JP2010145816A - Belt conveying device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of a belt, and also effectively remove a discharge product deposited on the belt. <P>SOLUTION: An intermediate transfer belt 32 is not heated, thereby prevents the deterioration of the belt. A cleaning roll 42 is brought into contact with the intermediate transfer belt 32 at an upper stream side of a drive roll 34 to thereby come into contact with a portion of the intermediate transfer belt 32 with high tension. Accordingly, the adhesion between the intermediate transfer belt 32 and the cleaning roll 42 is improved, even if a member opposing to the cleaning roll 42 across the intermediate transfer belt 32 is not present. Consequently, the discharge product deposited on the belt is effectively removed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a belt conveyance device and an image forming apparatus.

  As an image forming apparatus, an image forming apparatus disclosed in Patent Document 1 is known. The image forming apparatus disclosed in Patent Document 1 has a roll-like shape for cleaning the back surface of the intermediate transfer body 18 on the downstream side of the peeling roll 24 and the upstream side of the driving roll 19 on the moving path of the intermediate transfer body 18. A cleaning member 29 is disposed.

In the image forming apparatus disclosed in Patent Document 1, the heating roll 22 and the pressure roll 28 are heated and pressed by sandwiching the intermediate transfer body 18 and the recording body 23 between each other at the transfer fixing position T2. Then, the toner image conveyed to the transfer fixing position T2 is transferred and fixed onto the recording member 23.
Japanese Patent Laid-Open No. 11-231676 (FIG. 1)

  An object of the present invention is to suppress the deterioration of the belt body and to effectively remove the discharge products attached to the belt body.

  According to a first aspect of the present invention, there is provided a belt conveyance device in which an annular belt body that does not directly contact a heating source, the belt body is wound around, a driving roll that drives the belt body, and the belt body is wound around. The removal which contacts the inner peripheral surface of the said belt body between the winding roll, the said driving roll, and the upstream winding roll of this driving roll, and removes the discharge product adhering to this inner peripheral surface And a member.

  The belt conveyance device according to a second aspect of the present invention is the belt conveyance device according to the first aspect, wherein the belt body has a tension of 20 to 100N.

  The belt conveying apparatus according to a third aspect of the present invention is the belt conveying apparatus according to the first or second aspect, wherein the removing member is a porous elastic member having a number of cells of 100 (pieces / 25 mm) or less.

  According to a fourth aspect of the present invention, in the belt conveyance device according to the first or second aspect, the removing member is made of ECO rubber.

  The belt conveyance device according to a fifth aspect of the present invention is the belt conveyance device according to any one of the first to fourth aspects, wherein the removing member is disposed so as to be able to contact with and separate from the inner peripheral surface of the belt body. The belt contacts the inner circumferential surface of the belt while moving in the belt traveling direction.

  An image forming apparatus according to a sixth aspect of the present invention has an intermediate transfer belt as the belt body, and a housing in which the belt conveying device is accommodated. And a fixing device that is disposed outside the casing and heats and fixes the image transferred from the intermediate transfer belt to the recording medium.

  According to the configuration of the first aspect of the present invention, the deterioration of the belt body can be suppressed and the discharge products adhering to the belt body can be effectively removed as compared with the configuration in which the belt body is in a heated state.

  According to the configuration of the second aspect of the present invention, it is possible to ensure the adhesion between the removing member and the belt body and to suppress the elongation and breakage of the belt body as compared with the case where the present configuration is not provided.

  According to the structure of Claim 3 of this invention, compared with the structure using the porous elastic member in which the number of cells per 25 mm exceeds 100, a discharge product can be removed effectively.

  According to the configuration of claim 4 of the present invention, discharge products can be effectively removed as compared with a configuration using rubber other than ECO rubber.

  According to the structure of Claim 5 of this invention, compared with the structure where a removal member does not contact / separate, it can suppress that the discharge product which the removal member removed transfers to a belt body.

  According to the configuration of the sixth aspect of the present invention, the deterioration of the belt body is suppressed and the discharge product adhering to the belt body is suppressed as compared with the configuration in which the fixing device is in the casing in which the belt conveyance device is accommodated. Can be effectively removed.

Below, an example of an embodiment concerning the present invention is described based on a drawing.
(Configuration of image forming apparatus according to the present embodiment)
First, the configuration of the image forming apparatus according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present embodiment.

  The image forming apparatus 10 includes an apparatus main body 14 configured to include a housing 12 that houses each component. The apparatus main body 14 includes a plurality of image forming units 20, an intermediate transfer unit 30 as an example of a belt conveyance device, a recording medium storage unit 49 that stores a recording medium P such as paper, and a recording medium storage unit 49. A transport unit 50 that transports the recorded recording medium P is provided in the housing 12. A fixing device 80 is externally attached to the housing 12 of the apparatus main body 14.

  In the present embodiment, six image forming portions 20 are provided on the upper portion of the intermediate transfer belt 32 of the intermediate transfer unit 30, and are arranged along the straight portion of the intermediate transfer belt 32 on the outer peripheral side of the intermediate transfer belt 32. .

  Each of the six image forming units 20 includes four image forming units 20 that form toner images corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). Yes. The remaining two image forming units 20 include, for example, light color toners (light magenta, light cyan, etc.) for improving full color image quality (Gamut enlargement, graininess improvement), and red and green colors for widening the color gamut. Selected from an image forming unit that forms a toner image with a toner of gold or silver for special use, a black toner that is frequently used, or the like.

  The image forming unit 20 includes a photosensitive drum 22 that rotates in a predetermined direction (A direction in FIG. 1) as an example of an image holding body that holds an image.

  Around the photosensitive drum 22, a charging device 24 for charging the surface of the photosensitive drum 22 along the rotation direction of the photosensitive drum 22, and the surface of the charged photosensitive drum 22 is exposed to expose the photosensitive drum. An exposure device 26 that forms an electrostatic latent image on the surface, a developing device 28 that develops the electrostatic latent image formed on the surface of the photosensitive drum 22 to form a toner image, and a surface formed on the surface of the photosensitive drum 22 A first transfer roll 25 as an example of a first transfer unit for transferring the toner image to the intermediate transfer belt 32 and a toner removing device 29 for removing residual toner remaining on the photosensitive drum 22 are provided. ing.

  A voltage having a polarity opposite to the charge of the toner is applied to the first transfer roll 25, and the toner image on the photosensitive drum 22 is transferred onto the intermediate transfer belt 32. The first transfer unit may be, for example, a corona transfer device that is charged using corona discharge and transfers the toner image on the photosensitive member to the intermediate transfer belt 32 by the generated electric field.

  The intermediate transfer belt 32 of the intermediate transfer unit 30 conveys the toner image transferred by the first transfer roll 25 to the secondary transfer unit 60. The configuration of the intermediate transfer unit 30 will be described later.

  As shown in FIG. 1, the secondary transfer unit 60 transports the recording medium P downstream in the transport direction in the secondary transfer unit 60 and transfers the toner image transported to the intermediate transfer belt 32 to the recording medium P. A conveyance belt 56 is provided.

  The transfer conveyance belt 56 is formed in an annular shape, and is wound around a second transfer roll 62 to which a voltage having a polarity opposite to the toner charging polarity is applied, and a winding roll 64 arranged in parallel to the second transfer roll 62. It has been.

  The second transfer roll 62 is composed of a drive roll that is driven to rotate. When the second transfer roll 62 is driven to rotate, the transfer conveyance belt 56 circulates (rotates). The winding roll 64 is a driven roll that is driven by a transfer conveyance belt 56 that circulates and moves.

  Cleaning brushes 70 and 72 for cleaning the toner adhering to the transfer conveyance belt 56 are arranged in contact with the transfer conveyance belt 56. The cleaning unit that cleans the surface of the transfer conveyance belt 56 may be a blade member that contacts and cleans the surface of the transfer conveyance belt 56.

  The second transfer unit may be, for example, a corona transfer unit that is charged using corona discharge and transfers the toner image on the intermediate transfer belt 32 to the recording medium P by the generated electric field. Further, the second transfer unit may be constituted by the second transfer roll 62 alone, not the transfer conveyance belt 56.

  On the other hand, as shown in FIG. 1, the transport unit 50 performs a secondary transfer of the sending roll 52 that sends the recording medium P from the recording medium container 49 and the recording medium P that is sent from the recording medium container 49 by the sending roll 52. A plurality of transport rollers 54 transported to the unit 60, and a plurality of transport belts 58 that transport the recording medium P onto which the toner image has been transferred by the secondary transfer unit 60 to the fixing device 80.

  The fixing device 80 includes a housing 82 that is disposed outside the housing 12 of the apparatus main body 14 and is separate from the housing 12.

  The casing 82 is provided with a pressure roll 84 that pressurizes the recording medium P holding the toner, and a heating roll 86 that heats the recording medium P. The recording medium P is nipped and conveyed between the pressure roll 84 and the heating roll 86, whereby the toner on the recording medium P is melted and fixed. The fixing device 80 may be configured to be disposed in the housing 12 of the apparatus main body 14.

  In the image forming apparatus 10 described above, the six image forming units 20 are provided. However, the number is not limited to six, and may be four, for example. Further, the above-described configuration is a so-called tandem method, but a so-called four-cycle method may be used in which the development and transfer operations are repeated, and toner for four colors is transferred to a sheet after being overlaid.

(Configuration of intermediate transfer unit)
Next, as an example of a belt conveyance device that conveys a belt, a configuration of an intermediate transfer unit 30 that conveys an intermediate transfer belt will be described. FIG. 3 is a schematic diagram illustrating a configuration of the intermediate transfer unit 30 according to the present embodiment.

  The intermediate transfer unit 30 has an intermediate transfer belt 32 as an example of a belt body. The intermediate transfer belt 32 is in an unheated state. The non-heating state is a state in which a heating source such as a heating device (heating member) for heating is not in direct contact with the intermediate transfer belt 32, and a heating device for heating members other than the intermediate transfer belt 32 is the apparatus main body 14. Even in the case where it is disposed in the housing 12, it is in a state of being separated from the intermediate transfer belt 32.

  Therefore, the present embodiment may be configured such that the heating device that is separated from the intermediate transfer belt 32 is disposed in the housing 12 of the apparatus main body 14.

  The intermediate transfer belt 32 is configured, for example, by adding a conductive agent (carbon black, polyaniline, etc.) to a resin material (polyimide, polyamide, polyamideimide, etc.) or an elastic material (chloroprene, etc.).

  The intermediate transfer belt 32 is wound around a rotationally driven drive roll 34 and a plurality of winding rolls, and is configured to circulate and move when the drive roll 34 is rotationally driven. The plurality of winding rolls are configured to include a driven roll 36, a counter roll 38 that faces the second transfer roll 62, and a tension adjustment roll 40 that adjusts the tension of the intermediate transfer belt 32.

  The drive roll 34 and the plurality of winding rolls are rotatably supported by a support frame (not shown).

  The drive roll 34 is arranged on one side in the horizontal direction, which is the arrangement direction in which the image forming unit 20 and the first transfer roll 25 are arranged, specifically, on the rightmost side in FIG.

  The tension adjusting roll 40 is disposed on the other side in the horizontal direction, which is the arrangement direction in which the image forming unit 20 and the first transfer roll 25 are arranged, specifically, on the leftmost side in FIG.

  The opposing roll 38 is arranged on the opposite side (see FIG. 1) from the side where the image forming unit 20 (photosensitive drum 22) is arranged as viewed from the intermediate transfer belt 32, specifically, on the lowermost side in FIG. Has been.

  The intermediate transfer belt 32 is turned from right to left in FIG. 3 at the portion of the drive roll 34, and the moving direction is changed from right to left. Further, the intermediate transfer belt 32 protrudes to the right side in FIG.

  The intermediate transfer belt 32 is folded back from left to right in FIG. 3 at the tension adjusting roll 40, and the moving direction is changed from left to right. Further, the intermediate transfer belt 32 protrudes to the left side in FIG.

  The intermediate transfer belt 32 is folded from the bottom to the top in FIG. 3 at the portion of the opposing roll 38, and the moving direction is changed from the bottom to the top. Further, the intermediate transfer belt 32 protrudes downward in FIG.

  The tension adjusting roll 40 is provided with a pressing member such as a spring that presses the tension adjusting roll 40 against the intermediate transfer belt 32. By changing the pressing force of the pressing member, the tension of the intermediate transfer belt 32 is increased. Adjusted.

  The tension of the intermediate transfer belt 32 is adjusted by the tension adjusting roll 40 so that the tension is 20 to 100N. As a method for measuring the tension of the intermediate transfer belt 32 (a method for calculating the tension of the intermediate transfer belt 32), for example, the spring load that presses the tension adjusting roll 40 is measured with only the spring, and the total value Ften, the spring center line, The belt surface angles θ1 and θ2 are respectively substituted into Equation 1, and the belt tension Fbelt is calculated (see FIGS. 2A and 2B).

Ften ＝ Ften1 + Ften2
Fbelt ・ cosθ1 + Fbelt ・ cosθ2 ＝ Ften
∴Fbelt = Ften / (cosθ1 + cosθ2) ・ ・ ・ Equation 1
If the tension of the intermediate transfer belt 32 is less than 20 N, the adhesion between the cleaning roll and the intermediate transfer belt 32 cannot be ensured. Further, if the tension of the intermediate transfer belt 32 is less than 20N, slip is likely to occur between the intermediate transfer belt 32 and the drive roll 34 and the belt transfer stability of the intermediate transfer belt 32 cannot be ensured.

  On the other hand, when the tension of the intermediate transfer belt 32 exceeds 100 N, the extension of the intermediate transfer belt 32 or the breakage of the intermediate transfer belt 32 may occur. When the tension of the intermediate transfer belt 32 exceeds 100 N, it is necessary to increase the rigidity of the support frame that supports the drive roll 34 and the plurality of winding rolls, which increases the weight and size of the support frame. .

  Further, as shown in FIG. 4, the intermediate transfer unit 30 includes a cleaning blade 46 that cleans the outer peripheral surface of the intermediate transfer belt 32. The cleaning blade 46 is supported by the support portion 45, and the tip of the cleaning blade 46 contacts the outer peripheral surface of the intermediate transfer belt 32 that is downstream of the opposing roll 38 and upstream of the drive roll 34. It is supposed to be.

  On the inner peripheral side of the intermediate transfer belt 32, a counter roll 48 is provided as an example of a counter member disposed to face the cleaning blade 46 with the intermediate transfer belt 32 interposed therebetween. The counter roll 48 has an outer peripheral surface in contact with an inner peripheral surface of the intermediate transfer belt 32.

  As a result, the outer peripheral surface of the intermediate transfer belt 32 that circulates and the tip of the cleaning blade 46 come into contact with each other, and scrapes such as paper dust, residual toner, and external additives attached to the outer peripheral surface of the intermediate transfer belt 32 are scraped. take. The cleaning blade 46 is made of rubber, metal or the like.

  Here, the intermediate transfer unit 30 is in contact with the inner peripheral surface of the intermediate transfer belt 32 on the upstream side of the drive roll 34, and is a cleaning roll as an example of a removing member that removes discharge products attached to the inner peripheral surface. 42 is provided.

  The cleaning roll 42 is disposed at a predetermined distance on the upstream side of the drive roll 34, and comes into contact with a portion of the intermediate transfer belt 32 on the upstream side of the drive roll 34. The portion of the intermediate transfer belt 32 on the upstream side of the drive roll 34 is a region that is half the circumference of the intermediate transfer belt 32 on the upstream side in the movement direction of the intermediate transfer belt 32 when viewed from the drive roll 34. The portion of the intermediate transfer belt 32 on the downstream side of the drive roll 34 is a region that is half the circumference of the intermediate transfer belt 32 on the downstream side in the movement direction of the intermediate transfer belt 32 when viewed from the drive roll 34.

  The cleaning roll 42 is disposed between the winding roll disposed on the most upstream side of the drive roll 34 and the drive roll 34 on the moving path of the intermediate transfer belt 32. The cleaning roll 42 contacts a linear portion 32A of the intermediate transfer belt 32 that is formed in a substantially linear shape in a side view between the driving roll 34 and the winding roll. The cleaning roll 42 is more preferably in contact with the drive roll 34 from the center of the linear portion 32A of the intermediate transfer belt 32.

  Note that the winding roll in the present embodiment corresponds to the facing roll 38 disposed to face the second transfer roll 62 instead of the facing roll 48 disposed to face the cleaning blade 46.

  The counter roll 48 is composed of a metal roll and the contact amount of the intermediate transfer belt 32 is small, whereas the counter roll 38 is composed of an elastic body such as rubber and the intermediate transfer belt 32. There is a large amount of contact (wound amount).

  The cleaning roll 42 does not need to be arranged on the most upstream side of the drive roll 34, and even if the roll is arranged between the cleaning roll 42 and the drive roll 34 as in the present embodiment, Good.

  The distance between the cleaning roll 42 and the drive roll 34 is specifically 210 mm as the distance between the centers of the rolls. In addition, the outer diameter of the cleaning roll 42, the outer diameter of the drive roll 34, and the outer diameter of the opposing roll 48 may be the same, for example, 28 mm. The width of the intermediate transfer belt 32 may be 359 mm, for example, and the thickness may be 0.1 mm, for example.

  Further, the cleaning roll 42 is configured to be driven to rotate following the intermediate transfer belt 32 at a speed slower than the surface speed of the intermediate transfer belt 32. That is, the cleaning roll 42 rotates counterclockwise in the same manner as the intermediate transfer belt 32 circulates counterclockwise in FIG.

  The cleaning roll 42 may be configured to rotate following the intermediate transfer belt 32 while slipping with the intermediate transfer belt 32. Further, the cleaning roll 42 may be fixed and not rotated, or may be configured to rotate in a direction opposite to the direction in which the intermediate transfer belt 32 circulates.

  As the cleaning roll 42, for example, a porous elastic member, metal (aluminum, stainless steel, copper, iron, etc.), resin, and elastic body are used.

  Specifically, as the cleaning roll 42, for example, ether-based urethane foam, polyethylene foam, polyolefin foam, melamine foam, micropolymer, or the like is used. Moreover, you may use another insulating material as a cleaning roll.

  The production method will be briefly explained. In the case of polyurethane foam, it is produced using polyol, isocyanate, water, catalyst (amine catalyst, metal catalyst, etc.) and foam stabilizer (surfactant). Additives such as pigments are used. When these raw materials are mixed and stirred, a chemical reaction occurs, and a urethane resin foam is completed.

  As the porous elastic member, for example, urethane foam or the like is used. An ether type is used as the urethane foam. The porous elastic member preferably has a cell count of 100 (pieces / 25 mm) or less.

  When the number of cells exceeds 100 (cells / 25 mm), the removed discharge product is hardly held in the porous elastic member, the discharge product is deposited on the surface, and the discharge product is reattached to the intermediate transfer belt 32. There is a fear.

  Desirably, further sufficient performance is ensured by setting the number of cells to 40 to 80 (cells / 25 mm). When the number of cells is too small, the effect of storing discharge products in the cell portion of the elastic body is reduced.

  Moreover, as an elastic body which is a material of the cleaning roll 42, for example, a rubber material such as epichlorohydrin rubber (ECO rubber) ethylene-propylene-diene rubber (EPDM rubber) is used.

  In addition, the cleaning roll 42 is disposed so as to be able to contact and separate from the inner peripheral surface of the intermediate transfer belt 32. Specifically, the rotation shaft 42 </ b> A of the cleaning roll 42 is rotatably supported by the support member 44, and the support member 44 has a contact position where the cleaning roll 42 contacts the inner peripheral surface of the intermediate transfer belt 32, and cleaning. The roll 42 is configured to oscillate between a separation position separated from the inner peripheral surface of the intermediate transfer belt 32.

  The cleaning roll 42 is, for example, in the image forming operation, that is, when the transfer by the first transfer roll 25 and the transfer by the secondary transfer unit 60 are performed, and the intermediate transfer belt 32 is circulated and moved. When the intermediate transfer belt 32 is in contact with the intermediate transfer belt 32 and is stopped, the intermediate transfer belt 32 is separated.

  When the swing shaft 44A of the support member 44 and the rotation shaft 42A of the cleaning roll 42 are viewed from the intermediate transfer belt 32 side in the surface direction (the direction of arrow B in FIG. 4), the swing shaft 44A is the rotation shaft 42A. Further, the intermediate transfer belt 32 is disposed on the downstream side in the traveling direction (in the direction of arrow C in FIG. 4).

  When the swing shaft 44A of the support member 44 and the rotation shaft 42A of the cleaning roll 42 are viewed from the upstream in the travel direction of the intermediate transfer belt 32 to the downstream in the travel direction (the direction of arrow D in FIG. 4), the swing shaft 44A. Is disposed on the opposite side of the rotation shaft 42A from the intermediate transfer belt 32 (in the direction of arrow E in FIG. 4).

  As a result, the cleaning roll 42 contacts the inner peripheral surface of the intermediate transfer belt 32 while drawing an arc orbit and moving in the belt traveling direction.

  For this reason, when the intermediate transfer belt 32 travels, the cleaning roll 42 receives a force in the direction of biting into the intermediate transfer belt 32, so that the adhesion between the cleaning roll 42 and the intermediate transfer belt 32 increases.

  In addition, the cleaning roll 42 can be brought into close contact with the intermediate transfer belt 32 even when the force for pressing the cleaning roll 42 against the intermediate transfer belt 32 is weakened, compared to the configuration in which the cleaning roll 42 is in contact with and separated from the intermediate transfer belt 32 in the vertical direction. .

  The cleaning roll 42 may be configured to be in contact with the inner peripheral surface of the intermediate transfer belt 32 while moving in the belt traveling direction while drawing a linear track. In other words, the cleaning roll 42 may be in contact with or separated from the intermediate transfer belt 32 along the oblique direction F with respect to the intermediate transfer belt 32.

  The housing 12 may be configured to come into contact with the intermediate transfer belt 32 only under a high temperature and high humidity condition in which the inside of the housing 12 reaches a predetermined temperature and humidity.

  Moreover, as a structure which contacts / separates the cleaning roll 42, it is not restricted to said structure, For example, the structure which contacts / separates the cleaning roll 42 with drive devices, such as a linear actuator, may be sufficient, and various structures can be considered.

  Further, the cleaning roll 42 is not limited to a roll shape. Further, the removing member is not limited to the cleaning roll 42 but may be a blade or a brush.

  In the present embodiment, an example in which the intermediate transfer belt 32 is used as the belt body has been described. However, the belt body may be a conveyance belt or a photosensitive belt.

(Operation of the image forming apparatus according to the present embodiment)
Next, the operation of the image forming apparatus according to this embodiment will be described.

  In the present embodiment, the toner image on the photosensitive drum 22 is transferred onto the intermediate transfer belt 32 by applying a voltage having a polarity opposite to the toner charge to the first transfer roll 25.

  The toner image transferred onto the intermediate transfer belt 32 is transferred to the recording medium P by applying a voltage having a polarity opposite to the charged polarity of the toner to the second transfer roll 62 of the secondary transfer unit 60.

  The discharge generated in the first transfer roll 25 and the secondary transfer unit 60 to which a voltage is applied generates discharge products such as ozone and nitrogen oxide, and the discharge products adhere to the inner peripheral surface of the intermediate transfer belt 32. .

  The intermediate transfer belt 32 is in an unheated state, and the intermediate transfer belt 32 tends to be in a high humidity environment. If the discharge product adhering to the inner peripheral surface of the intermediate transfer belt 32 absorbs moisture in a high humidity environment, the electrical resistance of the intermediate transfer belt 32 is reduced and the charge retention is reduced, resulting in a transfer failure.

  On the other hand, in this embodiment, since the discharge product adhering to the inner peripheral surface of the intermediate transfer belt 32 is removed, transfer defects are reduced.

  In this embodiment, since the intermediate transfer belt 32 receives a driving force from the drive roll 34, the intermediate transfer belt 32 is pulled on the upstream side of the drive roll 34 to increase the tension, and the intermediate transfer belt 32 on the downstream side of the drive roll 34. The belt 32 is loosened and the tension is lowered.

  Since the cleaning roll 42 is in contact with the intermediate transfer belt 32 on the upstream side of the drive roll 34, the cleaning roll 42 is in contact with a portion of the intermediate transfer belt 32 having high tension, and faces the cleaning roll 42 with the intermediate transfer belt 32 interposed therebetween. Even when there is no opposing member, the adhesion between the intermediate transfer belt 32 and the cleaning roll 42 is improved.

In the present embodiment, the cleaning roll 42 is a case where the transfer by the first transfer roll 25 and the transfer by the secondary transfer unit 60 are performed, and the intermediate transfer belt 32 moves in a circulating manner. When the intermediate transfer belt 32 is in contact with the belt 32 and stopped, the belt is separated from the intermediate transfer belt 32.
Accordingly, when the intermediate transfer belt 32 is stopped, the discharge product removed by the cleaning roll 42 is not easily transferred to the intermediate transfer belt 32.

(Evaluation of Examples and Comparative Examples)
Next, evaluation in the following examples and comparative examples will be described.
FIG. 5 is a table showing evaluation results of examples and comparative examples in which a roll of a firing system is used as the cleaning roll according to the present embodiment. FIG. 6 is a table showing evaluation results of examples and comparative examples in which a rubber roll is used as the cleaning roll according to the present embodiment.

  Evaluation is performed in a high-temperature, high-humidity (28 degrees 85% RH) environment, running 100,000 A4 size sheets, and after standing for 24 hours, measure the density difference of Cin20% halftone images (difference between normal and white areas). I went.

  Cin represents the fineness of an image and refers to an image density coverage (Input Coverage) representing an image area ratio per dot of input image data.

  A sample prepared immediately after starting the apparatus after being left for 24 hours is evaluated as (A), (A) and (B) a sample prepared after idling of an intermediate transfer belt equivalent to 200 sheets of A4 size. It was.

  In the evaluation, in the image forming apparatus 10 described above, the rolls according to the following examples and comparative examples were used as the cleaning roll 42, and the conditions of the other apparatus configurations were the same. At this time, the cleaning roll 42 was always in contact with the fixing device 80 and the intermediate transfer unit 30 and the experiment was performed with a separate casing.

(Example in which a roll of a firing system is used as the cleaning roll 42)
Example 1
Product name "EP70" (manufactured by Inoac Corporation)
Cell density (pieces / 25 mm) 65 pieces (Example 2)
Product name "RR26" (manufactured by Inoac Corporation)
Cell density (pieces / 25 mm) 40 pieces (Example 3)
Product name "RR80" (manufactured by Inoac Corporation)
Cell density (pieces / 25 mm) 40 pieces (Example 4)
Product name "RMM" (manufactured by Inoac Corporation)
Cell density (pieces / 25 mm) 50 pieces (Example 5)
Product name “SP80” (manufactured by Inoac Corporation)
Cell density (pieces / 25mm) 80 pieces (Comparative Example 1)
No cleaning roll (Comparative Example 2)
Product name "PORON" (manufactured by Inoac Corporation)
Cell density (pieces / 25mm) 125 pieces (Comparative Example 3)
Product name "MAPS" (manufactured by Inoac Corporation)
Cell density (pieces / 25 mm) 500 pieces (an example in which a rubber roll is used as the cleaning roll 42)
Example 1
ECO rubber (epichlorohydrin rubber)
(Example 2)
EPDM rubber (ethylene-propylene-diene rubber)
(Comparative Example 1)
CR rubber (chloroprene rubber)
As a result of evaluating the above examples and comparative examples, as shown in FIGS. 5 and 6, it was confirmed that the decrease in density was reduced and the blanking level was below the allowable range for the examples.
The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present embodiment. FIG. 2 is a conceptual diagram for explaining a tension measuring method (calculation method) of the tension adjusting roll according to the present embodiment. FIG. 3 is a schematic diagram showing the intermediate transfer unit according to the present embodiment. FIG. 4 is a schematic diagram illustrating a peripheral configuration of the cleaning roll according to the present embodiment. FIG. 5 is a table showing evaluation results of examples and comparative examples in which a roll of a firing system is used as the cleaning roll according to the present embodiment. FIG. 6 is a table showing evaluation results of examples and comparative examples in which a rubber roll is used as the cleaning roll according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Case 30 Intermediate transfer unit (belt conveyance apparatus)
32 Intermediate transfer belt (belt body)
34 Drive roll 36 Driven roll (winding roll)
38 Opposite roll (roll roll)
40 Tension adjustment roll (winding roll)
42 Cleaning roll (removal member)
80 Fixing device

Claims (6)

An annular belt body not in direct contact with the heating source;
A drive roll around which the belt body is wound to drive the belt body;
A winding roll around which the belt body is wound;
A removal member that contacts the inner peripheral surface of the belt body between the drive roll and a winding roll on the upstream side of the drive roll, and removes discharge products attached to the inner peripheral surface;
A belt conveyance device comprising:   The belt conveyance device according to claim 1, wherein the belt body has a tension of 20 to 100N.   3. The belt conveying device according to claim 1, wherein the removing member is formed of a porous elastic member having a number of cells of 100 (pieces / 25 mm) or less.   The belt conveying device according to claim 1, wherein the removing member is made of ECO rubber.   The said removal member is arrange | positioned so that contact / separation is possible with respect to the internal peripheral surface of the said belt body, and contacts the said belt internal peripheral surface, moving in the advancing direction of the said belt. The belt conveying apparatus as described. The belt conveyance device according to any one of claims 1 to 5, having an intermediate transfer belt as the belt body,
A housing that houses the belt conveying device;
A fixing device that is disposed outside the casing and heats and fixes the image transferred from the intermediate transfer belt to the recording medium;
An image forming apparatus.

Images