × (W ₁ / W ₀ ) × (N _T / N _C ) × (r ₁ / The image forming apparatus, wherein the transport ratio η _TN obtained by r ₀ ) satisfies the relationship η _TN <1.   11. The image forming apparatus according to claim 5, wherein the application roller and the re-application flocking roller of the second application unit are rotated by the movement of the intermediate transfer medium, and the re-application flocking roller is An image forming apparatus, wherein the image forming apparatus is pressed against a coating roller. 14. The image forming apparatus according to claim 13, wherein a friction coefficient between the re-application roller and the intermediate transfer medium is μ _TC , a friction coefficient between the re-application flocking roller and the intermediate transfer medium is μ _NC , and the re-application roller The friction coefficient of the re-application flocking roller is μ _TN , the weight of the re-application flocking roller is W ₀ , the weight of the re-application flocking roller is W ₁ , the radius of the re-application roller is r ₀ , and the radius of the re-application flocking roller Where r _{1 is} the pressing force and P is the pressing force, the transport ratio η _TN obtained by (μ _NC / μ _TC ) × (W ₁ / W ₀ ) × (r ₁ / r ₀ ) is η _TN <1 And a transmission rate η _PN obtained by (μ _NC / μ _TN ) × (W ₁ / P) satisfies the relationship of η _PN ≦ 1.   15. The image forming apparatus according to claim 13, wherein a component of the weight of the re-application flocking roller in the center direction of the re-application roller is used as the pressing force by inclining the intermediate transfer medium. Image forming apparatus.

Images