JP2012058633A - Image forming device, image forming system and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly prevent print quality deterioration by a contact trace generated when a cleaning member contacts with a transfer roller.SOLUTION: A contact trace is made generated on a peripheral surface of a secondary transfer roller 4 (a peripheral surface between positions P3 and P4) contacting a region ARon of a holding region GA by controlling contact timing of a cleaning blade 451. Accordingly, even though the contact trace on the peripheral surface of the secondary transfer roller 4 is transferred on a transfer member S, because its transferred position is the holding region GA of the transfer member S, dirt on print by the contact trace is certainly avoided assuring the prevention of print quality deterioration.

Description

  The present invention relates to an image forming apparatus, an image forming system, and an image forming system that obtains a printed material by cutting the transfer material after the image is transferred to the printed material region of the transfer material using a transfer roller having a grip portion disposed in the concave portion of the peripheral surface. The present invention relates to an image forming method.

  As an image forming apparatus that transfers an image to a transfer material using a transfer roller in which a grip portion is disposed in a concave portion of the peripheral surface, for example, an apparatus described in Patent Document 1 is known. In this apparatus, a gripper such as a gripper grips the leading end of the transfer material to position the transfer material with respect to the transfer roller, and moves the transfer material in a predetermined direction by the rotation of the transfer roller. When the transfer roller rotates by a predetermined distance, the grip of the transfer material front end by the grip is released, and the front end of the transfer material is peeled off from the peripheral surface of the transfer roller and moved toward the fixing unit. In this way, the image is transferred to the transfer material while moving the transfer material. Further, during the rotation of the transfer roller, the cleaning member comes into contact with the peripheral surface of the transfer roller and the residual liquid developer attached to the peripheral surface is removed by cleaning.

Japanese Patent Laying-Open No. 2010-170005 (for example, FIG. 1)

  By the way, when cleaning the transfer roller having the recess provided on the peripheral surface as described above, it is necessary to bring the cleaning member into contact with the transfer roller. However, when the cleaning member is brought into contact with the transfer roller, a toner pool called a contact mark remains on the peripheral surface of the transfer roller at the contact start position, thereby fouling the transfer material and degrading the quality of the final printed matter. The problem of inviting may occur.

  An object of some aspects of the present invention is to provide a technique for reliably preventing the quality of a printed product from being deteriorated due to contact marks generated when a cleaning member contacts a transfer roller.

  In order to achieve the above object, an image forming apparatus according to the present invention is provided with an image carrier that carries an image, a concave portion on a peripheral surface, and a grip portion that grips a transfer material in the concave portion. A transfer roller for transferring the image carried on the image carrier to the held transfer material, a cleaning member that contacts the transfer roller to clean the peripheral surface of the transfer roller, and a cleaning member that contacts the peripheral surface of the transfer roller Alternatively, an operation unit that moves the image to a position where the image is transferred, a cutting unit that cuts the transfer material on which the image has been transferred by the transfer roller, into a gripping region gripped by the gripping unit and a transfer region to which the image has been transferred, And a control unit that contacts the cleaning member at a position on the peripheral surface of the transfer roller that contacts the gripping region of the transfer material.

  In order to achieve the above object, the image forming system according to the present invention is provided with an image carrier that carries an image, a grip portion that has a recess on the peripheral surface and grips a transfer material in the recess. A transfer roller that transfers the image carried on the image carrier onto the transfer material held in step, a cleaning member that contacts the transfer roller to clean the peripheral surface of the transfer roller, and a cleaning member that contacts the peripheral surface of the transfer roller Alternatively, an image forming unit including an operation unit that moves the image to a position that is separated, a transport unit that transports a transfer material onto which an image has been transferred by the image forming unit, and a transfer material transported by the transport unit are gripped by the grip unit. A cutting unit that cuts the grip region and the transfer region to which the image has been transferred, and a control unit that causes the cleaning member to abut at a position on the peripheral surface of the transfer roller that abuts the grip region of the transfer material by the operation of the operation unit; Have It is characterized in Rukoto.

  Furthermore, in order to achieve the above object, the image forming method according to the present invention transports a transfer material and grips the transported transfer material with a gripping portion disposed in a recess formed on the peripheral surface of the transfer roller. The image carried on the image carrier is transferred to the transfer material gripped by the gripping portion by the transfer roller, and the transfer material on which the image is transferred is separated from the transfer roller and conveyed to the cutting portion, and separated from the transfer material. The peripheral surface of the transfer roller is contacted with the cleaning member at the position of the peripheral surface that is in contact with the gripping area gripped by the gripping portion of the transfer material to clean the peripheral surface of the transfer roller, and the transfer material is The gripping area and the transfer area to which the image is transferred are cut out.

  In the invention configured as described above (image forming apparatus, image forming system, and image forming method), the grip area of the transfer material is gripped by the grip portion. Then, the cleaning member comes into contact with the peripheral surface of the transfer roller in contact with the transfer region of the transfer material, and the peripheral surface of the transfer roller is cleaned. Therefore, the contact mark is formed at the contact start position of the cleaning member with respect to the peripheral surface of the transfer roller by the contact of the cleaning member, and then transferred to the transfer material. It is a gripping area and is separated from the transfer area by a cutting process. As a result, the printed matter is prevented from being soiled by the contact mark, and the quality of the printed matter is reliably prevented from being deteriorated.

  In addition, the cleaning member that is in contact with the transfer roller is preferably separated from the transfer roller at a position on the peripheral surface that is different from the position of the peripheral surface of the transfer roller that is in contact with the transfer material. It is possible to reliably prevent the separation stripe from being transferred to the transfer material.

1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. The block diagram which shows the electric constitution of the apparatus of FIG. The figure which shows the surrounding surface of a secondary transfer roller. The figure which shows the structure and operation | movement of a separation contact cam mechanism. The timing chart which shows the separation-contact operation | movement of a cleaning blade. The figure which shows typically the separation-contact operation | movement of a cleaning blade. 1 is a diagram showing an embodiment of an image forming system according to the present invention. The figure which shows the modification of the image forming apparatus and image forming system concerning this invention.

  FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the apparatus shown in FIG. Further, FIG. 3 is a view showing a peripheral surface of a secondary transfer roller provided in the apparatus shown in FIG. The image forming apparatus 1 prints a color image or a monochrome image on a printed region of a sheet-shaped transfer material S such as copy paper, transfer paper, paper, and an OHP transparent sheet, and the printing unit 100 prints the image. The transfer body S is cut into a printing part area and a non-printing part area, and a cutting part 200 for obtaining a printed matter consisting only of the printing part area and a control part 300 for controlling the entire apparatus are integrally provided in the apparatus main body. ing.

  The printing unit 100 includes four image forming stations 2Y (for yellow), 2M (for magenta), 2C (for cyan), and 2K (for black) that form images of different colors. When an image forming command is given from an external device such as a host computer to the controller 310 of the control unit 300 having a CPU, a memory, etc., the controller 310 controls each unit of the printing unit 100 to execute a predetermined image forming operation. Then, an image corresponding to the image formation command is formed on the transfer material S.

  Each of the image forming stations 2Y, 2M, 2C, and 2K is provided with a photosensitive drum 21 on which a toner image of each color is formed. The photosensitive drums 21 are arranged such that the rotation axis thereof is parallel or substantially parallel to the main scanning direction (direction perpendicular to the paper surface of FIG. 1), and a predetermined speed is indicated in the direction of arrow D21 in FIG. Is driven to rotate.

  Around each photosensitive drum 21, a charger 22 that is a corona charger that charges the surface of the photosensitive drum 21 to a predetermined potential and an electrostatic latent image by exposing the surface of the photosensitive drum 21 according to an image signal. An exposure unit 23 that forms an image, a developing unit 24 that visualizes the electrostatic latent image as a toner image, a first squeeze unit 25, a second squeeze unit 26, and the toner image on the intermediate transfer belt 31. A transfer unit for primary transfer and a cleaning blade for cleaning the surface of the photosensitive drum 21 after the transfer are arranged along the rotation direction D21 (clockwise in FIG. 1) of the photosensitive drum 21 in this order. ing.

  The charger 22 does not come into contact with the surface of the photosensitive drum 21, and a conventionally well-known and commonly used corona charger can be used as the charger 22. When a scorotron charger is used as the corona charger, a wire current flows through the charge wire of the scorotron charger and a direct current (DC) grid charging bias is applied to the grid. When the photosensitive drum 21 is charged by corona discharge by the charger 22, the surface potential of the photosensitive drum 21 is set to a substantially uniform potential.

  The exposure unit 23 exposes the surface of the photosensitive drum 21 with a light beam in accordance with an image signal given from an external device to form an electrostatic latent image corresponding to the image signal. The exposure unit 23 can be constituted by a light beam from a semiconductor laser that is scanned by a polygon mirror, or a line head in which light emitting elements are arranged in the main scanning direction.

  Toner is applied to the electrostatic latent image formed in this manner from a developing roller 241 provided in the developing unit 24, and the electrostatic latent image is developed with toner. In the developing unit 24 of the image forming apparatus 1, toner development is performed using a liquid developer in which toner is dispersed in a carrier liquid in an approximate weight ratio of about 20%. The liquid developer used in this embodiment is a low-concentration (1 to 2 wt%) and low-viscosity volatility that is generally used in the past, using Isopar (trademark: Exon) as a carrier liquid. It is not an ionic liquid developer but a non-volatile liquid developer having a high concentration and high viscosity and having non-volatility at room temperature. That is, the liquid developer in the present embodiment is obtained by dispersing solid particles having an average particle diameter of 1 μm in which a colorant such as a pigment is dispersed in a thermoplastic resin in a liquid solvent such as an organic solvent, silicone oil, mineral oil, or edible oil. High viscosity with a toner solid content concentration of about 20% (HAAKE RheoStress RS600 is used, and the viscoelasticity at a shear rate of 1000 (1 / S) at 25 ° C. is 30 to 300 mPa · s. Liquid developer.

  A first squeeze portion 25 is disposed on the downstream side of the developing position in the rotation direction D 21 of the photosensitive drum 21, and a second squeeze portion 26 is disposed on the downstream side of the first squeeze portion 25. The squeeze rollers 25 and 26 are respectively provided with squeeze rollers. Each squeeze roller comes into contact with the surface of the photosensitive drum 21 to remove excess carrier liquid and fog toner from the toner image. In the present embodiment, the excess carrier liquid and fog toner are removed by the two squeeze portions 25 and 26. However, the number and arrangement of the squeeze portions are not limited to this, for example, one squeeze portion. May be arranged.

  The toner image that has passed through the squeeze portions 25 and 26 is primarily transferred to the intermediate transfer belt 31 by the transfer unit. The intermediate transfer belt 31 is stretched around belt stretching rollers 32 to 35 that are spaced apart from each other, and is rotated in a predetermined direction D31 by roller driving by a belt driving motor M3. More specifically, the right roller 32 in FIG. 1 among the belt stretching rollers 32 to 35 is a driving roller, and a belt driving motor M3 is mechanically connected to the driving roller 32. In the present embodiment, a driver 311 is provided to drive the belt drive motor M3, and a drive signal corresponding to a command pulse given from the controller 310 is output to the belt drive motor M3 for position control. As a result, the belt driving roller 32 rotates in the arrow direction D32 in FIG. 1 at a peripheral speed corresponding to the command pulse, and the surface of the intermediate transfer belt 31 rotates in the direction D31 at a constant speed.

  The transfer unit includes a primary transfer roller 271, and the primary transfer roller 271 is disposed at the primary transfer position TR 1 so as to face the photosensitive drum 21 with the intermediate transfer belt 31 interposed therebetween, and a toner image on the photosensitive drum 21. Is transferred to the intermediate transfer belt 31. Then, the transfer of the toner image is executed by the transfer unit of each color, so that the toner images of each color on the photosensitive drum 21 are sequentially superimposed on the intermediate transfer belt 31 to form a full color toner image.

  The toner image thus transferred to the intermediate transfer belt 31 is conveyed to the secondary transfer position TR2. At the secondary transfer position TR2, the secondary transfer roller 4 faces the driving roller 32 and the driven roller 34 with the intermediate transfer belt 31 in between, and also faces the intermediate transfer belt 31 wound around both rollers 32 and 34. The transfer nip NP is formed. Further, the secondary transfer roller 4 is rotationally driven by the secondary transfer roller drive motor M4 and rotates in the arrow direction D4 in FIG. The secondary transfer roller drive motor M4 is driven and controlled by a drive signal output from the driver 312 in response to a command pulse from the controller 310.

  At the secondary transfer position TR2, a single color or a plurality of color toner images formed on the intermediate transfer belt 31 is transferred from the gate roller 51 (a pair of rollers 51a and 51b) along the transfer path PT. Secondary transfer. A transfer material guide 52 for feeding the transfer material S to the secondary transfer position TR2 without contacting the secondary transfer roller 4 or the intermediate transfer belt 31 is provided between the gate roller 51 and the secondary transfer position TR2. It is arranged.

  In this embodiment, the rotational phase of the secondary transfer roller 4 can be detected as follows. That is, the detected portion 91 is disposed on the rotary shaft 421 of the secondary transfer roller 4. The detected portion 91 is formed in a disk shape having a slit-like cutout portion 911 in a part of the peripheral surface, and rotates with the rotation of the secondary transfer roller 4. On the other hand, a detection unit 92 including a photo sensor such as a photo interrupter is provided on the apparatus housing side. Each time the notch 911 of the detected part 91 passes the detection position by the detection part 92 with the rotation of the secondary transfer roller 4, the detection part 92 synchronizes with the rotation of the secondary transfer roller 4. Output a signal. As a result, the rotational phase of the secondary transfer roller 4 is detected, and the controller 310 controls the operation timing of each part of the apparatus based on the synchronization signal Vsync, and the leading end of the transfer material S fed to the secondary transfer position TR2 ( The gripping area) is gripped by the gripping portion of the secondary transfer roller 4 to move the transfer material S in a predetermined movement direction D4, and the toner image (image) is transferred to the transfer area of the transfer material S. The configuration of the secondary transfer roller 4, the positional relationship between the secondary transfer roller 4 and the transfer material S, the secondary transfer operation, and the like will be described in detail later.

  The transfer material S on which the toner image is secondarily transferred is sent from the secondary transfer roller 4 to the transport mechanism 6 along the transport path PT. In the transport mechanism 6, the first suction unit 61, the transfer material transport unit 62, and the second suction unit 63 are sequentially arranged along the transport path PT, and these cooperate to transport the transfer material S to the fixing unit 7. To do. At this time, the transfer material S is conveyed while the upper surface opposite to the image transfer surface is adsorbed in a posture in which the image transfer surface to which the toner image has been transferred from the intermediate transfer belt 31 is directed vertically downward. Transported). In FIG. 1, the white arrows attached to the first suction unit 61, the transfer material transport unit 62, and the second suction unit 63 indicate the direction of the airflow formed when these units are operated to suck the transfer material S. Is shown.

  A number of through holes are provided in the lower surface (suction surface) 611 of the housing portion 613 of the first suction portion 61, and an intake fan 614 is provided in the upper portion. When the air flow in the direction of the white arrow is generated by the operation of the intake fan 614, the inside of the housing portion 613 becomes negative pressure, and ambient air is sucked from the through hole of the lower surface 611. By bringing the transfer material S into close contact with the surface 611, the transfer material S is sucked and held by the first suction portion 61. The same applies to the transfer material conveyance unit 62 and the second suction unit 63, but the transfer material conveyance unit 62 further has a function of conveying the transfer material S toward the rear fixing unit 7 by the belt 621 that circulates.

  Whether or not the transfer material S exists in the vicinity of the lower surface 611 of the first suction portion 61 disposed adjacent to the rear of the secondary transfer roller 4 in the transport direction of the transfer material S along the transport path PT. A transfer material detection sensor 612 for detecting the above is provided. An output signal of the transfer material detection sensor 612 is input to the controller 310.

  In addition, in order to reliably feed the transfer material S on which the toner image has been secondarily transferred to the first suction unit 61 and to prevent image fouling, in this embodiment, the secondary transfer position TR2 and the first suction unit 61 are used. The air blowing unit 8 is arranged so as to face the secondary transfer roller 4 between the two. In the blower unit 8, the gripping portion of the secondary transfer roller 4 is discharged by discharging the airflow from the opening 83 of the housing portion 82 generated by the operation of the blower fan 81 that generates the airflow, as indicated by the white arrow. An airflow is blown between the transfer material S released from the grip 44 and the intermediate transfer belt 31, and the transfer material S is separated from the intermediate transfer belt 31.

  Further, the peeled transfer material S is pressed against the peripheral surface of the secondary transfer roller 4 by an air current blown to the image transfer surface of the transfer material S, and is conveyed by the rotation of the secondary transfer roller 4. Thus, the leading end portion of the transfer material S is fed toward the first suction portion 61. Further, when the rear end portion of the transfer material S is discharged from the secondary transfer position TR2 due to the air current blown to the transfer material S, the rear end portion touches the intermediate transfer belt 31 and the like, and the image is stained. Can be prevented.

  Further, a fixing unit 7 is disposed on the downstream side of the transport path PT, that is, on the side opposite to the secondary transfer roller 4 with respect to the transport mechanism 6 (the left hand side in FIG. 1), and is transferred to the transfer material S. Heat or pressure is applied to the toner image, and the toner image is fixed to the transfer material S. After the fixing is completed, the transfer material S is conveyed to the cutting unit 200, and after the transfer material S is cut into the grip area GA (FIG. 3) and the transfer area TA (FIG. 3), the transfer area is further transferred as necessary. The both width end portions of TA are cut to obtain a final printed matter having a desired size. The gripping area GA is set in advance. For example, when a cross cut mark is printed on the transfer material S and the cutting unit 200 performs cutting according to the cut mark, the grip area GA is defined by the cut mark provided on the leading end side of the transfer material S. The upstream area (rear end side) is the transfer area TA. On the other hand, without cutting the cutting mark, for example, the cutting may be performed at a position away from the front end of the transfer material S to which the image is transferred by a predetermined distance. Is defined as a gripping area GA, and an area upstream (rear end side) of the gripping area GA is a transfer area TA.

  The cutting unit 200 is equipped with two types of cutting mechanisms 210 and 220. One cutting mechanism 210 has a pair of cutting blades 211 extending in the width direction of the transfer material S (a direction orthogonal to the paper surface of FIG. 1), for example. When the boundary between the transfer area TA and the gripping area GA is positioned between the cutting blades 211, the cutting blade 211 cuts the transfer material S along the boundary in accordance with the cutting command from the controller 310, and the moving direction The length of the transfer material S at D4 is adjusted. In the other cutting mechanism 220, for example, two pairs of rotary blades 221 each having a truncated cone shape are arranged in the width direction of the transfer material S, respectively. Then, while the transfer material S is conveyed, the rotary blade 221 cuts off both width ends of the transfer area TA in accordance with a cutting command from the controller 310 and adjusts the width of the transfer material S as necessary. In this way, a desired final printed matter is obtained and carried out from the image forming apparatus 1, while the trimmed gripping area GA (and both width end portions) is collected in a collection box (not shown) provided in the trimming unit 200. Is done. The configuration of the cutting unit 200 is not limited to that shown in FIG. 1, and a cutting mechanism that has been frequently used in the past can be used.

  Returning to the printing unit 100, the configuration description will be continued. A cleaning blade 391 is in contact with the intermediate transfer belt 31 onto which the toner image has been secondarily transferred. More specifically, the cleaning blade 391 contacts the roller 33 around which the intermediate transfer belt 31 is wound downstream of the secondary transfer position TR2 in the transport direction D31 of the intermediate transfer belt 31 via the intermediate transfer belt 31. It touches. The cleaning blade 391 removes residual deposits such as toner and carrier liquid remaining on the surface of the intermediate transfer belt 31 after the secondary transfer.

  In addition to the voltage generator that generates a bias voltage supplied to each part of the apparatus, the secondary transfer roller 4 and the belt drive roller 32 described above, the apparatus 1 rotates the gate roller 51 as shown in FIG. A motor M5 for driving the motor M5, a driver 313 for driving the motor M5, and various drive mechanisms for driving other parts of the apparatus. These operations are all controlled by the controller 310.

  In this embodiment, the toner image is formed by a wet development method in which a toner image is formed using a liquid developer. Therefore, the secondary transfer roller 4 having a grip portion is used so that a sufficient transfer pressure can be applied to the transfer material S while preventing the transfer material S from sticking to the intermediate transfer belt 31. Hereinafter, the structure of the secondary transfer roller 4 will be described in detail with reference to FIGS.

  Although only the side surface of the secondary transfer roller 4 is shown in FIGS. 1 and 3, the secondary transfer roller 4 is formed by cutting out a part of the outer peripheral surface of the cylinder in a direction perpendicular to the paper surface of FIGS. 1 and 3. It has the roller base material 42 provided with the recessed part 41 which becomes. The roller base material 42 is provided with a rotating shaft 421 extending in a direction orthogonal to the paper surface. The rotation shaft 421 is provided so as to be rotatable about an axis 4211 with respect to the support arm 40 pivotally supported by an apparatus housing (not shown). The support arm 40 is swingable about the support shaft 401 with respect to the apparatus housing, and is urged counterclockwise in FIG. 1 by urging means (not shown). Therefore, the secondary transfer roller 4 is urged in the direction of the arrow α and is pressed against the intermediate transfer belt 31 between the rollers 32 and 34. As a result, the secondary transfer roller 4 is pressed against the intermediate transfer belt 31 with a predetermined load (for example, 60 kgf).

  Further, bearings 322 (see FIG. 1) are provided at both ends of the driving roller 32 around which the intermediate transfer belt 31 is wound, coaxially with the driving roller 32 and rotatable independently of the driving roller 32. When the contact member 47 (see FIG. 1) disposed at a position corresponding to the concave portion of the secondary transfer roller 4 faces the drive roller 32 side, the outer peripheral surface of the contact member 47 and the outer peripheral surface of the bearing 322 Abut each other. For this reason, the member disposed in the concave portion of the secondary transfer roller 4 is prevented from coming into contact with the intermediate transfer belt 31.

  Further, an elastic sheet formed of an elastic material such as rubber or resin is wound around the outer peripheral surface of the roller base material 42, that is, the surface region excluding the region corresponding to the inside of the recess 41 on the surface of the metal plate. An elastic layer 43 is formed by the sheet. In this embodiment, the elastic sheet is not bonded to the secondary transfer roller 4 and can be exchanged in order to cope with deterioration over time such as wear and scratches on the elastic sheet (elastic layer 43). .

  In this embodiment, the opening length (opening width) of the recess 41 along the rotation direction D4 of the roller base material 42 is about 105 mm. When the elastic layer 43 formed in the region excluding the concave portion 41 on the outer peripheral surface of the secondary transfer roller 4 is in a position facing the intermediate transfer belt 31, the elastic layer 43 is placed on the intermediate transfer belt 31 between the rollers 32 and 34. The transfer nip NP is formed by pressing. Therefore, when the concave portion 41 of the secondary transfer roller 4 faces the intermediate transfer belt 31, the transfer nip temporarily disappears.

  The length of the elastic layer 43 along the rotation direction D4 of the roller base material 42 is set to about 495 mm, and this is the largest size of the transfer material S that can be used in the apparatus 1 is wound. It is something that can be done. That is, the length of the elastic layer 43 is determined to be longer than the length of the usable transfer material S that has the maximum length along the rotation direction D4 of the roller base material 42.

  A grip 44 for gripping the transfer material S is disposed inside the recess 41. The gripping portion 44 includes a gripper support member 441 erected on the outer peripheral surface of the roller base 42 from the inner bottom portion of the recess 41, and a gripper member 442 that is supported so as to be able to come into contact with and separate from the distal end portion of the gripper support member 441. Have multiple pairs. These pairs are discretely provided in the axial direction of the secondary transfer roller 4. The leading end of the gripper member 442 is reciprocated in the radial direction of the secondary transfer roller 4 so as to be separated from the leading end of the gripper support member 441 to prepare and release the gripping of the transfer material S, while the gripper member 442 The leading end of the transfer material S is moved to the leading end of the gripper support member 441 so that the leading end of the transfer material S is gripped. Note that reference numeral 449 in FIG. 1 denotes a transfer material peeling member, which is appropriately disposed between the pair of the gripper member 442 and the gripper support member 441 in the axial direction of the secondary transfer roller 4. The transfer material peeling member 449 projects and moves outward in the radial direction of the secondary transfer roller 4, so that the transfer material S held by the gripper member 442 and the gripper support member 441 is transferred to the secondary transfer roller 4. It acts to push away from the direction.

As described above, in this embodiment, a structure in which the transfer material S is gripped by the gripping portion 44 is employed, but the positional relationship between the secondary transfer roller 4 and the transfer material S is as shown in FIG. . That is, in the drawing, the peripheral surface development view in which the peripheral surface of the secondary transfer roller 4 is developed by one turn around the movement direction D4 from the position P1, and the cleaning of the peripheral surface of the secondary transfer roller 4 in the peripheral surface development view. The figure showing the separation contact area of the blade 391 is shown, and the positions P1 to P5 are respectively the position P1: the downstream end position of the recess 41 in the rotational direction D4 of the secondary transfer roller 4,
Position P2: gripping position of the transfer material S by the gripping part 44 position P3: upstream end position of the recess 41 in the rotational direction D4 of the secondary transfer roller 4;
Position P4: a position where the downstream end of the transfer area TA in the moving direction D4 of the transfer material S (the upstream end of the gripping area GA) abuts.
Position P5: a position where the upstream end of the transfer area TA in the moving direction D4 of the transfer material S contacts,
Means. In this embodiment, the length of the transfer material S in the moving direction D4 (distance from the position P2 to the position P5) excludes the concave portion 41 of the secondary transfer roller 4 as shown in the development of the peripheral surface in FIG. The length of the peripheral surface (the distance from the position P3 to the position P1 (P1 ′) of the next round) is shorter, and with this transfer material S, the leading end (the downstream end in the moving direction D4) is the secondary transfer roller 4. The gripping area GA is gripped by the gripping part. A downstream side of the gripping area GA in the moving direction D4 (left side in the figure), that is, a rear end side of the transfer material S is a transfer area TA, and each image forming station 2Y, 2M, 2C And a toner image formed at 2K is transferred. That is, as shown in the developed view of FIG. 5, the grip area GA of the transfer material S is gripped by the grip portion 44 at the position P2, and is positioned at the position P4 beyond the position P3. Further, the transfer area TA of the transfer material S abuts on the peripheral surface of the secondary transfer roller 4 between the positions P4 and P5. Further, an area ARon sandwiched between the position P3 and the position P4 on the peripheral surface of the secondary transfer roller 4 is an area where the gripping area GA of the transfer material S contacts the peripheral surface of the secondary transfer roller 4. This corresponds to the “circumferential surface of the transfer roller in contact with the transfer material gripping region” of the invention. Further, an area ARoff sandwiched between the position P5 and the position P1 ′ is an area where the transfer material S does not contact the peripheral surface of the secondary transfer roller 4 at all. Corresponds to a “peripheral surface different from the position of the peripheral surface”.

  In addition, a cleaning unit 45 is provided facing the secondary transfer roller 4 to remove the liquid developer adhering to the secondary transfer roller 4 by cleaning. The cleaning unit 45 is disposed below the cleaning blade 451 and is disposed below the cleaning blade 451. The cleaning blade 451 is provided at a predetermined CB separation / contact position so as to be capable of separation / contact with the peripheral surface of the secondary transfer roller 4. And a separating member cam mechanism 453 that drives the cleaning blade 451 to separate and contact the peripheral surface of the secondary transfer roller 4.

  FIG. 4 is a diagram showing the configuration and operation of the separation cam mechanism. The separation cam mechanism 453 includes a support member 453a that supports the cleaning blade 451 at the tip. The tip of the support member 453a is pivotally supported by a rotation fulcrum shaft 453b. One end of a biasing member 453c is attached to the center of the support member 453a, and the support member 453a is integrated with the cleaning blade 451 around the rotation fulcrum shaft 453b by the biasing force of the biasing member 453c. Is biased counterclockwise in FIG. Furthermore, the peripheral surface of the cam member 453d is engaged with the rear end portion of the support member 453a, and the cam member 453d is rotatable about a rotation fulcrum shaft 453e connected to the rotation shaft of the cam drive motor M6. It has become. Therefore, when the cam member 453d is rotated by the cam drive motor M6 and the cam member 453d is positioned at the rotation position shown in FIG. 5A, the tip of the cleaning blade 451 is subjected to the secondary transfer by the urging force of the urging member 453c. It abuts on the peripheral surface of the roller 4. On the other hand, when the cam member 453d is positioned at the rotational position shown in FIG. 4B, the support member 453a is rotated clockwise in FIG. 4 against the urging force of the urging member 453c, and the tip of the cleaning blade 451 is turned on. Is separated from the peripheral surface of the secondary transfer roller 4. In this embodiment, a driver 314 is provided to drive the cam drive motor M6, and a drive signal corresponding to a command pulse given from the controller 310 is output to the cam drive motor M6 to release the cleaning blade 451. The contact is controlled as follows.

  FIG. 5 is a timing chart showing the separation contact operation of the cleaning blade. FIG. 6 is a diagram schematically illustrating the separation / contact operation of the cleaning blade. Hereinafter, the separation / contact operation of the cleaning blade 451 in the present embodiment will be described with reference to these drawings. In the present embodiment, the controller 310 controls the rotation / stop of the cam drive motor M6 based on the synchronization signal Vsync detected by the detection unit 92. That is, the secondary transfer roller 4 rotates and moves in the moving direction D4, and the synchronization signal is transmitted at the timing when the notch 911 of the detected portion 91 passes the detection position by the detection portion 92 as the secondary transfer roller 4 rotates. Vsync is output. At this time, the peripheral surface other than the concave portion 41 of the secondary transfer roller 4 is positioned at the CB separation contact position. However, when the transfer of the toner image to the nth transfer material S further proceeds, the concave portion 41 is separated from the CB. It moves to the contact position. At this time, gripping of the transfer material S by the gripping portion 44 disposed in the concave portion 41 is eliminated.

  When the concave portion 41 approaches the CB separation / contact position in this way, in this embodiment, the controller 310 rotates the cam drive motor M6 for a certain period of time before the concave portion 41 reaches the CB separation / contact position. The blade 451 is separated from the secondary transfer roller 4.

  Then, the controller 310 rotates the cam drive motor M6 for a predetermined time at the timing when the time t1 has elapsed from the output of the synchronization signal Vsync and the upstream end P3 of the recess 41 reaches the CB separation contact position. Accordingly, the cleaning blade 451 is moved to the secondary transfer roller at the timing Ton after the start of rotation of the cam drive motor M6 and before the downstream end of the transfer area TA (upstream end of the gripping area GA) reaches the CB separation contact position. 4 (FIG. 6A). In this embodiment, as shown in FIG. 3, the width of the cleaning blade 451 in the direction orthogonal to the moving direction D4, that is, the cleaning width, is shorter than the width of the secondary transfer roller 4 and the transfer material S. It is longer than the width of the toner, and it is possible to clean the fog toner.

  Due to this abutting operation, as shown by a thick broken line in FIG. 3, a contact mark is generated on the peripheral surface of the secondary transfer roller 4, and the transfer material S is gripped when the next transfer material S is gripped by the gripping portion 44. The contact mark is transferred to the surface. However, the contact mark position Pon to which the contact mark is transferred is the peripheral surface of the secondary transfer roller 4 in contact with the gripping area GA, that is, the area ARon, and the contact mark is transferred to the area ARon of the gripping area GA. Even so, it is cut by the cutting unit 200 as described above and removed to the collection box. Therefore, it is possible to reliably prevent the contact mark from being transferred to the transfer area TA and causing a deterioration in quality.

  Further, after timing Ton, the liquid developer adhering to the secondary transfer roller 4 is removed by cleaning by the cleaning blade 451. When the recess 41 approaches the CB separation contact position, the synchronization signal Vsync is output at the timing Tvs at which the cutout portion 911 of the detected portion 91 passes the detection position by the detection portion 92 again (FIG. 6 ( b)). The controller 310 rotates the cam drive motor M6 for a predetermined time at a timing when the time t2 has elapsed from the timing Tvs. As a result, the cleaning blade 451 is separated from the secondary transfer roller 4 at the timing Toff when the rear end (position P5) of the transfer area TA has passed the CB separation contact position (FIG. 6C). As shown by a thick broken line in FIG. 3, this separation operation causes separation stripes on the peripheral surface of the secondary transfer roller 4, but the separation stripe position Poff is an area ARoff that does not carry the transfer material S. The transfer material S is not affected by the separation stripe.

  As described above, in the present embodiment, the contact timing Ton of the cleaning blade 451 is controlled to generate contact marks in the area ARon of the gripping area GA as shown in FIG. Therefore, although the contact mark is transferred to the transfer material S, the transfer position is the gripping area GA, so that the printed matter (transfer area TA of the transfer material S) due to the contact mark can be reliably prevented. Thus, it is possible to reliably prevent the quality deterioration of the final printed matter.

  Further, the upstream side of the moving direction D4 (the right-hand side in FIG. 3) with respect to the peripheral surface (transfer material carrying region) of the secondary transfer roller 4 that contacts the transfer material S by controlling the separation timing Toff of the cleaning blade 451, That is, the cleaning blade 451 is separated from the secondary transfer roller in the area ARoff. Therefore, the separation streak is not transferred to the transfer material S, and the influence of the separation streak can be eliminated.

  Thus, in this embodiment, the intermediate transfer belt 31 corresponds to the “image carrier” of the present invention, the cleaning blade 451 corresponds to the “cleaning member” of the present invention, and the secondary transfer roller 4 corresponds to the present invention. Corresponds to “transfer roller”. Further, the separation contact cam mechanism 453 corresponds to the “operation part” of the present invention.

  FIG. 7 is a diagram showing an embodiment of an image forming system according to the present invention. The image forming system 400 is a system in which an image forming apparatus 410, a conveying apparatus 420, a cutting apparatus 430 having the same configuration as the above-described cutting unit 200, and a control apparatus 440 that controls each apparatus are combined. The image forming apparatus 410 includes a printing unit 411 having the same configuration as the printing unit 100 described above, and a transfer material stock unit 412 that temporarily stores the transfer material S to which the toner image is transferred by the printing unit 411. Yes. Then, at an appropriate timing, the transfer material S is transferred from the transfer material stock portion 412 to the cutting device 430 by the transfer device 420, and is cut into the grip area GA and the transfer area TA.

  In the image forming system 400 configured as described above, similarly to the image forming apparatus 1, the contact timing Ton and the separation timing Toff of the cleaning blade 451 are controlled, and the printed matter is soiled by the contact trace and the separation stripe. Is surely prevented. As a result, a printed matter can be created with high quality.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the cleaning unit 45 in which the cleaning blade 451 comes into contact with the peripheral surface of the secondary transfer roller 4 is used. However, the configuration of the cleaning unit is not limited to this. As shown in FIG. 8, a cleaning roller 454 may be used as a “cleaning member” of the present invention so as to be brought into contact with and separated from the peripheral surface of the secondary transfer roller 4. Note that reference numeral 455 in the figure is a blade that scrapes off the liquid developer collected by the cleaning roller 454.

  Further, in the above-described embodiment, the cleaning blade 451 is separated and brought into contact with the peripheral surface of the secondary transfer roller 4 using the separation / contact cam mechanism 453 shown in FIG. Needless to say, it may be abutted.

  DESCRIPTION OF SYMBOLS 1,410 ... Image forming apparatus, 4 ... Secondary transfer roller, 31 ... Intermediate transfer belt (image carrier), 41 ... Recess, 45 ... Cleaning part, 91 ... Detected part, 92 ... Detection part, 100, 411 ... Printing unit, 200 ... cutting unit, 300 ... control unit, 310 ... controller, 400 ... image forming system, 420 ... conveying device (conveying unit), 430 ... cutting device (cutting unit), 451 ... cleaning blade, 453 ... release Contact cam mechanism (operation part), 454 ... cleaning roller, D4 ... moving direction, GA ... gripping area, S ... transfer material, TA ... transfer area, Toff ... separation timing, Ton ... contact timing, Vsync ... synchronization signal

Claims (6)

An image carrier for carrying an image;
A transfer roller having a concave portion on a peripheral surface, a grip portion for gripping the transfer material in the concave portion, and a transfer roller for transferring the image carried on the image carrier to the transfer material gripped by the grip portion; ,
A cleaning member that contacts the transfer roller and cleans the peripheral surface of the transfer roller;
An operation unit for moving the cleaning member to a position in contact with or away from the peripheral surface of the transfer roller;
A cutting unit that cuts the transfer material onto which the image has been transferred by the transfer roller into a gripping region gripped by the gripping unit and a transfer region to which the image is transferred;
A control unit for bringing the cleaning member into contact with a position of a peripheral surface of the transfer roller in contact with the gripping region of the transfer material by the operation of the operation unit;
An image forming apparatus comprising:   The said control part operates the said operation part, The said cleaning member and the said transfer roller are spaced apart in the position of the surrounding surface different from the position of the surrounding surface of the said transfer roller which contact | abuts with the said transfer material. Image forming apparatus. An image carrier that carries an image, a grip portion that has a concave portion on the peripheral surface and grips a transfer material in the concave portion, and is carried by the image carrier on the transfer material gripped by the grip portion A transfer roller that transfers the image, a cleaning member that contacts the transfer roller to clean the peripheral surface of the transfer roller, and an operation unit that moves the cleaning member to a position that contacts or separates from the peripheral surface of the transfer roller An image forming unit comprising:
A transport unit that transports the transfer material onto which the image has been transferred in the image forming unit;
A cutting unit that cuts the transfer material transported by the transport unit into a gripping region gripped by the gripping unit and a transfer region to which the image is transferred;
A control unit for bringing the cleaning member into contact with a position of a peripheral surface of the transfer roller in contact with the gripping region of the transfer material by the operation of the operation unit;
An image forming system comprising:   The said control part operates the said operation | movement part, and separates the said cleaning member and the said transfer roller in the position of the surrounding surface different from the position of the surrounding surface of the said transfer roller which contact | abuts the said transfer material. Image forming system. Transport the transfer material,
Grasping the transferred transfer material with a gripping portion disposed in a recess formed on the peripheral surface of the transfer roller,
An image carried on an image carrier is transferred to the transfer material held by the holding unit with the transfer roller,
The transfer material onto which the image has been transferred is separated from the transfer roller and conveyed to a cutting unit,
Clean the peripheral surface of the transfer roller by bringing a cleaning member into contact with the peripheral surface of the peripheral surface of the transfer roller that is spaced apart from the transfer material and in contact with the gripping region gripped by the grip portion of the transfer material. In addition, the image forming method is characterized in that the cutting area of the transfer material and the transfer area to which the image is transferred are cut by the cutting section. The image forming method according to claim 5, wherein the cleaning member is separated from the transfer roller at a position different from a position of a circumferential surface that contacts the transfer material of the transfer roller.

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