JP2006016164A - Conveyance roller of image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance roller of an image forming device capable of preventing coming-near to the direction of a conveyance roller shaft of a conveyed object and occurrence of wrinkle and waving of the conveyed object. <P>SOLUTION: In this conveyance roller arranging a plurality of minute projections biting on a surface layer of the conveyed object and using kicking-out force for the conveyed object as conveyance force of the conveyed object on a surface, height of the minute projections can be changed depending on a central part and both end parts of the conveyed object in the axial direction. In the conveyance roller arranging the plurality of minute projections on the surface, the direction of conveyance by the minute projections in both end parts in the axial direction is directed to the direction of conveyance to the direction of outer side relative to the direction of conveyance of the conveyed object. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to various belt-shaped conveying devices in image forming apparatuses such as printers and copying machines, and image reading apparatuses such as document feeders. In particular, the present invention relates to a transport roller that drives a belt of the belt-shaped transport device.

  An image forming apparatus according to the prior art will be described with reference to the image forming apparatus and the belt-shaped conveying device shown in FIGS.

  Here, as a belt-like conveyance device, a transfer conveyance belt using a belt for conveying a sheet material and transferring a latent image to a sheet material will be described.

  As shown in FIG. 3, a sheet feed roller 311 for feeding the sheet material P stacked and stored in the sheet feed tray 312 of the image forming apparatus 300 in order from the topmost sheet is 1 in the clockwise direction a. Rotate to stop rotating. The feed length of the sheet material P is determined by the peripheral length of the contact portion of the sheet feed roller 311 with the sheet material P.

  When the sheet feeding roller 311 rotates in the direction a by the start of sheet feeding, the leading end side of the uppermost sheet material contacts the rotating sheet feeding roller 311 and is fed out in the direction b.

  The sheet material P is conveyed by the sheet feeding roller 311 until it is transferred to the next conveying means.

  Next to the sheet feeding device 310, the sheet material P is sent to a registration roller unit including a registration roller 313 and a registration roller 314. The sheet material P sandwiched between the registration roller 313 and the registration roller 314 and conveyed from the registration roller unit detects the timing of the leading end position by the sensor 315, and then is sent to the image forming unit 316.

  The sheet material P fed from the registration roller unit is brought into close contact with the transfer conveyance belt by the transfer conveyance belt 304 of the belt conveyance device 302. As shown in FIGS. 4 to 6, the belt conveying device 302 has a transfer roller 303 that conveys the transfer conveying belt 304 by a driving source (not shown) and a sheet material P in close contact with each other, and transfers the image to the image forming unit. The position of the transfer conveyance belt 304 is determined together with the conveyance belt 304 and the conveyance roller 303, and the driven roller 305 that is driven to rotate by the conveyance of the transfer conveyance belt 304, the slackness of the transfer conveyance belt 304 spanned between the conveyance roller 303 and the driven roller 305. The tension roller 306 is configured to prevent the above-described problem and increase the conveying force of the conveying roller 303.

  As shown in FIG. 3, the sheet material P adhered on the transfer conveyance belt conveyed in the d direction is conveyed to a predetermined position by the conveyance roller 303 rotating in the e direction. Then, in the image forming unit 316, the original image formed on the photosensitive belts 317A and 317B is transferred and recorded on the surface of the sheet material P using the respective transfer rollers 318A and 318B. The sheet material P on which the original image is transferred and recorded is conveyed again while being in close contact with the transfer conveyance belt 304, and after being separated from the transfer conveyance belt, is conveyed to the fixing device.

  The speeds of the photosensitive belts 317A and 317B moving in the c direction and the speed of the transfer conveyance belt 304 moving in the d direction must match, and high conveyance accuracy is required for conveyance of the transfer conveyance belt 304.

  In the fixing device, the original image on the sheet material is fixed, and then the sheet material P is discharged as it is to each paper discharge unit, and a series of recording operations is completed.

  Schematic diagrams of means for ensuring the conveyance position accuracy of the transfer conveyance belt 304 are shown in FIGS.

  In FIG. 4, flanges 303 b are provided on the flange portions of the transport roller 303 and the driven roller 305 to restrict the position in the axial direction. However, when the belt material is thin or the rigidity is weak, the regulating force is weak. The transfer belt feeding accuracy in the d direction is determined by the tension between the belt and the frictional force between the conveying roller / driven roller using rubber or elastic resin and the belt.

  In FIG. 5, a guide hole 304 a is provided in the transfer conveyance belt 304, and alignment in the axial direction and the feed direction is performed by matching with the belt guide 303 c provided in the conveyance roller 303 and the driven roller 305. When the length of the transfer conveyance belt in the axial direction is long, as in the case of FIG. 4, in order to increase not only the belt tension but also the frictional force between the conveyance roller / driven roller and the belt, rubber or elasticity is used. A conveying roller and a driven roller using a resin having the same are required.

  In FIG. 6, guide ribs 304 b are provided on the transfer conveyance belt 304 and are aligned in the guide grooves 303 d of the conveyance roller 303, the driven roller 305 and the tension roller 306, thereby performing axial alignment. Also in this case, the transfer belt feeding accuracy is determined by the belt tension and the frictional force between the conveying roller / driven roller and the belt using rubber or elastic resin.

  In this way, by providing flanges, guide holes, guide ribs, etc. in order to ensure the accuracy of the transport position of the object to be transported, the cost of parts increases, the accuracy of processing and the processing cost for attaching, etc., are increased. Space is also required.

  Further, in the case of a transported object transport roller using rubber or elastic resin, the transported object is transported by the frictional force between the roller and the transported object. The moving distance of the object does not necessarily match, and the roller slips and the moving distance of the sheet material decreases. Due to changes in the roller material over time, changes in the surrounding environment, and contamination due to abrasion powder etc. of the conveyed object, a significant decrease in the conveying force is observed, and the rotational movement distance of the roller and the conveyed distance of the conveyed object are unstable. In order to ensure the conveyance position accuracy of the object to be conveyed, it is necessary to provide a separate positioning device.

  For this reason, Patent Documents 1 and 2 propose transport rollers in which minute protrusions are provided on the transport roller of the transfer transport belt as a transported object.

  As described in the above publication, there is no need to simply have irregularities as the minute protrusions of the transport roller. As proposed in Patent Document 3, the protrusions have sharp tips that bite into the surface of the object to be transported. Therefore, a directional microprotrusion is required so that the force to kick the object to be conveyed is the conveying force of the object to be conveyed. In this proposal, microprojections are formed by rolling.

Japanese Unexamined Patent Publication No. 6-035331 Japanese Patent Laid-Open No. 10-087103 JP 2000-159377 A

  However, in the case where minute protrusions such as a resin transfer conveyor belt are difficult to bite into the surface of the object to be conveyed and where the tension is large, it is insufficient to ensure the conveyance position accuracy of the object to be conveyed by the minute protrusions. The conveyance object is shifted in the axial direction of the conveyance roller, and wrinkles and undulations of the conveyance object occur.

  The present invention has been made in view of the above problems, and an object of the present invention is an image forming apparatus that can prevent the object to be conveyed from being shifted in the axial direction of the object and the wrinkles or undulations of the object to be conveyed. It is to provide a conveyance roller.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a transfer in which a plurality of micro protrusions are arranged on the surface, the force that bites into the surface of the object to be transferred and kicks the object to be transferred. The roller is characterized in that the height of the minute protrusion is changed between the central portion and both end portions of the conveyed object in the axial direction.

  According to a second aspect of the present invention, in the transport roller in which a plurality of microprojections are arranged on the surface, the transport direction by the microprojections at both ends in the axial direction is defined as the transport direction in the outward direction with respect to the transport direction of the object to be transported. It is characterized by doing.

  According to the present invention, the height of the minute protrusions in the conveying roller in which a plurality of minute protrusions are arranged on the surface, where the force to bite into the surface of the object to be conveyed and the kicking force to the object to be conveyed is the conveying force of the object to be conveyed. By changing the transport direction between the center and both ends of the object to be transported in the axial direction, or by setting the transport direction by the minute projections at both ends in the axial direction to the transport direction in the outward direction with respect to the transport direction of the transport object. By transporting the transported object and positioning the transported object, it has become possible to prevent the transported object from shifting in the axial direction of the transported roller and from wrinkling / waving of the transported object. .

  In addition, it is effective only by changing the height and direction of the microprotrusions, and there is almost no increase in the processing cost, and it can be realized at a low cost.

  In addition, the roller rotation distance and the transported object can be reduced without causing a significant decrease in transport force due to changes in the roller material over time, changes in the surrounding environment, and contamination of the transported object due to abrasion powder, toner, oil, etc. It is possible to match the movement distance, and it is possible to ensure the conveyance position accuracy of the object to be conveyed.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

<Embodiment 1>
1 and 2 show a conveyance roller of the image forming apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 2, in the configuration of the image forming unit having a plurality of image forming means (for example, corresponding to multiple colors), the conveying roller having the minute projections of the present invention is used as the driving conveying roller of the transfer conveying belt. Use.

  Since the conveyance operation mode of the sheet material P in the image forming apparatus is the same as the conventional example described in FIG. 3, the description thereof is omitted.

  In FIG. 1a), in the transport roller 103 having a plurality of microprotrusions 103a on the surface, the microprotrusions that have the transporting force of the transported object as the transporting force of the transported object to the transported object surface layer An example is shown in which the height is changed between the central portion and both end portions of the conveyed object in the axial direction. The relationship between the minute projection height h1 at the center of the conveyed object in the axial direction of the conveyance roller 103 and the minute projection height h2 at both ends thereof is set so that h1 is higher than h2. As a result, the tension on the object to be conveyed changes between the central part and both ends of the object to be conveyed in the axial direction, and the central part becomes higher, so that the object to be conveyed does not move in the axial direction. The position is determined with respect to the transport roller.

  The shape pattern of the height of the minute protrusions in the axial direction of the conveying roller 103 is a step-like pattern that changes intermittently between the center and both ends, and a medium-high curved pattern that changes continuously between the center and both ends. Either way, the function is realized. It is also possible to form a portion without a minute projection between the central portion and both end portions. The difference between the height of the minute protrusion h1 at the center of the object to be conveyed in the axial direction of the conveying roller 103 and the height of the minute protrusion h2 at both ends is only a few tens of μm, depending on the tension and rigidity of the object to be conveyed. For this reason, the accuracy such as the flatness of the conveyed object is not greatly affected.

<Embodiment 2>
On the other hand, in FIG. 1 b), in the conveyance roller in which a plurality of minute protrusions are arranged on the surface, the conveyance direction by the minute protrusions at both ends in the axial direction of the conveyance roller is outside the conveyance direction of the object to be conveyed. The schematic which makes it the conveyance direction to a direction is shown.

  The minute protrusion at the center of the conveyed object in the axial direction of the conveying roller 103 matches the surface that bites the conveyed object with the conveying direction of the conveyed object, that is, the minute protrusion kicks out of the conveyed object. The force Ft is made to coincide with the transport force Fb of the object to be transported, but the microprotrusions at both ends thereof are directed in the outward direction with respect to the transport direction of the object to be transported, and the microprotrusions with respect to the transported object The kicking force Ft is used not only as the transport force Fb of the transported object but also as the moving force Fy of the transported object in the axial direction of the transport roller 103. By configuring the minute protrusion 103a of the transport roller 103 in this way, the same effect as in the first embodiment can be obtained, and the position of the transported object can be changed to the transport roller without moving the transported object in the axial direction. It is determined against.

  The height of the minute protrusion 103a of the conveying roller 103 may be changed between the central portion and both end portions of the object to be conveyed in the axial direction as in the first embodiment, and a further effect can be obtained.

  The present invention is applicable to conveyance rollers that drive belts of various belt-shaped conveyance devices in image forming apparatuses such as printers and copiers, and image reading apparatuses such as document feeders.

It is the schematic explaining the microprotrusion of the conveyance roller which concerns on Embodiment 1 of this invention. It is a schematic block diagram of the belt conveying apparatus using the conveying roller which concerns on Embodiment 1 of this invention. It is a schematic block diagram of the image forming apparatus provided with the belt conveying apparatus using the conveyance roller which concerns on a prior art. It is a schematic block diagram of the belt conveying apparatus using the conveyance roller which concerns on a prior art. It is a schematic block diagram of the belt conveying apparatus using the conveyance roller which concerns on a prior art. It is a schematic block diagram of the belt conveying apparatus using the conveyance roller which concerns on a prior art.

Explanation of symbols

103 Conveying roller 103a Minute protrusion of conveying roller 104 Transfer conveying belt 105 Followed roller 106 Tension roller

Claims (2)

In the transport roller that digs into the surface of the object to be transported and arranges a plurality of minute protrusions on the surface, the force of kicking out the object to be transported is the transport force of the object to be transported,
A conveying roller of an image forming apparatus, wherein the height of the minute protrusion is changed between a central portion and both end portions of an object to be conveyed in the axial direction. In a transport roller that places a plurality of microprojections on the surface,
A conveyance roller of an image forming apparatus, wherein a conveyance direction by minute protrusions at both ends in an axial direction is a conveyance direction in an outward direction with respect to a conveyance direction of an object to be conveyed.

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