JP2011107385A - Image forming method and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust an image forming device in an appropriate state by detecting a test image formed on a transfer belt, and to appropriately clean the test image after the detection. <P>SOLUTION: An image forming method is characterized by: detecting an image carried on an image carrier 40 by a detection means; rotating a transfer roller 61 that has a recessed part on its peripheral surface, forms a transfer nip by abutting on the image carrier 40 and separates from the image carrier 40, to allow the transfer roller 61 to separate from the image carrier 40; and moving the image carrier 40 so that the image carried on the image carrier 40 passes through a position where the transfer nip is formed, when the transfer roller 61 separates from the image carrier 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus for forming an image by transferring a toner image developed by a developing device onto a transfer material such as recording paper and fixing the toner image on the transfer material.

  Various image forming apparatuses that develop and visualize a latent image using a high-viscosity liquid developer in which a toner composed of a solid component is dispersed in a liquid solvent have been proposed. The developer used in this image forming apparatus has a solid content (toner particles) suspended in an organic solvent (carrier liquid) having an electrical insulating property made of silicon oil, mineral oil, edible oil, or the like. The toner particles are extremely fine with a particle diameter of around 1 μm. By using such fine toner particles, the wet image forming apparatus can achieve higher image quality than a dry image forming apparatus using powder toner particles having a particle diameter of about 7 μm.

  Conventionally, in an electrophotographic image forming apparatus using a liquid developer, a toner image formed on a developing unit is transferred to a transfer member, and then the transferred toner image is secondarily transferred to a transfer material such as recording paper. The image formation is performed. As the transfer member to which the toner image is transferred in the developing unit, a belt type or a roller type is used, and the surface of the transfer member is repeatedly used many times. For this reason, the surface of the transfer member after the secondary transfer is prepared for new image formation after the toner remaining after transfer is removed by a cleaning unit provided in contact with the transfer member.

  In such an image forming apparatus using a liquid developer, when the state of the liquid developer under development changes, the image finally transferred to the transfer material changes. For example, the image on the transfer material is affected by various conditions such as the concentration of toner particles in the liquid developer and the bias voltage from the photoconductor to the transfer member or from the transfer member to the secondary transfer member. In order to eliminate the influence of these various conditions and form an image on the transfer material stably, a test image (patch image) is formed on the transfer material or transfer member, and this test is performed using an optical system sensor or the like. Various image forming apparatuses have been proposed that perform adjustment processing for detecting image density and setting various conditions.

  As an image forming apparatus that performs adjustment processing using such a test image, Patent Document 1 discloses that a test image is formed on the surface of a recording sheet, the test image is detected by a density detection sensor, and the detected value is used. An image forming apparatus that replenishes toner in a developer tank is described. In Patent Document 2, a plurality of test images are formed while changing the development bias, the density of the test image is detected by a patch sensor, and the image density of the test image formed under an image forming condition in which the image density is saturated is obtained. Based on this, an image forming apparatus for obtaining an appropriate developer toner concentration is described. In the image forming apparatus described in Patent Document 2, the position for detecting the image density of the formed test image is performed not only on the photosensitive member but also on an intermediate transfer roller or a dedicated member for transferring the patch image. It has been proposed.

JP-A-9-114257 JP 2004-117666 A

  As described above, in the image forming apparatuses disclosed in Patent Document 1 and Patent Document 2, it is possible to perform high-quality image formation by adjusting the state of the liquid developer according to the formed test image. In the image forming apparatus described in Patent Document 1, it is necessary to provide a patch area on the recording paper in order to form a test image on the surface of the recording paper. On the other hand, the image forming apparatus described in Patent Document 2 does not require an extra patch area on the recording paper in order to form and detect a test image on various configurations used in the printing process such as a photoconductor. However, when test images formed on various configurations remain in the image forming apparatus, the inside of the apparatus may be contaminated and the quality of the image to be formed may be deteriorated. For this reason, test images formed on various configurations in the image forming apparatus need to be appropriately removed, but there is no description regarding removal of the test image, that is, cleaning.

  In order to solve the above-described problems, an image forming method according to the present invention has an image carrier carried an image, the image is detected by a detection means, and has a concave portion on a peripheral surface. A transfer nip is formed by contact, and a transfer roller separated from the image carrier is rotated to separate the image carrier from the transfer roller, and the image carrier and the transfer roller are separated from each other. Sometimes, the image carrier is moved so that the image carried on the image carrier passes through a position where the transfer nip is formed.

  Furthermore, the image forming method according to the present invention detects the rotational position of the transfer roller, and adjusts the position of the image carried on the image carrier based on the detected rotational position of the transfer roller. is there.

  Furthermore, in the image forming method according to the present invention, the image that has passed the position where the transfer nip is formed is cleaned by a cleaning unit that cleans the image carrier.

  Furthermore, in the image forming method according to the present invention, the cleaning unit includes a cleaning roller that is in contact with the image carrier and to which a bias is applied, and an application member that applies an application liquid to the cleaning roller. Is attached to the cleaning roller by an applied bias.

  The image forming apparatus according to the present invention has an image carrier that carries an image, a concave portion on the peripheral surface, forms a transfer nip in contact with the image carrier, and the peripheral surface is rotated by the rotation. The image is carried on the image carrier that passes through a position corresponding to the transfer nip when the transfer roller and the image carrier are separated by rotation of the transfer roller that is separated from the image carrier and the transfer roller. It has a control part which controls as mentioned above, and a detection means which detects the above-mentioned image.

  Furthermore, the image forming apparatus according to the present invention is formed on the latent image carrier, a latent image carrier that transfers an image to the image carrier, an exposure unit that forms a latent image on the latent image carrier, and the latent image carrier. A developing unit that develops the latent image, and the control unit controls the timing at which the exposure unit forms the latent image on the latent image carrier.

  Furthermore, the image forming apparatus according to the present invention includes a cleaning unit that cleans the image that has passed the position corresponding to the transfer nip.

  Furthermore, the image forming apparatus according to the present invention has a grip portion for gripping the transfer material in the concave portion.

  As described above, according to the image forming method and the image forming apparatus of the present invention, a test image is formed at the position of the image carrier where the concave portion of the transfer roller faces the transfer nip. It is possible to prevent the transfer roller from being contaminated. In addition, by cleaning the image carrier, it is possible to appropriately clean the image attached to the image carrier.

  Also, by arranging the gripping part that grips the transfer material in the concave part of the transfer roller, it is possible to arrange the gripping part with sufficient gripping force, positioning the transfer material accurately, and after gripping It is possible to prevent the deviation.

  Further, it is possible to efficiently collect an image on the image carrier by using a cleaning roller coated with a coating liquid in a cleaning unit for cleaning the image carrier.

1 is a diagram illustrating a main configuration of an image forming apparatus. The perspective view of a secondary transfer roller. Sectional drawing of a secondary transfer roller. The figure which shows operation | movement of the transfer material holding part of a secondary transfer roller. The figure which shows the mode of rotation of a secondary transfer roller. The figure which shows the mode of rotation of a secondary transfer roller (when a recessed part and a transfer belt oppose). The figure which shows the detail of a secondary transfer roller. The figure which shows the main structures of a cleaning apparatus. The schematic diagram which looked at the application roller and the dripping apparatus from the direction perpendicular to the axial direction. FIG. 3 is a block diagram illustrating control of the image forming apparatus. The figure which shows the mode of the test image formed on the transfer belt. The figure which shows the mode of the test image at the time of recessed part penetration. The figure which shows the mode of the test image at the time of a recessed part passage. The figure which shows an example of a test image (development patch). The figure which shows an example of a test image (exposure patch). The figure which shows an example of a test image (resist pattern). The figure which shows the main structures of the image processing apparatus which concerns on other embodiment.

  FIG. 1 is a diagram showing a main configuration of an image forming apparatus according to an embodiment of the present invention. The developing devices 30Y, 30M, 30C, and 30K as developing units are arranged below the image forming apparatus and transferred to the transfer belt 40 as an image carrier or transfer medium arranged in the center of the image forming apparatus. The components such as the secondary transfer unit 60 and a fixing unit (not shown) are arranged in the upper part of the image forming apparatus.

  Around the photosensitive members 10Y, 10M, 10C, and 10K as latent image carriers, exposure units 12Y, 12M, and 12C such as corona chargers 11Y, 11M, 11C, and 11K, and LED arrays are formed to form an image with toner. , 12K, etc. The photoconductors 10Y, 10M, 10C, and 10K are uniformly charged by the corona chargers 11Y, 11M, 11C, and 11K, and based on the input image signals by the exposure units 12Y, 12M, 12C, and 12K as exposure units. Then, an electrostatic latent image is formed on the charged photoreceptors 10Y, 10M, 10C, and 10K.

The developing devices 30Y, 30M, 30C, and 30K are roughly composed of developing rollers 20Y, 20M, 20C, and 20K as developer carriers, yellow (Y), magenta (M), cyan (C), and black (K). Developer containers (reservoirs) 31Y, 3 for storing liquid developers of respective colors
1M, 31C, 31K, anilox roller 32Y as a developer supply member that is a coating roller that applies liquid developers of these colors from developer containers 31Y, 31M, 31C, 31K to developing rollers 20Y, 20M, 20C, 20K, The electrostatic latent images formed on the photoconductors 10Y, 10M, 10C, and 10K are developed with liquid developers of various colors including 32M, 32C, and 32K.

  The primary transfer units 50Y, 50M, 50C, and 50K transfer images formed on the photoreceptors 10Y, 10M, 10C, and 10K to the photoreceptors 10Y, 10M, 10C, and 10K and primary transfer backup rollers 51Y, 51M, and 51C. , 51K, and a portion to be transferred to the transfer belt 40 through a nip portion.

  The transfer belt 40 is a belt formed of a seamless elastic member such as rubber. The transfer belt 40 is stretched between a belt driving roller 41 and a tension roller 42, and the photoreceptors 10Y and 10M are formed by primary transfer portions 50Y, 50M, 50C, and 50K. The belt drive roller 41 is rotationally driven while contacting with 10C and 10K. The primary transfer units 50Y, 5OM, 50C, and 50K are arranged such that the primary transfer backup rollers 51Y, 51M, 51C, and 51K face each other with the transfer belt 40 sandwiched between the photoreceptors 10Y, 10M, 10C, and 10K. The developed toner image of each color on the photoreceptors 10Y, 10M, 10C, and 10K is sequentially transferred onto the transfer belt 40 with the contact position with 10M, 10C, and 10K as the transfer position, and a full-color toner image is transferred. Form.

  The tension roller 42 stretches the transfer belt 40 together with the belt driving roller 41 and the like. A cleaning device 80 is brought into contact with the portion where the transfer belt 40 is stretched around the tension roller 42 so as to clean the remaining toner and the carrier on the transfer belt 40.

  The secondary transfer unit 60 includes a secondary transfer roller 61 as a means for transferring a toner image to a transfer medium. The secondary transfer roller 61 rotates in the direction indicated by the arrow so as to move along the moving direction of the transfer belt 40. Further, a transfer bias is applied to the secondary transfer roller 61, and the toner image on the transfer belt 40 is transferred to a transfer material such as paper, film, or cloth conveyed through the transfer material conveyance path L at the transfer nip. . The secondary transfer unit 60 includes a secondary transfer roller cleaning blade 62 that cleans the secondary transfer roller 61, a blade support member 63, and the like.

  A transfer material conveyance device (not shown) is arranged downstream of the secondary transfer unit 60 in the transfer material conveyance path L, and conveys the transfer material to a fixing unit (not shown). In the fixing unit, a single-color toner image or a full-color toner image transferred onto a transfer material such as paper is fused and fixed to the transfer material such as paper.

  The transfer material for the image forming apparatus is supplied by a paper feeding device (not shown). The transfer material set in such a sheet feeding device is sent to the transfer material conveyance path L one by one at a predetermined timing. In the transfer material transport path L, the transfer material is transported to the secondary transfer position by the gate rollers 101 and 101 ′ serving as the transfer material delivery unit and the transfer material guide 102, and a monochrome toner image formed on the transfer belt 40 A full color toner image is transferred to a transfer material.

The transfer material subjected to the secondary transfer is further transported to the fixing unit by the transfer material transport device as described above. The fixing unit is composed of a heating roller (not shown) and a pressure roller (not shown) biased to the side of the heating roller with a predetermined pressure. The single-color toner image or the full-color toner image transferred to the toner image is fused and fixed to a transfer material such as paper.

  Here, the developing device 30 will be described. Since the configurations of the peripheral portions of the photoconductors and the developing devices of the respective colors are the same, the peripheral portion of the photoconductor of yellow (Y) and the developing device 30Y will be described below.

  The peripheral portion of the photoconductor is along the rotation direction of the outer periphery of the photoconductor 10Y with the corona charger 11Y as a reference, the exposure unit 12Y, the developing roller 20Y of the developing device 30Y, the first photoconductor squeeze roller 13Y, and the second photoconductor. A squeeze roller 13Y ′, a primary transfer portion 50Y, a static eliminator (not shown) that neutralizes the potential of the photoconductor 10Y, and a photoconductor cleaning blade 18Y are provided. In the image forming process, it is defined that the configuration arranged in the earlier stage in the order of the corona charger 11Y to the photoreceptor cleaning blade 18Y is upstream from the configuration arranged in the subsequent stage.

  The photoconductor 10Y is a photoconductor drum formed of a cylindrical member having a photosensitive layer such as an amorphous silicon photoconductor formed on the outer peripheral surface, and rotates in a clockwise direction in FIG. The corona charger 11Y is disposed upstream of the nip portion between the photoconductor 10Y and the developing roller 20Y in the rotation direction of the photoconductor 10Y, and a voltage is applied from a power supply device (not shown) to corona-charge the photoconductor 10Y. The exposure unit 12Y is disposed downstream of the corona charger 11Y and upstream of the nip portion with the developing roller 20Y in the rotational direction of the photoreceptor 10Y, and emits light onto the photoreceptor 10Y charged by the corona charger 11Y. Irradiation forms a latent image on the photoreceptor 10Y.

  The developing device 30Y includes a developing roller 20Y that carries the liquid developer, an anilox roller 32Y that is a coating roller for applying the liquid developer to the developing roller 20Y, and a liquid developer amount that is applied to the developing roller 20Y. A regulating blade 33Y that regulates the liquid developer, an auger 34Y that supplies and supplies the liquid developer to the anilox roller 32Y, a compaction corona generator 22Y that puts the liquid developer carried on the developing roller 20Y into a compacted state, A developing roller cleaning blade 21Y that cleans the developing roller 20Y and a developer container 31Y that stores a liquid developer in a state where toner is dispersed in a carrier at a weight ratio of approximately 20%.

  The liquid developer contained in the developer container 31Y is a low-concentration (about 1 to 2 wt%) and low-viscosity volatile at room temperature using a conventionally used Isopar (trademark: exon) as a carrier. Is a non-volatile liquid developer having a high concentration and high viscosity and having non-volatility at room temperature. That is, in the liquid developer in the present invention, a solid having an average particle diameter of 1 μm in which a colorant such as a pigment is dispersed in a thermoplastic resin is introduced into a liquid solvent such as an organic solvent, silicon oil, mineral oil, or edible oil. Viscoelasticity at a shear rate of 1000 (1 / s) at 25 ° C. with a high viscosity (HAAKE RheoStress RS600) added with a dispersant and having a toner solid content concentration of about 20%. 30 to 300 mPa · s Liquid developer.

  Although the Y color developing device 30Y has been described in detail above, the other color developing devices 30M, 30C, and 30K have the same configuration. Note that the arrangement order and the number of members such as the photoconductor 20 and the developing device 30 corresponding to each color Y, M, C, and K are not limited to those shown in FIG. 1 and can be arbitrarily set. However, it may be constituted by a single color.

Next, the configuration of the secondary transfer roller 61 will be described. FIG. 2 is a view showing the secondary transfer roller 61 according to the embodiment of the present invention, and FIG. 3 is a cross-sectional view of the secondary transfer roller 61. FIG.
7 is a diagram showing a state of transfer material conveyance accompanying the rotation of the secondary transfer roller 61, and FIG. 8 is a diagram showing a state of operation of the transfer material gripping portion 610 accompanying the rotation of the secondary transfer roller 61. It is.

  2 and 3, reference numeral 601 denotes a roller base material, 602 denotes a roller shaft portion, 605 denotes a concave portion, 607 denotes an elastic member, 610 denotes a transfer material gripping portion, 611 denotes a gripping member, 612 denotes a gripping member receiving portion, and 640 denotes a transfer. A material peeling member 650 indicates a contact member.

  Roller shaft portions 602 are provided at both ends of the roller base material 601 of the secondary transfer roller 61, and are attached to the apparatus main body side so as to be rotatable about the roller shaft portions 602. Further, the roller base material 601 is provided with a concave portion 605 extending in the axial direction, and a transfer material gripping portion 610 is provided in the concave portion 605. The transfer material gripping part 610 is a mechanism for gripping or releasing the transfer material.

  An elastic member 607 that supports the transfer material is provided on the peripheral surface of the roller base material 601. The elastic member 607 is a member composed of a semiconductive elastic rubber layer having an electrical resistance component, and both ends thereof are fixed in the recess 605 while being wound around the roller base material 601. FIG. 3 shows how the elastic member 607 is fixed. One end of the elastic member 607 is fixed to the roller base material 601 by a fixing member 609a such as a screw together with a plate 608a extending in the axial direction. Similarly, the other end of the elastic member 607 is firmly fixed to the roller base member 601 by the plate 608b and the fixing member 609b. The fixing of the elastic member 607 to the roller base 601 is not limited to this, and other methods may be used.

  By winding the elastic member 607 around the transfer roller 40 in this way, it is possible to secure a wide width of the secondary transfer nip formed by the transfer roller 61 and the transfer belt 40 and to increase transfer efficiency. Further, since the fixing portion for fixing the elastic member 607 is disposed in the recess 605 of the transfer roller 61, it is not necessary to fix the elastic member 607 on the surface of the transfer roller 61, and the elastic member 607 can be easily replaced. It is possible to do.

  The roller shaft portion 602 of the secondary transfer roller 61 is rotatably supported by the frame member 671. The frame member 671 rotates and swings around a rotation support shaft portion 670 supported by the apparatus main body and is urged in a direction α indicated by an arrow by an urging member (not shown). Due to the urging force of the urging member, the secondary transfer roller 61 contacts the belt driving roller 41 with a constant load via the transfer belt 40.

  The transfer material gripping portion 610 is roughly composed of a pair of gripping members 611 and gripping member receiving portions 612 that are discretely provided in the roller axial direction, and a plurality of transfers that are appropriately arranged between the pair in the roller axial direction. The material peeling member 640 is comprised. All the gripping members 611 are configured to be movable, and operate to sandwich the transfer material with the gripping member receiving portion 612 to grip the transfer material or between the gripping member receiving portion 612. The transfer material can be released by operating at intervals. Further, all the transfer material peeling members 640 operate so as to push out the transfer material held by the holding member 611 and the holding member receiving portion 612 in a direction away from the secondary transfer roller 61 side.

  The operation of the transfer material gripping part 610 will be described in more detail with reference to FIG. FIG. 4 is a view of each configuration of the transfer material gripping portion 610 schematically shown from the axial direction. 4A, FIG. 4B, FIG. 4C, and FIG. 4D show the states of the transfer material gripping portion 610 in the secondary transfer roller 61 of FIG. 6 schematically shows an operation state that the transfer material gripping part 610 takes when the transfer material gripping part 610 of the secondary transfer roller 61 comes to the position marked as C or D.

  FIG. 4A shows a state where the secondary transfer roller 61 is rotating without gripping the transfer material by the transfer material gripping portion 610. At this time, the gripping member 611 and the transfer material peeling member 640 are configured to fit within the outermost periphery when the secondary transfer roller 61 is viewed as a cylinder. This shows a state when the transfer material gripping portion 610 exists in the range of A in FIG. 1 during the rotation process of the secondary transfer roller 61.

  4B, the gripping member 611 moves in the direction (a) to form a predetermined space with the gripping member receiving portion 612, and the transfer material S entering the space is gripped by the gripping member 611 and the gripping member 611. It is a figure which shows the state which is preparing to clamp with the part receiving part 612. FIG. In the rotation process of the secondary transfer roller 61, the transfer material gripping portion 610 comes to the position B in FIG. 1 and enters along the transfer material guide 102 along with the rotation of the gate rollers 101 and 101 ′. The state which is preparing the holding | grip of a transfer material is shown.

  FIG. 4C shows a state in which the transfer material S that has entered the space is sandwiched between the gripping member receiving portion 612 as the gripping member 611 moves in the (a ′) direction. At this time, the transfer material S gripped at one end by the transfer material gripping portion 610 is wound around the roller base material 601 of the secondary transfer roller 61 as the secondary transfer roller 61 rotates. As described above, since the transfer material S is held and fixed by the transfer material holding portion 610 before the transfer material enters the secondary transfer nip, the transfer material S to which the toner image is transferred can be positioned accurately. . In the rotation process of the secondary transfer roller 61, when the transfer material gripping portion 610 is positioned in the range C in FIG. 1, the state shown in FIG. 4C is maintained.

  4D, the gripping member 611 moves in the direction (a) to form a predetermined space with the gripping part receiving portion 612 to release the transfer material S, and the transfer material peeling member 640 has (b). It shows a state where the transfer material S is pushed in the direction away from the secondary transfer roller 61 by moving in the direction. In this operation state, in the rotation process of the secondary transfer roller 61, the transfer material gripping portion 610 comes to the position D in FIG. 1 and the transfer material S on which the toner image is transferred through the secondary transfer nip is moved to the next. This is for delivery to the transfer material transport process.

  As described above, the transfer material gripping unit 610 grips the transfer material S before the transfer material S is inserted between the secondary transfer nips of the transfer belt 40 and the secondary transfer roller 61, and The operation is to release the gripped transfer material S after being inserted between the secondary transfer nips with the transfer roller 61. The transfer material S that has passed through the secondary transfer nip reliably separates the transfer material S from the secondary transfer roller 61 when the transfer material gripping portion 610 operates as shown in FIG. It can be reliably guided to the material transport process. In general, in an image forming process using a liquid developer, the transfer material S on which the toner image is transferred at the secondary transfer nip is attached to either the secondary transfer roller 61 or the transfer belt 40. Although peeling may be difficult, the transfer material S can be reliably peeled off from each component by the operation of FIG. 4D by the transfer material gripping mechanism 610.

  Next, a structure for restricting the position between the secondary transfer roller 61 and the belt drive roller 41 while the secondary transfer roller 61 provided with the recess 605 applies a predetermined pressure at the secondary transfer nip. explain. 5 and 6 are diagrams for explaining the operation of the secondary transfer unit 60 in the image forming apparatus according to the embodiment of the present invention. In any of the drawings, (A) is a view of the secondary transfer unit 60 as viewed from the side of the apparatus, and (B) is a diagram showing a schematic cross section of the secondary transfer unit 60. FIG. 5 and 6, 650 is a contact member, 670 is a rotation support shaft portion, 671 is a frame member, 672 is an urging member, 689 is a roller shaft portion of the belt drive roller 41, and 690 is a support member. ing.

In the secondary transfer unit 60, the roller shaft portion 602 of the secondary transfer roller 61 is rotatably attached to the frame member 671 at both ends thereof. Further, the frame member 671 is rotatable about the rotation support shaft portion 670 and is urged by the urging member 672 in the direction of the arrow in the figure. With such a structure, the secondary transfer roller 61 is biased toward the belt driving roller 41 so that a predetermined pressure can be applied to the secondary transfer nip between the belt driving roller 41 and the secondary transfer roller 61. It has become. By such transfer pressure and transfer bias in the secondary transfer nip, the toner particles on the transfer belt 40 are efficiently transferred to the transfer material side in the secondary transfer nip.

  Abutting members 650 are provided at both ends of the roller shaft portion 602 of the secondary transfer roller 61, respectively. Support members 690 are respectively provided at both ends of the roller shaft portion 689 of the belt drive roller 41 so as to correspond to the contact member 650. As shown in FIGS. 5 and 6B, the contact member 650 and the support member 690 are disposed so that the positions in the axial direction are aligned.

  FIG. 7 shows configurations of the contact member and the support member according to the embodiment of the present invention. The contact member 650 has a shape as shown in the figure, and is provided with a contact surface 663 whose distance from the rotation center O of the secondary transfer roller 61 is R2. On both sides of the contact surface 663, a first delivery surface 661 for suppressing an impact when starting to contact the support member 690 with the belt driving roller 41 and an impact when separating from the non-contact member 690 are suppressed. A second delivery surface 662 is formed.

  The contact surface 663 is provided corresponding to a region (contact region C3) where the concave portion 605 is opened in the secondary transfer roller 61 when viewed from the roller axial direction. When the concave portion 605 is disposed so as to face the belt driving roller 41 (or the transfer belt 40) in accordance with the operation of the apparatus, the contact surface 663 (contact region C3) is connected to the support member 690 on the belt driving roller 41 side. By the contact, the support member 690 receives the urging pressure of the secondary transfer roller 61, and the distance and the positional relationship between the secondary transfer roller 61 and the belt driving roller 41 are maintained.

  In this embodiment, the sum of the radius R1 of the secondary transfer roller and the radius r1 of the belt driving roller 41 is substantially equal to the sum of the radius R2 at the contact surface 663 of the contact member 650 and the radius r2 of the support member 690. It is set to be. With such a configuration, even when the concave portion 605 of the secondary transfer roller 61 is opposed to the belt driving roller 41, the contact member 650 and the support member 690 are in contact with each other, and the virtual circumference that connects both ends of the concave portion 605 is exactly the same. As in the case where the peripheral length B of the surface is provided, the positional relationship between the secondary transfer roller 61 and the belt driving roller 41 can be maintained.

  In the present embodiment, first, the nip width formed when the secondary transfer roller 61 and the transfer belt 40 contact each other is the width in the rotation direction of the concave portion 605 of the secondary transfer roller 61, that is, the circumference of the virtual circumferential surface. The condition is that it is smaller than the length B. Under such conditions, a period during which the transfer belt 40 is separated from the secondary transfer roller 61 can be generated when the secondary transfer roller 61 rotates.

  Further, the conveyance interval between a certain transfer material and the next transfer material is transferred by the elastic member 605 disposed on the surface of the secondary transfer roller 61 so that the image on the transfer belt 40 is reliably transferred to the transfer material. Thus, it is set to be larger than the virtual circumferential length B of the recess 605.

Here, a method for measuring the nip width formed by the contact between the secondary transfer roller 61 and the transfer belt 40 will be described. First, the two-component curing for mold forming is performed on the portion of the secondary transfer roller 61 where the nip is formed. Type silicone rubber is applied, belt drive roller 41 and secondary transfer roller 61
And the silicone rubber is cured with the nip formed. In the present embodiment, an injection type exafine (manufactured by GC Corporation) was used as the two-component curable silicone rubber. Subsequently, the cured silicone rubber is taken out from the nip portion, and the width of the nip forming portion (the portion where the silicon rubber is thinned) is measured using a caliper.

  The support member 690 is a member having an outer periphery whose distance from the roller rotation center O ′ of the belt driving roller 41 is r2, and the contact surface is lubricated in order to suppress resistance at the time of contact with the contact member 690. A sliding portion such as a bearing that is rotated is provided. As each roller rotates, the secondary transfer roller 61 and the belt drive roller 41 receive the load of the secondary transfer roller 61 that is in contact with the contact surface 663 of the contact member 650 and biased by the biasing member 672. The distance and the positional relationship between them are maintained.

  The secondary transfer unit 60 repeats the state shown in FIG. 5 → the state shown in FIG. 6 → as the rollers rotate. FIG. 5 shows a state where the recess 605 does not face the belt driving roller 41 (or the transfer belt 40). At this time, the urging force from the urging member 672 is applied to the secondary transfer nip, a predetermined transfer pressure is ensured, and further, between the secondary transfer roller 61 and the belt driving roller 41. An appropriate transfer bias is applied, and the toner particles on the transfer belt 40 are transferred to the transfer material side at the secondary transfer nip. In this state, the abutting member 650 and the support member 690 are completely separated from each other, and position restriction by them is not working.

  FIG. 6 shows a state where the recess 605 faces the belt driving roller 41 (or the transfer belt 40). At this time, the contact surface 663 (contact region C3) of the contact member 650 is in contact with the support member 690, and the biasing pressure of the secondary transfer roller 61 biased by the biasing member 672 is supported. The member 690 receives and the distance and positional relationship between the secondary transfer roller 61 and the belt drive roller 41 are maintained.

  According to the present embodiment described above, the secondary transfer roller 61 is biased toward the belt driving roller 41, but the shaft portion of the secondary transfer roller 61 has the contact member 650, and the belt driving roller Since the support member 690 is disposed on the shaft portion 41, when the concave portion 605 faces the transfer belt, that is, when the concave portion 605 and the transfer belt 40 are not in contact with each other, the secondary transfer roller 61 And the belt drive roller 41 can be maintained in a positional relationship.

  Next, the cleaning device 80 for cleaning the surface of the transfer belt 40 will be described in more detail. FIG. 8 is a view showing an outline of a cleaning device used in the image forming apparatus according to the embodiment of the present invention. In FIG. 8, 81 is a cleaning roller, 811 is a cleaning roller cleaning blade, 82 is a transfer member cleaning blade, 83 is an application roller, 831 is a sponge outer peripheral part, 85 is a leveling roller, 88 is a tank, 881 is a tank receiving part, Reference numeral 882 denotes a tank storage section.

  The cleaning roller 81 is disposed so as to face the tension roller 42 with the transfer belt 40 interposed therebetween, and contacts the transfer belt 40 to clean the surface of the transfer belt 40. The cleaning roller 81 is made of conductive urethane rubber as a material, and the surface layer is coated with a conductive urethane coat to reduce the surface roughness.

A bias voltage is applied to the cleaning roller 81 by a bias applying unit 86. In the present embodiment, an electric field is formed between the cleaning roller 81 and the tension roller 42 by applying a predetermined negative voltage to the cleaning roller 81 and grounding the tension roller 42. Toner particles charged on the positive side
This electric field attracts the cleaning roller 81, and the cleaning roller 81 can efficiently collect the toner particles on the transfer belt 40.

  Further, the bias applying unit 86 of the present embodiment can change the bias applied to the cleaning roller 81 by the control of the control unit, and the state and amount of the toner particles on the transfer belt 40 to be cleaned. It is possible to change appropriately according to. More specifically, by setting the absolute value of the bias applied to the cleaning roller 81 by the bias applying unit 86 to be large, the electric field formed between the tension roller 42 and the cleaning roller 81 is increased, so that the toner The recovery efficiency can be increased.

  The cleaning roller cleaning blade 811 is an elastic blade having a rubber portion made of urethane rubber or the like that comes into contact with the surface of the cleaning roller 81. The cleaning roller 811 comes into contact with the cleaning roller 81 and scrapes off the toner particles and the carrier liquid on the cleaning roller 81. To clean. The recovered material 1 scraped off by the cleaning roller cleaning blade 811 contains more toner particles than the recovered material 2 recovered by the transfer belt cleaning blade 82 described later.

  The recovered material 1 scraped off by the cleaning roller cleaning blade 602 falls to the tank receiving portion 881 of the tank 88 and is finally stored in the tank storage portion 882.

  The transfer belt cleaning blade 82 is disposed to face the tension roller 42 with the transfer belt 40 interposed therebetween. The transfer belt cleaning blade 82 is constituted by an elastic blade having a rubber portion made of urethane rubber or the like that comes into contact with the surface of the transfer belt 40 and scrapes off the carrier liquid remaining on the transfer belt 40 cleaned by the cleaning roller 81. To clean. The recovered material 2 scraped off by the transfer belt cleaning blade 82 falls to the tank receiving portion 881 of the tank 88 and is stored in the tank storage portion 882, like the recovered material 1.

  The application roller 83 is a roller for applying the carrier liquid to the cleaning roller 81, and in this embodiment, a sponge member (sponge outer peripheral part 831) is arranged on the outer peripheral part thereof. The cleaning roller 81 to which the carrier liquid is applied by the application roller 83 is damp, and the carrier liquid is sufficiently interposed in the nip portion with the transfer belt 40 (tension roller 42). In such a state, a bias voltage that attracts toner particles in the liquid developer is applied to the cleaning roller 81, so that a good cleaning property can be obtained.

  A configuration in which the carrier liquid is dropped and supplied to the coating roller 604 is a dropping device 84, and a nozzle 841 for discharging the carrier liquid is provided below the dropping device 84. FIG. 9 is a schematic view of the application roller 83, the dropping device 84, and the leveling roller 85 as seen from the direction perpendicular to the roller axial direction. The nozzles 841 of the dropping device 84 are provided at substantially equal intervals in the axial direction, and the carrier liquid is supplied to the coating roller 83 directly below the nozzles 841.

  The application roller 83 that has received the supply of the carrier liquid rotates counterclockwise as shown in FIG. 8 and moves toward the leveling roller 85, and the sponge outer peripheral portion 831 is pressed by the leveling roller 85, The carrier liquid in the sponge outer peripheral portion 831 spreads in the axial direction of the application roller 83.

Next, control of the image forming apparatus according to the present invention will be described. FIG. 10 is a diagram showing an outline of a control block in the image forming apparatus according to the embodiment of the present invention. In FIG. 10, 15
0 is a main control unit, 160 is a secondary transfer roller control unit, 162 is a belt drive roller control unit, 163 is a cleaning device control unit, 164 is an image forming unit control unit, 900 is a position detection unit, 901 is a detected member, Reference numeral 891a denotes a slit, 902 denotes a sensor, 903 denotes a sensor support member, and 43 denotes a detection sensor.

  The main control unit 150 is a main controller for performing each control of the image forming apparatus according to the present invention. As such a main control unit 150, a general-purpose information processing apparatus including a CPU, a RAM, a ROM, and the like is used, and a program for causing the CPU to execute an operation of outputting a command to a predetermined block based on input predetermined information Can be realized by storing in advance in the ROM.

  The belt driving roller control unit 162 starts and stops the rotation of the belt driving roller 41 and controls the rotational peripheral speed based on a control command from the main control unit 150, and transfers the belt wound on the belt driving roller 162. Control relating to movement of the belt 40 is performed.

  Based on the control command from the main control unit 150, the secondary transfer roller control unit 160 rotates the peripheral speed of the secondary transfer roller 61, the operation timing of the transfer material gripping unit 611 in the transfer material gripping mechanism 610, and the transfer material. The operation timing of the peeling member 640 is controlled. Further, the rotation reference position of the secondary transfer roller 61 detected by the rotation position detection unit is transmitted to the main control unit 150 and used for various controls. By such a secondary transfer roller control unit 160, it is possible to freely change the timing of gripping the transfer material by the transfer material gripping mechanism 610 or the timing of releasing the transfer material.

  The detection sensor 43 (detection means) irradiates the test image formed on the transfer belt 40 with light, detects the reflected light to detect the state of the test image, and outputs an image detection signal to the main control unit 150. To do. In the present embodiment, the detection sensor 43 is disposed in a portion wound around the belt driving roller 41, so that the test image is detected in a stable state without the transfer belt 40 flapping. The arrangement position of the detection sensor 43 is not limited to this embodiment, and an appropriate position can be selected as long as the test image before cleaning on the transfer belt 40 can be detected.

  The image forming unit control unit 164 controls each color image forming unit including the photoconductor 10 and the developing device 30. Specifically, the concentration of the liquid developer stored in the developer container 31, the charged state of the photosensitive member by the corona charger 11, the developing bias that is a potential difference between the photosensitive member 10 and the developing roller 20 are controlled. Thus, the state of the toner image formed on the photoconductor 10 is adjusted. Also, it is possible to adjust the resist by controlling the exposure timing in the exposure unit 12 of each color image forming unit. In the adjustment process using the test image in the present embodiment, the adjustment is executed so that the image formed by the image forming apparatus is optimized by the image detection signal output from the exposure sensor 43.

  The position detection unit 900 is a member arranged to detect the rotation position of the secondary transfer roller 61, detects the rotation reference position of the secondary transfer roller 61, and detects the position with respect to the main control unit 150. Output a signal. In the present embodiment, the apparatus includes a detected member 901, a slit 901a, a sensor 902, and a sensor support member 903.

  The detected member 901 is a circular member that is fixed to the roller shaft portion 602 of the secondary transfer roller 61 and rotates together with the secondary transfer roller 61. The sensor 901 is fixed to the image forming apparatus main body side and is disposed so as not to rotate together with the secondary transfer roller 61. In the sensor 901, the light emitting part and the light receiving part are arranged at positions where the detected member 901 is opposed to each other.

  The slit 891a provided in the detection member 901 is configured to pass between the light emitting unit and the light receiving unit as the secondary transfer roller 61 rotates, and the light receiving unit is separated from the light emitting unit when passing through the slit 901a. The light receiving unit is turned on when receiving radiated light, and when not passing, the light receiving unit is turned off. In the present embodiment, the reference position of the secondary transfer roller 61 can be detected by a position detection signal output from the position detection unit 900 using such an optical system. The detection of the reference position is not limited to such a form, and an appropriate form such as using mechanical detection means can be employed.

  The cleaning device control unit 163 is a means for controlling the cleaning device 80 provided for cleaning the transfer belt 40, specifically, the rotation driving of the coating roller 83 and the cleaning roller 81, and the dropping device 84. The amount of carrier liquid dropped from the nozzle 841 and the bias amount for the bias applying unit 86 are controlled. In particular, in the present embodiment, the absolute value of the bias applied to the bias applying unit 86 at the time of cleaning is set to be larger than that at the time of normal printing so that the toner remaining on the transfer belt 40 can be efficiently collected. I have control.

  Next, test image formation in the present embodiment will be described in detail with reference to FIGS. FIG. 11 is a diagram illustrating a state of the test image formed on the transfer belt 40, and FIG. 12 is a diagram illustrating the state of the test image when the concave portion 605 of the secondary transfer roller 61 enters, FIG. FIG. 6 is a diagram showing a state of a test image when the secondary transfer roller 61 passes through a recess 605.

  FIG. 11 is a diagram illustrating a test image formed on the transfer belt 40. In this embodiment, it is possible to form a test image and perform adjustment processing during normal printing. However, adjustment processing that only forms a test image may be executed. In the figure, it can be seen that images P1, P2 used for normal printing, that is, transferred to a transfer material, and a test image formed between the images P1, P2 are formed on the transfer belt 40. These images P1 and P2 and the test image are toner images transferred onto the transfer belt 40 by the color photoreceptors 10 respectively.

  In the present embodiment, the detection sensor 43 is disposed at a position where the transfer belt 40 is wound around the belt driving roller 41. At such a position, the test image formed on the transfer belt 40 can be detected in a stable state without the transfer belt 40 flapping. The position of the detection sensor 43 is not limited to such a position, and may be disposed at a position indicated by 43 ′ in the drawing, for example.

  The test image formed on the transfer belt 40 has a length D along the moving direction of the transfer belt 40 as D. The length D of this test image is shorter than the virtual circumferential length B of the recess 605 of the secondary transfer roller 61. By selecting the test image to such a length, when the test image moves to the vicinity of the secondary transfer portion, the test image can be stored in the concave portion 605, and the test image is attached to the secondary transfer roller 61. I will not let you.

FIG. 12 is a view showing a state where the movement of the transfer belt 40 and the rotation of the secondary transfer roller 61 are further advanced from the state of FIG. 11, and a state where the test image enters the recess 605. is there. The test image 1 detected by the detection sensor 42 is transferred by the transfer belt 40 and enters the recess 605 of the secondary transfer roller 61. The leading end of the test image 1 is located near one end of the recessed portion 605 that is being separated, and does not adhere to the secondary transfer roller 61. In order to form such a test image, an accurate formation timing of the test image is required. Therefore, in this embodiment, the rotational position of the secondary transfer roller 61 detected by the position detection unit 900 described with reference to FIG. 11 is used to measure the timing for forming a test image.

  FIG. 13 is a view showing a state where the movement of the transfer belt 40 and the rotation of the secondary transfer roller 61 are further advanced from the state of FIG. 12, and a state where the test image has passed through the recess 605. is there. The rear end portion of the test image 1 is located near the other end of the recessed portion 605 that is being separated, and does not adhere to the secondary transfer roller 61. In this way, the test image is passed through the recess 605 by making the length D of the test image shorter than the virtual circumference B of the recess 605 and appropriately timing the test image formation. It is possible to prevent the transfer roller 61 from being contaminated with the test image.

  The test image is moved by the transfer belt 40 and cleaned by the cleaning device 80 described with reference to FIG. Unlike the normal cleaning of the transfer belt 40, the test image contains a large amount of toner particles. Therefore, when the test image passes through the cleaning device 80, the absolute value of the bias applied by the bias applying unit 86. It is good also as raising a cleaning capability by enlarging.

  FIG. 13 shows a state in which the image P2, the test image 2, and the image P3 are formed on the transfer belt 40 after the test image 1. The images P2 and P3 used for normal printing are transferred to the transfer material. However, the test image 2 is not transferred to the transfer material as in the case of the test image 1, and the secondary transfer is performed. It is transferred by the transfer belt 40 without adhering to the roller 61 and cleaned by the cleaning device 80. The distance L in the moving direction of the transfer belt 40 from the leading end of the test image 1 to the leading end of the test image 2 is substantially equal to the moving distance in the circumferential direction when the secondary transfer roller 61 makes one rotation. . With such a distance, a test image can be formed every time the secondary transfer roller 61 rotates.

  As described above, in the present embodiment, by using the concave portion 605 of the secondary transfer roller 61, it is possible to execute the adjustment process for optimizing the image forming apparatus while forming a test image during normal printing. . In addition, the length D of the test image is made shorter than the virtual circumference B of the recess 605 and the test image formation timing is appropriately measured, so that the test image is passed through the recess 605 and the secondary transfer roller 61. It is possible to prevent contamination.

  Next, various embodiments of the test image will be described with reference to FIGS. 14 to 16. FIG. 14 is a diagram illustrating an example of a test image (development patch) used when adjusting the development bias and the density of the liquid developer. Six solid images are formed along the moving direction of the transfer belt 40. These six solid images are all solid images of K color, and the formation conditions in the image forming unit are different for each solid image. By detecting solid images with different formation conditions by the detection sensor 43, the image forming unit can be suitably adjusted. Similarly, six solid images are formed for each of the other colors Y, M, and C, and the image forming unit for each color is suitably adjusted.

  In the present embodiment, the length D of one solid image in the transport direction of the transfer belt 40 is 100 [mm], which is shorter than the virtual circumferential length B (113 [mm]) of the recess 605 of the secondary transfer roller 61. Is set. Further, the distance L between the tips of the solid images is set to be approximately equal to the circumferential movement distance when the secondary transfer roller 61 rotates once, and a solid image is formed every time the secondary transfer roller 61 rotates. Is done.

FIG. 15 is a diagram showing an example of a test image (exposure patch) used for measuring the resolution of an image to be formed. By forming such a test image and detecting it by the detection sensor 43, the exposure intensity with respect to the photoreceptor 10 and the charging potential in the image forming unit are adjusted. Four images are formed along the moving direction of the transfer belt 40. Each of these four images is a set of fine lines formed in K color. Similarly, four solid images are formed for the other colors of Y, M, and C, and the image forming section for each color is suitably adjusted.

  In this embodiment, the length D in the transport direction of the transfer belt 40 is 44.2 [mm] and the virtual circumferential length B (113 [mm] of the concave portion 605 of the secondary transfer roller 61 for one thin line set image. ) Is set shorter.

  FIG. 16 is a diagram showing an example of a test image (resist pattern) used for correcting a deviation in exposure timing of an image to be formed and a deviation in an image formed in each color image forming unit. It is composed of nine solid images arranged in order from the upstream in the conveying direction of the transfer belt 40.

  In the subscripts (K1, K2, Y1, Y2, C1, C2, M1, M2) attached to each solid image, the alphabet indicates the formation color of the solid image, and the number indicates the shape of the solid image. Show. The shape of the first solid image is a rectangular shape perpendicular to the conveyance direction of the transfer belt 40, and the shape of the second solid image is a rectangular shape having a predetermined inclination angle with respect to the conveyance direction of the transfer belt 40. It has become. The deviation in the main scanning direction (the horizontal direction in the figure) is measured by the distance between the adjacent first solid image and second solid image of the same color. Further, the deviation in the sub-scanning direction (vertical direction in the figure) is measured by the distance between the first solid images of different colors.

  In this embodiment, the length in the conveyance direction of the transfer belt 40 is L1 for one resist pattern. For such a resist pattern, by setting the length L1 to be shorter than the virtual circumference B of the concave portion 605 of the secondary transfer roller 61, the resist pattern can be accommodated in the concave portion 605. Contamination of the transfer roller 61 can be prevented.

  Next, another embodiment of the present invention will be described. FIG. 17 is a diagram showing main components constituting an image forming apparatus according to another embodiment of the present invention. The components denoted by the same reference numerals as those in the previous embodiment are the same components and will not be described in detail. In the previous embodiment, the transfer belt 40 is used as the image carrier, but in this embodiment, a transfer roller 96 (image carrier drum) is used as the image carrier. Further, the transfer roller 96 is provided with a cleaning device 80 similar to the one that cleans the transfer belt 40 in the left embodiment, on the downstream side of the secondary transfer nip.

  On the transfer roller 96, yellow (Y), magenta (M), cyan (C), and black (K) toner images are formed by the developing devices 30Y, 30M, 30C, and 30K. The secondary transfer roller 61 is biased toward the transfer roller 96 by a mechanism (not shown) so that a predetermined pressure is obtained at the nip portion between the transfer roller 96 and the secondary transfer roller 61. The test image formed on the transfer roller 96 by the developing device 30 is detected by the detection sensor 43 positioned between the photoconductor 10K and the secondary transfer nip. The detection sensor may be disposed between the secondary transfer nip and the cleaning device 80 as indicated by reference numeral 43 ′. Also in the present embodiment, when the transfer roller 96 and the secondary transfer roller 61 are separated from each other, the test image carried on the transfer roller 96 passes through the position where the secondary transfer nip is formed, so that the secondary image is transferred. It is possible to prevent the transfer roller 61 from being contaminated with the test image.

As in the previous embodiment, a contact member 650 is provided at each end of the secondary transfer roller 61, and a support member 690 is provided at each end of the transfer roller 96. When the concave portion 605 of the secondary transfer roller 61 faces the transfer roller 96 side, that is, when the peripheral surface of the secondary transfer roller 61 is separated from the transfer roller 96, the contact member 650 and the support member 690 come into contact with each other. The positional relationship between the secondary transfer roller 61 and the transfer roller 96 can be maintained.

  As described above, even in the embodiment in which the roller (transfer roller 96) is used as the transfer member, it can be easily estimated that the same effects as those in the embodiment in which the transfer belt 40 introduced above can be obtained. .

  Note that although various embodiments have been described in this specification, embodiments configured by appropriately combining the configurations of the respective embodiments are also included in the scope of the present invention.

  10Y, 10M, 10C, 10K ... photosensitive bodies (latent image carriers), 11Y, 11M, 11C, 11K ... corona chargers, 12Y, 12M, 12C, 12K ... exposure units, 13Y, 13M, 13C, 13K ... first Photoconductor squeeze roller, 13Y ', 13M', 13C ', 13K' ... Second photoconductor squeeze roller, 14Y, 14Y ', 14M, 14M', 14C, 14C ', 14K, 14K' ... Photoconductor squeeze roller cleaning blade , 18Y, 18M, 18C, 18K ... Photoconductor cleaning blade, 20Y, 20M, 20C, 20K ... Developing roller, 21Y, 21M, 21C, 21K ... Developing roller cleaning blade, 22Y, 22M, 22C, 22K ... Compact corona generator , 30Y, 30M, 30C, 30K ... Developer , 31Y, 31M, 31C, 31K ... developer container, 32Y, 32M, 32C, 32K ... anilox roller, 33Y, 33M, 33C, 33K ... regulating blade, 34Y, 34M, 34C, 34K ... auger (supply roller), 40 ... transfer belt, 41 ... belt drive roller, 42 ... tension roller, 43 ... detection sensor, 50Y, 50M, 50C, 50K ... primary transfer section, 51Y, 51M, 51C, 51K ... primary transfer backup roller, 60 ... 2 Secondary transfer unit 61 ... Secondary transfer roller 62 ... Secondary transfer roller cleaning blade 63 ... Blade support member 64 ... Secondary transfer unit collection and storage unit 96 ... Transfer roller 101 ... Gate roller 102 ... Transfer material Guide, 150 ... main control unit, 160 ... secondary transfer roller control unit, 62 ... Belt drive roller control unit, 163 ... Cleaning device control unit, 164 ... Image forming unit control unit, 601 ... Roller base material, 602 ... Roller shaft, 605 ... Concave portion, 607 ... Elastic member, 608 ... Plate, 609 ... Fixing member, 610 ... transfer material gripping part, 611 ... gripping member, 612 ... gripping member receiving part, 640 ... transfer material peeling member, 650 ... abutting member, 661 ... first delivery surface, 662 ... second delivery surface, 663 ... Abutting surface, 670 ... Rotating support shaft part, 671 ... Frame member, 672 ... Biasing member, 690 ... Support member, 80 ... Cleaning device, 84 ... Drip device, 841 ... Nozzle, 83 ... Coating roller, 85 ... Leveling roller, 831 ... Sponge outer periphery, 811 ... Cleaning roller cleaning blade, 82 ... Transfer member cleaning blade, 86 ... Bar Ias applying unit, 88 ... tank, 881 ... tank receiving unit, 882 ... tank storage unit, 900 ... position detecting unit, 901 ... detected member, 901a ... slit, 902 ... sensor, 903 ... sensor support member

Claims (8)

The image carrier carries the image,
The image is detected by a detection means,
The peripheral surface has a recess, forms a transfer nip by contacting the image carrier, rotates the transfer roller that is separated from the image carrier, and separates the image carrier and the transfer roller,
Moving the image carrier so that the image carried on the image carrier passes through the position where the transfer nip is formed when the image carrier and the transfer roller are separated from each other; An image forming method. Detecting the rotational position of the transfer roller;
The image forming method according to claim 1, wherein the position of the image carried on the image carrier is adjusted based on the detected rotational position of the transfer roller.   The image forming method according to claim 1, wherein the image that has passed through the position where the transfer nip is formed is cleaned by a cleaning unit that cleans an image carrier. The cleaning unit includes a cleaning roller that is in contact with the image carrier and to which a bias is applied, and an application member that applies an application liquid to the cleaning roller.
The image forming method according to claim 3, wherein the image is attached to the cleaning roller by an applied bias. An image carrier for carrying an image;
A transfer roller having a recess on the peripheral surface to form a transfer nip in contact with the image carrier, and the peripheral surface being separated from the image carrier by rotation;
A control unit for controlling the image to be carried on the image carrier passing through a position corresponding to the transfer nip when the transfer roller and the image carrier are separated by rotation of the transfer roller;
An image forming apparatus comprising: a detecting unit that detects the image. A latent image carrier for transferring an image to the image carrier;
An exposure unit that forms a latent image on the latent image carrier;
A developing section for developing the latent image formed on the latent image carrier,
The image forming apparatus according to claim 5, wherein the control unit controls a timing at which the exposure unit forms the latent image on the latent image carrier.   The image forming apparatus according to claim 5, further comprising a cleaning unit that cleans the image that has passed a position corresponding to the transfer nip.   The image forming apparatus according to claim 5, further comprising: a grip portion that grips the transfer material in the concave portion.

Images