JP2015118217A - Conveyance apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance apparatus configured to prevent abrasion powder from being generated due to contact between a belt and a contact surface of a fixing member, while preventing the conveyance apparatus from being contaminated with the abrasion powder.SOLUTION: A conveyance apparatus includes: a circulating annular belt; a tension applying roll which presses the belt toward an outer periphery to apply tension to the belt; a fixing member which is fixed on an inner periphery side of the belt and has a contact surface to be brought into contact with an inner peripheral surface of the belt; and a pressing member which is arranged on an outer periphery side of the belt to press the belt against the contact surface of the fixing member and to press a sheet-like conveyance material against a part of the outer peripheral surface of the belt passing through the contact surface of the fixing member. In an entrance area, where belt contact begins, in the contact surface of the fixing member and an exit area where the belt finishes passing through, a sheet material is fixed which shows a smaller dynamic friction coefficient than that for the inner peripheral surface of the belt in the contact surface of the fixing member.

Description

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

As a conveying device of a type in which a fixing member having a contact surface that contacts an inner peripheral surface of a circular belt that circulates is arranged, and a sheet-like material to be conveyed is pressed against the outer peripheral surface of the belt, for example, The following are known:
In other words, the annular first belt that circulates and the outer periphery of the first belt are arranged, and the material to be conveyed is circulated and sandwiched between the first belt, and the material to be conveyed is moved to the first belt. And the first belt is wound around, and the first belt is pushed toward the outer peripheral side to apply tension to the first belt. A first roll that moves the first belt in a belt width direction orthogonal to the moving direction, and the second belt is wound around, and the second belt is pushed toward the outer periphery to apply tension to the second belt, A second roll for moving the second belt in a belt width direction orthogonal to the moving direction of the second belt by tilting, and an inner peripheral side of at least one of the first belt and the second belt, The first belt and A pressing member for pressing one of the serial second belt to the other, a conveying device provided with a (patent document 1).

In addition, as an apparatus of the above type, in an electrophotographic apparatus having a means for forming a toner image based on recorded information on a heat-resistant belt and a heating means for transferring and fixing the toner image on the heat-resistant belt to a sheet, The cooling means for cooling the heat-resistant belt is disposed in contact with the inner surface of the heat-resistant belt, and the cooling means has a cooling fan and is in contact with the inner surface of the heat-resistant belt. There is known an apparatus configured to have a cooling means subjected to a process for reducing a contact friction coefficient on the side to be performed (Patent Document 2).
In Patent Document 2, as a process for reducing the coefficient of contact friction, a polyimide film is provided on the contact surface of the cooling means with the heat-resistant belt, or a fluororesin is further coated thereon. In addition, it is shown that the contact surface is directly coated with a fluororesin.

Furthermore, as an apparatus of the above-mentioned type, it has an endless fixing film that is driven to travel, a heating body and a pressure member that are pressed against each other, and pressurization between the heating body and the pressure member with the fixing film interposed therebetween. The recording material carrying an unfixed image is introduced between the fixing film and the pressure member of the fixing nip portion formed by moving the fixing nip portion together with the traveling fixing film to move from the heating body to the recording material. A fixing device that thermally fixes an image by applying thermal energy has a fixed guide member that holds the heating body, and a long flow path is provided in the fixed guide member in the longitudinal direction so that the fixed guide member and the fixing film slide. There is known an apparatus having an air pump for providing a blowing hole communicating with the flow path on a friction surface and blowing air from the friction surface of a fixed guide member by flowing air through the flow path (Patent Document 3).
According to Patent Document 3, according to this apparatus, the generation of wear powder that the inner peripheral surface of the fixing film is worn by sliding with the heating body (heater support) is reduced as much as possible, and the wear powder rotates the fixing film. It has been shown that the film can operate reliably without sticking to the surface of the driving roller to be slipped on the driving roller.

JP 2011-121711 A JP 05-27603 A Japanese Patent Laid-Open No. 06-83219

  This invention suppresses generation | occurrence | production of abrasion powder by a belt contacting with the contact surface of a fixing member as a conveyance apparatus of the said form, and reducing that conveyance apparatus becomes dirty with the abrasion powder. It is an object of the present invention to provide an image forming apparatus using the transport device.

  The conveying device of the present invention (A1) includes an annular belt that circulates, a tension applying roll that applies the tension to the belt by pushing the belt to the outer peripheral side, and an inner belt. A fixing member arranged fixedly on the circumferential side and having a contact surface contacting the inner circumferential surface of the belt; and arranged on the outer circumferential side of the belt, pressing the belt against the contact surface of the fixing member and A pressing member that presses the sheet-like material to be conveyed to a portion of the outer peripheral surface that passes through the contact surface of the fixing member, and an entrance region where the belt starts to contact among the contact surfaces of the fixing member or the A sheet material having a dynamic friction coefficient smaller than the dynamic friction coefficient with respect to the inner peripheral surface of the belt at the contact surface of the fixing member is fixed to the exit region where the belt has passed. And it is characterized in and.

  The conveying device according to the present invention (A2) conveys a material to be conveyed conveyed from a fixing device that thermally fixes an image formed on the sheet-shaped material to be conveyed in the conveying device according to the invention A1.

  The conveying device of the invention (A3) is the conveying device of the invention A1 or A2, wherein the fixing member is a heat radiating member.

  The conveying device according to the present invention (A4) is the conveying device according to any one of the above inventions A1 to A3, wherein the pressing member is disposed in contact with the outer peripheral surface of the belt, and a sheet-like covering is provided between the belt and the belt. It has an annular second belt that circulates so as to be conveyed with the conveying material sandwiched therebetween.

  The conveying device according to the present invention (A5) is the conveying device according to any one of the above inventions A1 to A4, wherein the entrance region of the contact surface of the fixing member is the maximum from the contact start position with the belt, and the belt on the contact surface. The area extending to the downstream side in the moving direction of the belt by a dimension of 1/3 of the length in the moving direction of the fixing member, and the exit area of the contact surface of the fixing member is the maximum from the contact end position with the belt Thus, the contact surface is a region up to a position where it enters the upstream side of the belt in the moving direction by a distance of 1/3 of the length in the moving direction of the belt.

  The image forming apparatus according to the present invention (B1) is the conveying apparatus according to any one of the inventions A1 to A5 as a conveying apparatus that conveys at least one sheet-like recording medium before and after the image is formed. It is characterized by having.

  According to the conveying device of the invention A1, the belt is fixed to the contact surface of the fixing member as compared with the case where the sheet material is not fixed to the contact surface of the fixing member or the region other than the specific region of the contact surface is fixed. It is possible to suppress the generation of wear powder due to contact and wear, and to reduce the contamination of the conveying device by the wear powder.

  In the transport device of the invention A2, the effect of the invention A1 can be obtained as compared to the case where the configuration of the invention is not provided.

  In the transport device of the invention A3, the effect of the invention A1 or A2 can be achieved without reducing the function of the heat radiating member of the fixing member to absorb and dissipate the heat of the transported material through the belt by contact with the belt. Can be obtained.

  In the conveying device of the invention A4, compared to the case where the pressing member does not have the second belt, the material to be conveyed is favorably applied to the portion of the belt that contacts the contact surface of the fixing member by the pressing member. The effect of any of the inventions A1 to A3 can be obtained while being conveyed in contact.

  In the conveying device of the invention A5, the invention can be applied to the inventions of the inventions A1 to A4 without impairing the function exerted by the contact of the fixing member with the belt as compared to the case where the structure of the entrance region or the exit region for fixing the sheet material is not provided. The effect by either can be acquired.

  According to the image forming apparatus of the invention B1, the generation of abrasion powder due to the belt contacting the contact surface of the fixing member and wearing in the conveyance apparatus is suppressed, and the conveyance apparatus is contaminated by the abrasion powder. The recording medium can be transported satisfactorily by the transport device.

1 is a schematic diagram illustrating a configuration of an image forming apparatus (including a transport device) according to Embodiment 1. FIG. FIG. 2 is an enlarged schematic diagram illustrating a configuration of an image forming apparatus in the image forming apparatus of FIG. 1. 1 is a schematic diagram illustrating a configuration of a transport device according to Embodiment 1. FIG. It is explanatory drawing for demonstrating correction | amendment of the meandering (one side deviation) of the upper belt in the conveying apparatus of FIG. It is explanatory drawing for demonstrating correction | amendment of meandering (deviation) of the lower belt in the conveying apparatus of FIG. It is the schematic which expands and shows the state of the sheet | seat material fixed to the contact surface of the heat radiating member in a conveying apparatus, and the structure of the periphery part. It is the schematic which expands and shows the structure of the contact surface of the heat radiating member of FIG. 6, and a sheet | seat material. It is a graph which shows the test result about the static friction coefficient of each meandering correction | amendment roll before a use stage and after a test. It is explanatory drawing for demonstrating the state (test condition) which each fixed the sheet | seat for a test to each test area of the contact surface of a thermal radiation member in a test. FIG. 10 is a chart showing results when a soiling confirmation test is performed under the test conditions of FIG. 9. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (simply referred to as “embodiments”) will be described with reference to the accompanying drawings.

[Embodiment 1]
FIG. 1 shows a configuration of an image forming apparatus using the transport device according to the first embodiment. The arrows indicated by reference signs X, Y, and Z in the drawings are orthogonal coordinate axes (directions) indicating the respective directions of the width, height, and depth of the three-dimensional space assumed in each drawing.

<Configuration of image forming apparatus>
The image forming apparatus 1 according to the first embodiment is an apparatus that forms a color image or a monochrome image composed of characters, figures, patterns, photographs, and the like. The image forming apparatus 1 includes a first casing 80A constituting a part on one side in the horizontal direction (a direction along the arrow X of the coordinate axis in FIG. 1) and a first casing 80A that is detachably connected to the horizontal direction. And a second housing 80B that constitutes the other side portion. The first housing 80A and the second housing 80B are composed of various members such as a required support frame and an exterior cover.

  First, in the first housing 80A, yellow (Y), magenta (M), cyan (C), and black (K) toner images and two types of special toner images S1 and S2 are respectively displayed. Six image forming apparatuses 10Y, 10M, 10C, 10K, 10S1, and 10S2 that are formed exclusively and the toner images formed by the respective image forming apparatuses 10 are respectively held by transfer (primary transfer), and finally sheet-shaped. An intermediate transfer device 20 that transports to a secondary transfer position for transfer (secondary transfer) to a recording paper 9 that is an example of a recording medium, and a required recording paper 9 to be supplied to the secondary transfer position of the intermediate transfer device 20 are accommodated. The paper supply device 30 and the like to be sent out are arranged. A one-dot chain line in FIG. 1 indicates a main conveyance path of the recording paper 9.

  The six image forming devices 10 (S1, S2, Y, M, C, and K) are arranged in a line along the substantially horizontal direction in the internal space of the first housing 80A. As the developer (S1, S2) of the special color (S1, S2), for example, a developer composed of a coloring material that is difficult or impossible to express with the above four colors is used. Toners of colors other than the above four colors, toners that are the same color as the above four color toners and differ in saturation, transparent toners that improve gloss, foamable toners for Braille, fluorescent color toners, and the like. In addition, the image forming apparatuses 10 (S1, S2, Y, M, C, and K) have substantially the same configuration as described below except that the types of developers to be handled are different.

  Each image forming apparatus 10 (S1, S2, Y, M, C, and K) includes a rotating photosensitive drum 11 as shown in FIG. 1 and FIG. A charging device 12 that charges a peripheral surface (image holding surface) capable of forming an image of the drum 11 to a required potential, and exposure light LB (dotted line) based on image information (signal) on the charged peripheral surface of the photosensitive drum 11. ) To form an electrostatic latent image (for each color) having a required potential, and the electrostatic latent image corresponding to each corresponding color (S1, S2, Y, M, C, K). A developing device 14 (S1, S2, Y, M, C, K) that develops each of the toners 4 with toner of the developer 4 and a primary transfer device 15 that transfers the toner images to the intermediate transfer device 20. Adhered matter such as toner remaining on the image holding surface of the photosensitive drum 11 after the primary transfer Drum cleaning device 16 for removing and cleaning discharger 17 such that neutralizes the image holding surface after cleaning of the photosensitive drum 11 are arranged in this order.

  The photosensitive drum 11 is formed by forming an image holding surface having a photoconductive layer (photosensitive layer) made of a photosensitive material on the peripheral surface of a cylindrical conductive substrate to be grounded. It receives power and rotates in the direction indicated by the arrow. The charging device 12 is, for example, a non-contact type charging device (Scotron type) that applies a charging bias to a discharge wire arranged in a state where a predetermined interval is provided on the image holding surface of the photosensitive drum 11 and charges it by corona discharge. Corona discharger). As the charging bias, when the developing device 14 performs reverse development, a voltage or current having the same polarity as the charging polarity of the toner supplied from the developing device is supplied from a power supply device (not shown).

  The exposure device 13 (S1, S2, Y, M, C, K) charges the photosensitive drum 11 with exposure light LB configured according to image information input to the image forming apparatus 1 from an external device (not shown) or the like. Irradiates a subsequent image holding surface to form an electrostatic latent image. For example, a scanning exposure apparatus configured using optical components such as a semiconductor laser and a polygon mirror, a light emitting diode and an optical component, etc. This is a non-scanning type exposure apparatus constituted by using the above. The developing device 14 (S1, S2, Y, M, C, K) uses, for example, a two-component developer including toner and carrier. As shown in FIG. 2, the developing device 14 (S1, S2, Y, M, C, K) includes a container-like housing 14a that houses a two-component developer of any one of the colors, The developing roller 14 b and the like are configured to hold and supply the developer 4 contained therein to a developing area facing the photosensitive drum 11. In the developing device 14 (S1, S2, Y, M, C, K), a developer container 19 (S1, S2, Y, M, C, K) is detachably mounted on the upper portion of the first casing 80A. Thus, toner of a required color is supplied through a supply device (not shown).

  The primary transfer device 15 is, for example, a contact-type transfer device including a primary transfer roll that rotates in contact with the peripheral surface of the photosensitive drum 11 and is supplied with a primary transfer voltage. As the primary transfer voltage, a DC voltage having a polarity opposite to the charging polarity of the toner is supplied from a power supply device (not shown). The drum cleaning device 16 includes a container-like housing 16a and a cleaning plate 16b that is disposed so as to be in contact with the outer peripheral surface of the photosensitive drum 11 with a required pressure and scrapes off adhering matter such as toner that remains and adheres. It is configured.

  As shown in FIG. 1, the intermediate transfer device 20 is disposed so as to exist at a position below each image forming device 10 (S1, S2, Y, M, C, K). The intermediate transfer device 20 includes an annular intermediate transfer belt 21 that rotates (circulates) in a direction indicated by an arrow while passing through a portion that is a primary transfer position (a portion facing the primary transfer device 15) on the photosensitive drum 11. A plurality of support rolls 22a to 22d that hold the intermediate transfer belt 21 in a desired state from the inner surface and rotatably support the intermediate transfer belt 21, and an outer surface (image holding surface) of the intermediate transfer belt 21 supported by the support roll 22e. The secondary transfer device 25 that rotates in contact with a predetermined pressure, and the toner, paper dust, and other adhering matter remaining on the outer surface of the intermediate transfer belt 21 after passing through the secondary transfer device 25 are removed and cleaned. It is comprised by the belt cleaning apparatus etc. which are not shown in figure.

  Among the plurality of support rolls 22a to 22f, the support roll 22a is configured as a drive roll, the support roll 22c is configured as a tension applying roll, and the support roll 22e is configured as a secondary transfer auxiliary roll. The secondary transfer device 25 is, for example, a contact-type transfer device including a secondary transfer roll that rotates in contact with the outer surface of the intermediate transfer belt 21 and is supplied with a secondary transfer bias. As the secondary transfer bias, a DC voltage or the like having a polarity opposite to the charging polarity of the developer is supplied from a power supply device (not shown).

  Two paper supply devices 30 are arranged so as to exist at a position below the intermediate transfer device 20. This paper supply device 30 is mainly composed of a paper storage body 31 for storing recording paper 9 of a desired size and type in a stacked state, and a delivery device 32 for sending the recording paper 9 from the paper storage body 31 one by one. It is configured. The paper container 31 is attached so that it can be pulled out from the inside of the first housing 80A to the outside, and the recording paper 9 is stored (supplemented) in the pulled-out state.

  In addition, a supply conveyance path is provided between the paper supply device 30 and the secondary transfer position of the intermediate transfer device 20 (the portion where the intermediate transfer belt 21 and the secondary transfer device 25 are in contact) between the first casing 80A. 50 is provided. Further, a transfer device 53 for transferring the recording paper 9 after the secondary transfer to the fixing device 40 is disposed between the secondary transfer device 25 and a fixing device 40 described later. The supply conveyance path 50 is composed of a plurality of conveyance roll pairs and conveyance guide materials. The transfer device 53 wraps and rotates an annular transfer belt around a plurality of rolls, and transfers the recording paper 9 after the secondary transfer onto the outer peripheral surface portion located above the transfer belt in a state of being sucked and placed. These belt transfer devices are arranged in series.

  Next, in the second casing 80B, as shown in FIG. 1, a fixing device 40 for overheating and fixing the toner image on the recording paper 9 secondarily transferred by the intermediate transfer device 20, and a fixing device 40 A conveyance device (cooling device) 100 that conveys the recording paper 9 after fixing and cools the recording paper 9 during conveyance, and the recording paper 9 after image formation carried out of the conveyance device 100 is provided outside the housing 80B. A discharge accommodating portion 60 and the like are accommodated.

  The fixing device 40 includes an annular fixing belt 41 that circulates and a pressure roll 42 that is disposed so as to rotate in contact with the fixing belt 41 from below. The fixing belt 41 is wound around the driving roll 43, the driven roll 44, and the other roll 45 in a tensioned state, and rotates in a certain direction. The drive roll 43 is disposed so as to face the pressure roll 42 from above, and the driven roll 44 is disposed above the drive roll 43. The driving roll 43 and the driven roll 44 have a structure in which heating means such as a halogen heater is disposed in the internal space thereof, whereby the fixing belt 41 is heated to a required temperature. The details of the transfer device 100 will be described later.

  In addition, the recording paper 9 after fixing moved by the transfer device 53 is finally transferred to the fixing device 40 and introduced into the second casing 80B between the transfer device 53 and the fixing device 40. A first transfer introducing device 55 is arranged. Further, a second transfer introduction device 56 for transferring and introducing the recording sheet 9 after fixing to the conveyance device 100 is disposed between the fixing device 40 and the conveyance device 100. In addition, a discharge conveyance path 57 is provided between the conveyance device 100 and the discharge storage unit 60 for conveying the recording paper 9 discharged (after cooling) from the conveyance device 100 toward the discharge storage unit 60 and discharging it. It has been. Further, the recording paper 9 on which the image is formed on one side is drawn between the midpoint of the discharge conveyance path 57 and a part of the supply conveyance path 50 on the first housing 80A side at the time of double-sided image formation. A reverse conveyance path 70 is provided for sending out the supply and conveyance path 50 after the front and back surfaces are reversed. Furthermore, an operation panel unit 85 is installed outside the upper portion of the second housing 80B in order to perform operation operations such as condition setting, instruction, and confirmation for each operation of the image forming apparatus 1.

  The first transfer introducing device 55 is a belt that winds and rotates an annular transfer belt around a plurality of rolls, and transfers the recording paper 9 after the secondary transfer on the outer peripheral surface portion located at the upper part of the transfer belt. It is comprised by arrange | positioning the transfer apparatus. The second transfer introduction device 56 is configured by using a plurality of conveyance roll pairs, a conveyance guide material, a conveyance belt, and the like. The discharge conveyance path 57 includes a plurality of conveyance roll pairs and conveyance guide materials. The reverse conveyance path 70 is a conveyance path 71 having a sheet conveyance destination changing member at a midpoint of the discharge conveyance path 57 and the recording sheet 9 drawn into the draw path 71 after being temporarily drawn in and stopped. A switchback path 72 that feeds out from the rear end of the hour, a feedout path 73 that feeds the recording paper 9 drawn into the switchback path 72 to the supply conveyance path 50 on the first housing 80A side, and the like. Each of these paths 71 to 73 is composed of a plurality of conveyance roll pairs and conveyance guide materials.

<Operation of Image Forming Apparatus>
Hereinafter, an image forming operation of the image forming apparatus 1 will be described.

  First, a basic image forming operation when a full color image formed by combining the toners of the four colors (Y, M, C, K) on one side of the recording paper 9 in the image forming apparatus 1 is taken as an example. I will explain.

  In this case, when there is an instruction to start a full-color image forming operation (printing), in each of the four image forming apparatuses 10 (Y, M, C, K), each photosensitive drum 11 is first rotated in the direction of the arrow. Each charging device 12 charges the image holding surface of each photosensitive drum 11 to a required polarity and potential. Subsequently, the exposure device 13 is based on the image data separated into the color components (Y, M, C, K) transmitted from the image processing device (not shown) on the image holding surface of the charged photosensitive drum 11. The emitted exposure light LB is irradiated to form an electrostatic latent image of each color component composed of a required potential difference. Subsequently, each developing device 14 (Y, M, C, K) has each color (Y, M, C) charged to a required polarity with respect to the electrostatic latent image of each color component formed on each photosensitive drum 11. , K) is supplied to each of the two components to electrostatically attach the toner. As a result, one of four color (Y, M, C, K) toner images is formed on the image holding surface of the photosensitive drum 11 in each image forming device 11.

  Next, each color toner image formed on each photosensitive drum 11 of each image forming device 10 (Y, M, C, K) is rotated by each primary transfer device 25 in the direction indicated by the arrow of the intermediate transfer device 20. Primary transfer is performed so as to overlap the outer surface of the intermediate transfer belt 21 in order. After the primary transfer is completed, the photosensitive drum 11 is cleaned by the drum cleaning device 16, and then the image holding surface is discharged by the charge eliminator 17, thereby preparing for the next image forming step.

  Subsequently, in the intermediate transfer unit 20, the toner image primarily transferred to the intermediate transfer belt 21 is held and conveyed to the secondary transfer position, and then conveyed to the secondary transfer position from the paper feeding device 30 through the supply conveyance path 50. The toner image on the intermediate transfer belt 21 is secondarily transferred to the recording paper 9 to be transferred at once by the secondary transfer device 25. After the secondary transfer is completed, the outer surface of the intermediate transfer belt 21 is cleaned by a belt cleaning device (not shown) to prepare for the next intermediate transfer step.

  Subsequently, the recording paper 9 onto which the toner image has been secondarily transferred is peeled off from the intermediate transfer belt 21 and then transferred by the transfer device 53 and the first transfer introducing device 55 to be introduced into the fixing device 40, and the fixing device 40. The toner image is fixed by receiving a necessary fixing process (heating and pressing). After the fixing is completed, the recording paper 9 is transferred by the second transfer introducing device 56 and introduced into the conveying device 100, and is conveyed while being cooled in the conveying device 100 and discharged. Since the recording paper 9 after being discharged from the conveying device 100 (after cooling) is an image forming operation that only forms an image on one side thereof, it is discharged to the outside of the second casing 100 through the discharge conveying path 57. And accommodated in the discharge accommodating portion 60.

  With the above operation, the image forming apparatus 1 outputs the recording paper 9 on which a full color image formed by combining the four color toner images is formed on one side. When there is an instruction for a plurality of image forming operations, the above-described series of operations are similarly repeated for the number of sheets. When a black and white image composed of black (K) toner is formed, the black (K) image forming device 10K among the plurality of image forming devices 10 operates in the above-described series of operations. By executing the forming operation, the recording paper 9 on which the monochrome image is formed on one side is output.

  Next, a case where images are formed on both the front and back sides of the recording paper 9 in the image forming apparatus 1 will be described.

In this case, the recording paper 9 after the image forming operation on one side is finished (actually after the completion of fixing) is pulled in the reverse conveyance path 70 by the conveyance destination changing member at a midpoint of the discharge conveyance path 57. Is transported to the switchback path 72 and stopped. Thereafter, the recording paper 9 that has been stopped in the switchback path 72 is sent out from the rear end of the transport to the feed path 73 and is fed into the supply transport path 50 on the first housing 80A side. Thereafter, the above-described image forming operation is similarly performed on the surface (back surface) of the recording paper 9 on which no image is formed, and a desired image is formed.
With the above operation, the recording paper 9 on which images are formed on both the front and back sides is output.

  Next, in the image forming apparatus 1, for example, when performing image formation of the above-described normal colors (the above-described four colors, etc.), a special color toner image composed of the developer of the special colors S1 and S2 is also formed. The operation at that time will be described.

In this case, first, in the image forming apparatuses 10S1 and 10S2, the same image forming operation as that of the image forming apparatus 10 (Y, M, C, K) described above is performed. Special color toner images (S1, S2) are formed on the photosensitive drum 11, respectively. Subsequently, the special color toner images formed by the image forming devices 10S1 and 10S2 are primarily transferred to the intermediate transfer belt 21 of the intermediate transfer device 20 in the same manner as the image forming operation related to the four color toner images described above. After that, the secondary transfer device 30 performs secondary transfer from the intermediate transfer belt 21 to the recording paper 9 (along with other color toner images). Finally, the recording paper 5 on which the special color toner image and the toner image of another color are secondarily transferred is subjected to a fixing process in the fixing device 40 and then cooled via the conveying device 100, and then the second paper. It is discharged outside the casing 80B.
Through the above operation, the recording paper 9 on which a composite image in which the two special color toner images overlap and exist on the entire surface or a part of the full color image (or black and white image) described above is output.

<Configuration of transport device>
As shown in FIGS. 1 and 3, the conveying device 100 includes an upper belt 110 as an annular first belt that is arranged on the upper side in the vertical direction (the direction indicated by the arrow Y of the coordinate axis) and circulates. 110 is a recording sheet which is disposed on the lower side of the upper belt 110 in contact with the outer peripheral surface of 110 (specifically, the outer peripheral surface portion existing on the lower side) and is a sheet-like material to be conveyed between the upper belt 110 The lower belt 120 as an annular second belt that circulates and moves so as to be conveyed with the belt 9 in between, and the contact that is fixedly arranged on the inner peripheral side of the upper belt 110 and that contacts the inner peripheral surface of the upper belt 110 And a heat dissipating member 130 as a fixing member having a surface 132. In particular, the transport apparatus 100 is provided with a cooling function for absorbing and cooling the heat of the recording medium 9 being transported by the heat radiating member 130, and therefore can also be referred to as a cooling apparatus.

  The upper belt 110 and the lower belt 120 are obtained, for example, by molding into an annular belt shape using a resin composition in which an additive such as carbon is mixed with a synthetic resin such as polyimide. As the upper belt 110 and the lower belt 120, a belt having a seam, a belt without a seam, or the like is used.

  The upper belt 110 is rotatably supported by being wound around a plurality of rolls. The upper belt 110 in the first embodiment is supported by being wound around five rolls. The five rolls include a drive roll 112 that applies rotational power to the upper belt 110 for rotation, a tension applying roll 113 that applies tension to the upper belt 110 by pushing the upper belt 110 toward the outer periphery, and an upper belt 110. Support rolls 114, 115, and 116 are used to support at a required position. Further, these five rolls include a support roll 115, a support roll 116, a drive roll 112, a support roll 114, and a tension applying roll 113 along a path in which the upper belt 110 circulates from the upstream side in the movement direction of the upper belt 110. They are arranged in order, and are arranged in a positional relationship that secures a space for arranging the heat dissipation member 130 on the inner peripheral side of the upper belt 110.

  The drive roll 112 is disposed so as to be positioned on the exit side (the right end side in FIGS. 1 and 3) for discharging the recording sheet 9 to be conveyed. The tension applying roll 113 is disposed at a position farthest from the driving roll 112 and presses the upper belt 11 from the inner peripheral surface toward the outer peripheral surface side by using the elastic force of the elastic member 117 such as a compression spring. Arranged in a state. The support roll 116 is disposed at a position where the inner peripheral surface of the upper belt 110 forms a substantially smooth region for making contact with the contact surface 132 of the heat radiating member 130 in cooperation with the drive roll 112. In the first embodiment, in FIG. 3 and the like, the smooth region of the upper belt 110 that is in contact with the contact surface 132 of the heat radiating member 130 is positioned so that the end on the outlet side is located above the end on the inlet side It is configured as a region inclined to the right shoulder. Further, the support roll 115 is arranged at a position above the support roll 116 in order to form an entrance space (upper space) of the recording paper 9 to be introduced.

  On the other hand, the lower belt 120 is rotatably supported by being wound around a plurality of rolls. The lower belt 120 in the first embodiment is supported by being wound around five rolls. The five rolls include a drive roll 122 that rotates by applying rotational power to the lower belt 120, a tension applying roll 123 that applies tension to the lower belt 120 by pushing the lower belt 120 toward the outer periphery thereof, and the lower belt 120. Support rolls 124, 125, and 126 are used to support at a required position. In addition, these five rolls include a support roll 125, a support roll 126, a drive roll 122, a support roll 124, and a tension applying roll 123 along a path along which the lower belt 120 circulates from the upstream side in the movement direction of the lower belt 120. Arranged in order.

  The driving roll 122 is located on the exit side for discharging the recording paper 9 to be conveyed and is disposed so as to face the driving roll 112 (with the upper belt 110 and the lower belt 120 interposed). The tension applying roll 123 is disposed at a position farthest from the drive roll 122 and presses the lower belt 12 from the inner peripheral surface toward the outer peripheral surface side by using the elastic force of an elastic member 127 such as a compression spring. Arranged in a state. Further, the support roll 126 is disposed at a position that forms a region for making contact with the outer peripheral surface of the upper belt 110 in cooperation with the drive roll 122. The support roll 125 is disposed at a lower position than the support roll 126 in order to form an entrance space (lower space) of the recording paper 9 to be introduced.

  For the support roll 126, the elastic force of the elastic member 128 such as a compression spring is used to bring the lower belt 120 into contact with the outer peripheral surface of the upper belt 120 and to bring the upper belt 110 into contact with the contact surface 132 of the heat radiating member 130. The lower belt 120 is pressed from the inner peripheral surface using The support roll 126 is configured, for example, as a roll that contacts the inner peripheral surface of the lower belt 120 with a width (length) shorter than the belt width BW in the width direction of the lower belt 120 (direction orthogonal to the circulating movement direction). (See FIG. 7).

  Here, the upper belt 110 rotates so as to circulate and move in the direction indicated by the arrow in the state of being wound around the five rolls by the rotational power applied from the drive roll 112. On the other hand, the lower belt 120 rotates so as to circulate and move in the direction indicated by the arrow when it is wound around the five rolls by the rotational power applied from the drive roll 122. Further, the lower belt 120 moves while being in contact with the outer peripheral surface of the upper belt 110 in a section from the support roll 125 to the drive roll 122. Rotational power is transmitted to the drive roll 112 and the drive roll 122 from a rotary drive device (not shown).

  The recording paper 9 to be transported is introduced into a position (entrance) where the upper belt 110 supported by the support roll 116 and the lower belt 120 supported by the support roll 126 start to come into contact with each other. The upper belt 110 supported by the drive roll 112 and the lower belt 120 supported by the drive roll 122 begin to separate from each other while being transported along the circulation movement direction of each belt while being sandwiched between the belt 110 and the lower belt 120. It is discharged from the position (exit part). In the transport device 100, as shown in FIG. 3, the introduction guide member 141 that smoothly guides the recording paper 9 toward the inlet portion is made to approach the lower belt 120 portion supported by the support roll 125. It is provided in an inclined state. Further, in the transport apparatus 100, as shown in FIG. 3, a pair of discharge guide members 142A and 142B for guiding the recording sheet 9 discharged from the outlet portion to be discharged toward a required direction are provided with a drive roll. The upper belt 110 supported by 112 and the lower belt 120 supported by the drive roll 122 are provided close to each other.

  The heat radiating member 130 has a contact surface 132 that comes into contact with the inner peripheral surface of the upper belt 110, and a plate-like contact portion 131 that conducts heat absorbed by the recording paper 9 through the upper belt 110 to absorb (heat absorption). In the upper part of the contact portion 131, a heat radiating portion 133 that releases heat absorbed by the contact portion 131 is formed.

  The contact portion 131 has a contact surface 132 formed of a curved surface having a predetermined curvature that protrudes toward the inner peripheral surface of the upper belt 110. The heat dissipating part 133 is composed of a plurality of heat dissipating plates or a plurality of heat dissipating rods that stand at intervals above the contact part 131. The contact portion 131 and the heat radiating portion 133 are made of a material having better thermal conductivity than the upper belt 110, and are made of a metal material such as aluminum, for example.

  In addition, an exhaust device (not shown) for sucking and discharging the air present in the heat radiating portion 133 of the heat radiating member 130 is disposed on one side surface of the transport device 100. The exhaust device draws out air existing in the heat radiating portion 133 and the like of the heat radiating member 130 to remove heat from the heat radiating portion 133 and the like, and discharges the hot air to the outside of the transfer device 100 and further to the outside of the second casing 80B. It is like that. For example, an exhaust (intake) fan is used as the exhaust device. A ventilation duct (not shown) that allows air to pass therethrough as necessary is provided between the exhaust device and the heat radiating portion 133 of the heat radiating member 130.

  Further, in the conveying apparatus 100, the tension applying roll 113 in the upper belt 110 and the tension applying roll 123 in the lower belt 120 are configured to change the behavior of the upper belt 110 and the lower belt 120 in a meandering manner (including deviation running). It is also configured as a meandering correction roll (this type of roll is also referred to as a “steering roll”) for correcting by changing.

  Specifically, the tension applying roll 113 and the tension applying roll 123 are moved by a predetermined amount in the correction direction (for example, the direction orthogonal to the pressing direction for applying tension) in accordance with the meandering state of one end of each axial direction. Thus, the entire roll is supported so as to be inclined by a predetermined angle. Further, the tension applying roll 113 and the tension applying roll 123 are respectively connected to a movement drive device (displacement device) (not shown) that moves one end portion (bearing or the like) of each shaft by a required amount in the correction direction. Further, as shown in FIG. 3, the transport device 100 is provided with a first detection sensor 119 and a second detection sensor 129 that detect each meandering state (end position) of the upper belt 110 and the lower belt 120. . As the first detection sensor 119 and the second detection sensor 129, for example, there are detection rods that always contact each end of the upper belt 110 and the lower belt 120 and follow the meandering movement of the belts 110, 120. A type having the detection rod and detecting the position of the belt end from the state in which the elastic detection rod is displaced is used. Further, the tension applying roll 113 and the tension applying roll 123 are configured so that the movement driving device operates according to the detection information of the first detection sensor 119 and the detection information of the second detection sensor 129, respectively, so that one end portion of each axis Is configured to be moved by a required amount in the correction direction.

  As shown in FIG. 4A, the tension applying roll 113 that also functions as a meandering correction roll has its one end (the left end in FIG. 4) moved and tilted in the upward correction direction. The upper belt 110 can be moved to one side (the right side in FIG. 4) in the belt width direction as indicated by a white arrow. Further, as shown in FIG. 4B, the tension applying roll 113 is in a state where one end thereof is moved and tilted in the downward correction direction so that the upper belt 110 is indicated by a white arrow. It can be moved to the other side (left side in FIG. 4) in the belt width direction. In FIGS. 4A and 4B, the reference position of the axis of the tension applying roll 113 before tilting is indicated by a one-dot chain line J0, and the position of the axis of the tension applying roll 113 after tilting is indicated by a one-dot chain line J1 or J2. It is shown in 4 (a) and 4 (b), the black arrow indicates that one side or the other side of the belt width direction of the upper belt 110 with respect to the belt length (circumferential) direction when the tension applying roll 113 is tilted. FIG. 6 schematically shows a state (behavior) that circulates so as to be slightly displaced.

  On the other hand, as shown in FIG. 5 (a), the tension applying roll 123 that also functions as a meandering correction roll has its one end portion (left end portion in FIG. 5) moved in the upward correction direction and tilted. Thus, the lower belt 120 can be moved to one side (the right side in FIG. 5) in the belt width direction. Further, as shown in FIG. 5 (b), the tension applying roll 123 has its one end moved in the downward correction direction and tilted, whereby the lower belt 120 is moved to the other side in the belt width direction ( It can be moved to the left side in FIG. In FIGS. 5A and 5B, the reference position of the axis of the tension applying roll 123 before tilting is indicated by a one-dot chain line K0, and the position of the axis of the tension applying roll 113 after tilting is indicated by the one-dot chain line K1 or K2. It is shown in In FIGS. 5A and 5B, the black arrow indicates that the lower belt 120 is slightly displaced to one side or the other side in the belt width direction with respect to the belt length direction when the tension applying roll 123 is tilted. FIG. 2 schematically shows a state of circular movement.

  Further, as shown in FIG. 3, the transport device 100 is configured as an upper unit 102 by attaching an upper belt 110, five rolls 112 to 116, a heat radiating member 130, and the like to a common support member, while a lower belt 120. Five rolls 122 to 126 are attached to a common support member to form the lower unit 103, thereby adopting a structure in which the whole is divided into two substantially vertically.

  The support member 143 in the upper unit 102 connects, for example, a pair of side frames 143 (FIG. 3) arranged to support both ends of the shafts 112 a of the rolls 112 to 116, and the pair of side frames. It consists of a support arm and the like. Incidentally, the pair of side frames of the support member 143 are connected to the heat radiating portion 133 of the heat radiating member 130 so as to face each other, and a ventilation duct (not shown) that allows air (flow) generated during intake by the exhaust device described above to pass therethrough. Has been placed. On the other hand, the support member 144 in the lower unit 103 includes, for example, a pair of side frames 144 (FIG. 3) arranged to support both ends of the shafts 122 a of the rolls 121 to 126 and the pair of side frames. It is composed of a supporting arm to be connected.

  In addition to this divided structure, the conveying device 100 is in a state where the upper unit 102 is separated from the lower unit 103 and opened, and the outer peripheral surface of the upper belt 110 and the outer peripheral surface of the lower belt 120 are separated from each other. An open / close mechanism is used to achieve this. This opening / closing mechanism is used, for example, when performing an operation of removing the recording paper 9 jammed between the upper belt 110 and the lower belt 120, an inspection operation, an exchange operation, and the like.

  In the transport device 100, as shown in FIGS. 6 and 7, the entrance region 132d where the upper belt 110 starts to contact or the upper belt 110 finishes passing through the contact surface 132 of the heat radiating member 130 which is a fixing member. A sheet material 160 having a dynamic friction coefficient μ (s) smaller than the dynamic friction coefficient μ (h) of the contact surface 132 of the heat dissipation member 130 with respect to the inner peripheral surface of the upper belt 110 is fixed to the outlet region 132e. In the first embodiment, the case where the sheet material 160 is fixed to the entrance region 132d is illustrated.

  6 and 7, reference numeral SP denotes a position of the contact surface 132 where the upper belt 110 starts to contact (contact start position), and reference numeral EP denotes a position of the contact surface 132 where the upper belt 110 finishes contacting (contact end position). ) Respectively. Reference numerals 110a and 110b in FIG. 7 indicate an end portion of the upper belt 110 on the front side of the apparatus and an end portion on the rear side of the apparatus, respectively. Further, in FIG. 6 and the like, symbol BW indicates the width of the upper belt 110, and symbol HW indicates the width of the contact surface 132 of the heat radiating member 130 in the direction orthogonal to the belt moving direction C. Furthermore, a portion indicating the length HL of the contact surface 132 shown in FIG. 7 (including FIG. 9 described later) is a portion that can actually contact the upper belt 110 in a strict sense. In FIG. 6, the contact surface 132 of the heat radiating member 13 is drawn in a state slightly separated from the inner peripheral surface of the upper belt 110 for the sake of facilitating identification of each component, but is actually in contact.

  The entrance region 132d of the contact surface 132 has a length HL in the moving direction C of the upper belt 110 of the contact surface 132 at the maximum from the contact start position SP with the upper belt 110, as indicated by a dotted line or the like in FIG. Only the dimension that is 1/3, preferably the dimension that is 1/5 of the length HL, is the region up to the position where the upper belt 110 enters the downstream side in the moving direction C. On the other hand, the exit area 132e of the contact surface 132 is at most 1 / of the length HL of the upper belt 110 of the contact surface 132, as shown by a dotted line in FIG. It is the region up to the position where it has entered the upstream side in the movement direction C of the upper belt by the distance of 3 and preferably the dimension of 1/5 of the length HL. Reference numeral 132f in FIG. 7 indicates the remaining area (center area) excluding the entrance area 132d and the exit area 132e in the area in contact with the upper belt 110 of the contact surface 132.

  In the first embodiment, the sheet material 160 is moved in the moving direction C of the upper belt 110 by a distance that is a value that is 1/3 of the length HL of the contact surface 132 from the contact start position SP with the upper belt 110 of the contact surface 132. It fixes to the entrance area | region 132d to the position which entered downstream. The sheet material 160 has a dynamic friction coefficient μ (s) having a value 0.2 to 0.58 times the dynamic friction coefficient μ (h) of the contact surface 132 of the heat radiating member 130 with respect to the inner peripheral surface of the upper belt 110. The sheet that has it is used. As such a sheet material 160, a sheet (film) having a thickness of 0.1 to 0.3 mm made of a material such as a fluororesin (for example, Teflon (registered trademark)) can be used. Further, the sheet material 160 is fixed to a corresponding region (in this example, the entrance region 132d) on the contact surface 132 of the heat radiating member by a fixing means such as a pressure-sensitive adhesive tape.

  Incidentally, the dynamic friction coefficient μ (s) of the sheet material 160 is measured according to the measurement method of Japanese Industrial Standard (JIS) K 7125. The dynamic friction coefficient μ (h) of the contact surface 132 of the heat radiating member 130 is also measured according to the measurement method of JIS K 7125.

<Operation of transport device>
Hereinafter, the operation of the transport apparatus 100 will be described.

  First, when the operation time of the conveying device 100 arrives, the upper belt 110 in the upper unit 102 rotates in the direction indicated by the arrow by driving the driving roll 112, while the operation time in the lower unit 103, as shown in FIG. The lower belt 120 rotates in the direction indicated by the arrow by driving the drive roll 122.

  At this time, when the upper belt 110 passes between the support roll 116 and the drive roll 112, the belt inner peripheral surface moves while being in contact with the contact surface 132 of the contact portion 131 in the heat radiating member 130. Further, when the lower belt 120 passes between the support roll 126 and the drive roll 122, the lower belt 120 moves while the outer peripheral surface thereof is in contact with the outer peripheral surface of the upper belt 110. Incidentally, at this time, the intake device (not shown) that assists the heat dissipation of the heat dissipation member 130 also starts its intake operation.

  Subsequently, the recording sheet 9 after the (heat) fixing by the fixing device 40 is completed in various image forming operations is introduced into the transport device 100 thus started.

  At this time, in the conveying apparatus 100, the recording sheet 9 after the fixing is guided by the introduction guide member 141 and introduced from the entrance portion where the upper belt 110 and the lower belt 120 start to contact with each other, It is conveyed while being sandwiched between the lower belts 120. Further, in the transport apparatus 100, the heat of the transported recording paper 9 is dissipated while the heat radiating member 130 absorbs heat via the upper belt 110, and the recording paper 9 is cooled while being transported.

  Finally, the transport device 100 discharges the recording paper 9 from the exit portion where the upper belt 110 and the lower belt 120 start to separate from each other, and guides the recording paper 9 with the pair of discharge guide materials 142A and 142B (exhaust transport path 57). To discharge. As a result, the fixed recording paper 9 is discharged in a cooled state by the conveyance of the conveyance device 100.

  Further, in the transport apparatus 100, when the first detection sensor 119 detects that the end position of the upper belt 110 is displaced from the reference position, the first detection sensor 119 detects the first position as illustrated in FIG. Depending on the detection information of the detection sensor 119, one end of the tension applying roll 113 moves by a required amount in the direction to be corrected, thereby correcting the meandering (offset) of the upper belt 110. On the other hand, when the second detection sensor 129 detects that the end position of the lower belt 120 is displaced from the reference position, the detection information of the second detection sensor 129 is displayed as illustrated in FIG. In response, one end portion of the tension applying roll 123 moves in a direction to be corrected by a required amount, thereby correcting the meandering (offset) of the lower belt 120.

  In the conveying device 100, during the operation, the inner peripheral surface of the upper belt 110 is worn while moving while being in contact with the contact surface 132 of the contact portion 131 in the heat exhausting member 130 that is fixedly disposed. Wear powder is likely to be generated. However, in the transport device 100, the dynamic friction coefficient μ (s) smaller than the dynamic friction coefficient μ (h) of the contact surface 132 is given to the entrance region 132d of the contact surface 132 of the contact portion 131 in the heat removal member 130 as described above. Since the sheet material 160 to be shown is fixed, even though the inner peripheral surface of the upper belt 110 is in contact with and passes through the contact surface 132 of the contact portion 131, wear powder is generated due to wear due to the contact. Hard to do. According to the study by the present inventors, the wear powder is a material mainly composed of polyimide resin, carbon, or the like constituting the upper belt 110, and most of the wear powder is missing due to wear on the inner peripheral surface of the upper belt 110. It has been confirmed that

  As a result, in the conveying apparatus 100, the wear powder is prevented or suppressed from being carried by the upper belt 110 and particularly adhering to the surface of the meandering correction / tensioning roll 113 that also functions as a meandering correction roll. The dynamic wear coefficient of the tension applying roll 113 is less likely to decrease over time, the frictional relationship between the surface of the tension applying roll 113 and the inner peripheral surface of the upper belt 110 is well maintained over a long period of time, and the meandering correction by the tension applying roll 113 is performed. (Control) is performed stably.

<Testing on transport device>
First, the state of occurrence of wear powder was confirmed using the transport device 100.

As the transfer device 100, the one having the following configuration was used.
Both the upper belt 110 and the lower belt 120 are formed from a resin composition in which carbon black or the like is added to a polyimide resin, and has a thickness of about 80 μm, a belt circumferential length of about 528 mm, and a belt width BW of about 370 mm. A belt with no (seamless) form was used.
As the meandering correction roll (tension imparting roll) 113 of the upper belt 110 and the meandering correction roll (tension imparting roll) 123 of the lower belt 120, the surface layer made of urethane resin is applied to the cylindrical metal roll base material. The formed roll was used. The tension applied to the belts 110 and 120 of the meandering correction roll 113 and the meandering correction roll 123 was set to about 16.2N.
Further, the static friction coefficients of the meandering correction roll 113 and the meandering correction roll 123 when not in use with respect to the inner peripheral surfaces of the belts 110 and 120 were both about 1.6.

  On the other hand, as the contact portion 131 of the heat radiating member 130, the length HL in the moving direction C of the upper belt 110 of the contact surface 132 is about 75 mm, and the direction orthogonal to the moving direction C of the upper belt 110 of the contact surface 132 is driven. An aluminum member having a rectangular contact surface with a total width HW in the direction of the rotation axis of the roll 112 of about 386 mm was used. The upper belt 110 substantially receives the heat radiation action by the heat radiating member 130 at the central portion 132c (width: about 346 mm) excluding both end portions 132a and 132b (width: 20 mm each) of the contact surface 132 of the contact portion 132. It is like that. Further, the contact surface 132 of the contact portion 131 is formed with a gently curved surface (surface having a predetermined radius of curvature) whose central portion is convex downward (lower belt 120 side) in the moving direction C of the upper belt 110. ing.

  Then, the conveyor 100 having the above-described configuration is continuously operated (rotational speed of each of the belts 110 and 120: about 483 mm / second) for a time when the number of image forming sheets is 800,000 (= 800 kPV), and then The surface states of the meandering correction roll 113 and the meandering correction roll 123 were observed.

  As a result, the surface of the meandering correction roll 113 of the upper belt 110 was dirty, whereas the surface of the meandering correction belt 123 of the lower belt 120 was almost not dirty and was in a state close to the initial state. confirmed. Moreover, when the deposit | attachment which is the cause of the stain | pollution | contamination of the meandering correction | amendment roll 113 was extract | collected and the component was analyzed, it turned out that the main component is carbon black which is the resin component of polyimide, and its additive. As a result, the deposits that cause dirt on the meandering correction roll 113 are worn away due to the contact of the inner peripheral surface (the constituent material) of the upper belt 110 with the contact surface 132 of the contact portion 131 of the heat radiating member 130. It can be inferred that it is a worn powder.

  Further, when the static friction coefficients of the meandering correction roll 113 and the meandering correction roll 123 after this test were measured, the values were about 0.6 and about 1.2.

  FIG. 8 shows each static friction coefficient with respect to the upper belt 110 of the upper meander correction roll 113 in the unused stage (New) and after the test (Age), and the lower meander in the unused stage and after the test. The measurement result with each static friction coefficient with respect to the lower belt 120 of the correction | amendment roll 123 is shown. From the measurement results, the static friction coefficients of the meandering correction roll 113 and the meandering correction roll 123 were substantially the same value in the unused stage, but the lower meandering correction 123 was about 25% after the test. It can be seen that the upper meandering correction roll 113 is greatly reduced by about 63%. Incidentally, it can be said that the reason why the coefficient of static friction of the upper meandering correction roll 113 is greatly reduced is that the wear powder adheres to the roll surface.

  Next, as the conveying device 100 having the above-described configuration (in an unused stage), as shown in FIG. 9, the same type (width and length dimensions) as the sheet material 160 is provided at various positions of the contact portion 131 in the heat dissipation member 130. Are prepared), and the conveying device 100 is continuously operated as long as the number of image forming sheets is 1500 (= 1.5 kPV) as in the previous test. Then, the degree of contamination due to adhesion of abrasion powder between the contact surface 132 of the heat radiating member 130 and the upper meandering correction roll 113 was examined.

  Here, as the test sheet 165, one having a dynamic friction coefficient μ (s) of about 0.04 with respect to the inner peripheral surface of the upper belt 110 was used. The dynamic friction coefficient μ (h) of the contact surface 132 in the contact portion 131 of the heat radiating member 130 was about 0.5 to 0.1.

  Further, the contact surface 132 of the heat radiating member 130 has six test areas A to F (width: about 80 mm, length: about 75 mm) obtained by dividing the central region 132 c into approximately six equal parts in the width HS direction. The test sheets 165A to 165 and E to F were fixed (attached) to predetermined positions in the test zones A to C and E to F, respectively, except for the test zone C.

Specifically, the test sheet 165A is a sheet having a width of about 70 mm and a length (dimension in the belt movement direction C) of about 15 mm, and is on the exit side of the test area A (downstream in the belt movement direction C). Side) end region.
The test sheet 165B is a sheet having a width of about 80 mm and a length of about 20 mm, and is shifted by about 15 mm from the end on the inlet side (upstream side in the belt movement direction C) of the test area B to the outlet side. Fixed in position.
The test sheet 165C was a sheet having a width of about 80 mm and a length of about 10 mm, and was fixed to the end area on the entrance side of the test area C.
Each of the test sheets 165D1 and 165D2 is a sheet having a width of about 80 mm and a length of about 10 mm, and is fixed to the end area on the inlet side and the end area on the outlet side of the test area E, respectively.
The test sheet 165E was a sheet having a width of about 80 mm and a length of about 20 mm, and was fixed at a substantially central position in the length direction of the test area F.
The test area C is an area where the pressing support rolls 126 are arranged in a substantially overlapping positional relationship, and is an area where the test sheet 165 is not attached at all.

Any surface contamination of the contact surface 132 of the heat radiating member 130 and the upper meandering correction roll 113 due to adhesion of abrasion powder is the surface of the contact surface 132 and the meandering correction roll 113 corresponding to the test areas A to F. The state was observed and the results were evaluated according to the following criteria.
○: No wear powder is adhered (no generation of wear powder is observed).
Δ: Generation of wear powder is observed, but wear powder adheres very little.
X: Abrasion powder adheres to such an extent that it can be easily visually recognized.

  FIG. 10 shows the test results regarding the degree of contamination. In FIG. 10, “Δ˜ ×” indicates a case where a location where the evaluation result is “Δ” and a location where “×” is present depending on the location of the meandering correction roll 113. .

  From this test result, the contamination on the surface of the upper meandering correction roll 113 indicates that the entrance region of the contact surface 132 of the heat radiating member 130 in the test sheet 165 (the sheet material 160) is the test area C. It can be seen that almost no occurrence occurs when the region is fixed to the region included in 132d.

  Further, regarding the contamination on the surface of the meandering correction roll 113, the test sheet 165 (finally the sheet material 160) is included in the exit area 132 e in the contact surface 132 of the heat radiating member 130 like the test area A. The evaluation result “Δ” that is practically acceptable also when it is fixed to the region and when it is fixed to the region included in the contact surface 132 of the heat radiating member 130 on the downstream side of the inlet region 132d as in the test area B. It can be seen that the level can be.

  However, when it is fixed to a region included in the downstream side of the inlet region 132d of the heat radiating member 130 as in the test area B, the evaluation result “×” indicates that contamination on the contact surface 132 of the heat radiating member 130 is practically unacceptable. In consideration of this point, it can be said that the effect is inferior to the case where the test area A is fixed. When this point is regarded as important, when the test sheet 165 (finally, the sheet material 160) is fixed to a region included in the outlet region 132e of the contact surface 132 of the heat dissipation member 130 like the test region A, Although it is a little inferior to the case where it is fixed to the area included in the entrance area 132d as in the test area C, it can be seen that good results are obtained.

  In addition, the transport apparatus 100, like the test area A, when the test sheet 165 (finally the sheet material 160) is fixed to an area included in the entrance area 132d as in the test area C. Compared with the case where the heat dissipation member 130 is fixed to the region included in the outlet region 132e in the contact surface 132, the heat dissipation performance by the heat dissipation member 130 can be obtained better.

This is presumably due to the following reasons.
First, the heat of the recording paper 9 discharged (or conveyed) from the fixing device 40 is transferred to the upper belt 110 by heat conduction generated by a temperature difference between generally contacting objects, and then contacts the upper belt 110. It is transmitted to the heat radiating member 130 of the fixed member.
On the other hand, in the transport device 100, the upper belt 110 moves toward the exit side in the transport direction of the recording paper 9, so if there is no recording paper 9 anywhere, the upper belt 110 is moved to the heat dissipation member 130. The heat of the recording paper 9 is first transferred to the outer surface of the upper belt 110 at the time when it is in the entrance region of the contact surface 132, but the heat transfer is performed on the inner surface of the upper belt 110 that contacts the heat radiating member 130. Therefore, it can be said that the temperature is not increased.
After that, the heat transmitted to the outer surface of the belt is transmitted to the inner surface of the upper belt 110, and when the portion of the upper belt 110 moves to the exit region in the conveying direction, the heat is transferred (moved) to the inner side of the belt. It is considered that the surface has a higher temperature than the belt outer surface.
Further, the portion where the temperature of the upper belt 110 is in direct contact with the heat radiating member 130 (the contact surface 132 thereof) is higher than the case where the sheet material 160 or the like is interposed on the contact surface 132, for example. It is considered that the heat of the belt 110 is well transmitted to the heat radiating member 130 and the heat radiating performance is improved.
From the above, in this conveying apparatus 100, the heat radiation member is more fixed when the sheet member 160 is fixed to the entrance region of the contact surface 132 of the heat dissipation member 130 than when it is fixed to the exit region of the contact surface 132. It is estimated that the heat dissipation performance by 130 becomes high and becomes advantageous.

  Further, when the conveyance device 100 fixes the test sheet 165 (finally, the sheet material 160) to the entrance region of the contact surface 132 of the heat radiating member 130, the transport device 100 fixes the test sheet 165 to the exit region of the contact surface 132. In comparison, since the heat of the recording paper 9 on which the sheet material 160 is conveyed is less likely to become a high temperature, deterioration of the sheet material 160 due to the heat can be suppressed, and generation of wear powder can be suppressed over a long period of time. It becomes possible.

[Other embodiments]
In the transport apparatus 100 according to the first embodiment, instead of the heat radiating member 130, for example, a fixing member made of a heating member having a contact surface in contact with the inner peripheral surface of the upper belt 110 may be disposed. As the heating member, for example, a member constituted by a heating source and a structure equipped with the heating source can be applied. When configured in this manner, the recording paper 9 conveyed by the conveying device 100 is heated by the heat from the heating member transmitted through the upper belt 110 during the conveyance.

  Moreover, in the conveying apparatus 100 which concerns on Embodiment 1, it replaces with the pressing member comprised with the lower belt 120 and its several support rolls (122-126), for example, is heat radiation among the outer peripheral surfaces of the upper belt 110. A member or a plurality of members (fixed members) are arranged so as to rotate while being in contact with a portion passing through the contact surface, and the sheet-like recording paper 9 is sandwiched between the upper belt 110 and the sheet or recording paper 9 is conveyed. You may employ | adopt the pressing member comprised with a pressing roll. Incidentally, the arrangement and types of the plurality of support rolls that support the upper belt 110 and the plurality of support rolls that support the lower belt 120 may be other configurations than those illustrated in the first embodiment. . Further, the tension applying rolls 113 and 123 may be configured as tension applying rolls having only the function of applying tension without having the function of correcting meandering. In this case, a meandering correction roll having a meandering correction function may be provided in addition to the tensioning toll having only the tensioning function.

  Furthermore, in the image forming apparatus 1 according to the first embodiment, a case where the transport device 100 is used as a device for transporting the recording paper 9 after fixing by the fixing device 40 (in other words, after an image is formed) is shown. However, in addition, for example, the transport device 100 can be configured to be used alone or used together as a device for transporting the recording paper 9 before the image is formed.

  In addition, as long as the image forming apparatus 1 can apply the transport apparatus 100, the image forming method, the structure thereof, and the like are not particularly limited. If necessary, an image forming apparatus that forms an image made of a material other than the developer may be used. Further, the conveying device 100 is not limited to the case where the conveying device 100 is used by being incorporated in the image forming apparatus 100. For example, the conveying device 100 can be used alone as the conveying device 100 for conveying a sheet-like material to be conveyed, You may comprise so that it may be used in combination with the other kind of apparatus which handles a conveyance material.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 9 ... Recording paper (an example of a sheet-like conveyed material or recording medium)
100 ... Conveying device 110 ... Upper belt (an example of a belt)
113 ... Meander correction and tension applying roll (an example of tension applying roll)
120... Lower belt (part of parts constituting pressing member / example of second belt)
122 to 126 ... support roll (a part of the parts constituting the pressing member)
130 ... Heat dissipation member (an example of a fixing member)
132 ... Contact surface 132d ... Inlet region 132e ... Outlet region 160 ... Sheet material C ... Upper belt moving direction SP ... Contact surface upper belt contact start position EP ... Contact surface upper belt contact end position

Claims (6)

An annular belt that circulates,
A tension applying roll that is wound around the belt and applies tension to the belt by pushing the belt toward the outer periphery;
A fixing member that is fixedly disposed on the inner peripheral side of the belt and has a contact surface that contacts the inner peripheral surface of the belt;
A pressing which is arranged on the outer peripheral side of the belt and presses the belt against the contact surface of the fixing member and presses a sheet-like material to be conveyed to a portion of the outer peripheral surface of the belt passing through the contact surface of the fixing member Members,
With
A dynamic friction coefficient smaller than a dynamic friction coefficient with respect to the inner peripheral surface of the belt on the contact surface of the fixing member is shown in an entrance region where the belt starts to contact or an exit region where the belt finishes passing among contact surfaces of the fixing member. A conveying device characterized in that a sheet material is fixed.   The transport apparatus according to claim 1, wherein the transport material is transported from a fixing device that thermally fixes an image formed on the sheet-shaped transport material.   The transport apparatus according to claim 1, wherein the fixing member is a heat radiating member.   The pressing member is disposed in contact with the outer peripheral surface of the belt, and has an annular second belt that circulates and transports the sheet-shaped material to be conveyed with the belt interposed therebetween. The conveying device according to claim 1. The entrance area of the contact surface of the fixing member enters the downstream side in the moving direction of the belt by a dimension that is a maximum of the length of the contact surface in the moving direction of the belt at the maximum from the contact start position. The area up to the position,
The exit area of the contact surface of the fixing member reaches the upstream side in the moving direction of the belt by a distance of 1/3 of the length of the contact surface in the moving direction of the belt at the maximum from the contact end position with the belt. The conveying device according to claim 1, wherein the conveying device is a region up to the position.   6. An image comprising the conveying device according to claim 1 as a conveying device that conveys at least one sheet-like recording medium before and after the image is formed. Forming equipment.

Images