JP2015022031A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can ensure the electrical conduction between a first guide member and a second guide member that is fixed thereto, and suppress the occurrence of floating and peeling of a fixation part of both members.SOLUTION: An image forming apparatus 100 includes image forming means (61, 16) for forming images on a recording material P, conveying means (13, 17) for conveying the recording material, and guide means 15 for guiding the recording material conveyed by the conveying means. The guide means includes a first guide member 150 and a second guide member 151 fixed to the first guide member, where the second guide member is fixed to the first guide member with a non-conductive double-sided tape 152 and a conductive double-sided tape 153.

Description

  The present invention relates to an image forming apparatus using an electrophotographic system or an electrostatic recording system.

  2. Description of the Related Art Conventionally, in an image forming apparatus using, for example, an electrophotographic system, an image (toner image) formed with toner on a photosensitive member or an intermediate transfer member as an image carrier is transferred to a recording material such as recording paper by a transfer unit in a transfer unit. Is transcribed. As the transfer means, a corona charger, a roller-shaped transfer member pressed against the image carrier, or the like is used.

  In order to accurately transfer the toner image on the image carrier onto the recording material and obtain a high image quality, it is important that the recording material rushes into the transfer portion well. Management is done. For this purpose, a guide unit is provided on the upstream side of the transfer unit in the recording material conveyance direction to guide the recording material conveyed by the conveyance unit to a good position of the transfer unit. The guide means generally has a pair of conveyance guides disposed on one surface side and the other surface side of the recording material as guide members.

  In addition, a guide sheet which is a thin sheet-like guide member is provided with respect to the conveyance guide so that a recording material can be plunged into the transfer portion while maintaining a desired resistance value, position, angle, and the like. The recording material is guided to the vicinity of the transfer portion (Patent Document 1). For example, the guide sheet is fixed so as to protrude toward the downstream side in the recording material conveyance direction with respect to the conveyance guide on the surface side on which the image of the recording material is transferred.

  The guide sheet is easily charged by being rubbed by the recording material when the recording material is conveyed. When the guide sheet is charged, the toner image on the image carrier may be scattered due to the discharge and the image may be disturbed. Therefore, a guide sheet (conductive sheet member) imparted with conductivity may be used.

JP 2010-85491 A

  In order to ensure the conductivity of the guide sheet, the guide sheet (second guide member) is fixed to the conveyance guide (first guide member) using a conductive double-sided tape, and the guide sheet is electrically passed through the conveyance guide. May be grounded (connected to ground).

  However, it is generally known that a conductive double-sided tape has a lower adhesive force than a non-conductive double-sided tape, and a part of the guide sheet may be lifted or peeled off due to insufficient adhesive force. Due to this, for example, the above-described image defect may occur.

  Therefore, an object of the present invention is to suppress the occurrence of floating and peeling of the fixed portion while ensuring electrical continuity between the first guide member and the second guide member fixed to the first guide member. An image forming apparatus is provided.

  The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention provides an image forming unit that forms an image on a recording material, a conveying unit that conveys the recording material to the image forming unit, and a guide unit that guides the recording material conveyed by the conveying unit. The guide means includes a first guide member and a second guide member fixed to the first guide member, and the second guide member includes: The image forming apparatus is fixed to the first guide member by a non-conductive double-sided tape and a conductive double-sided tape.

  According to the present invention, the electrical connection between the first guide member and the second guide member fixed to the first guide member can be ensured, and the occurrence of floating and peeling of the fixed portion can be suppressed.

1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention. It is sectional drawing of the peripheral part of the secondary transfer part in one Example of this invention. It is the typical top view and side view of the conveyance guide and guide sheet in one Example of this invention. It is the typical top view and side view of a conveyance guide and guide sheet in other examples of the present invention. It is a typical side view for demonstrating the force concerning a guide sheet. It is sectional drawing of the peripheral part of the secondary transfer part in the further another Example of this invention. It is the typical top view and side view of a conveyance guide and guide sheet in other examples of the present invention.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Example 1
1. FIG. 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 100 according to the present exemplary embodiment is a tandem type laser beam printer that employs an intermediate transfer method that can form a full-color image using an electrophotographic method.

  The image forming apparatus 100 includes four process cartridges 7Y, 7M, 7C, and 7K that are detachable from the apparatus main body E. These four process cartridges 7Y, 7M, 7C, and 7K have substantially the same configuration, but are respectively made of yellow (Y), magenta (M), cyan (C), and black (K) toners. It differs in that an image is formed.

  In the following, unless there is a particular need to distinguish, the Y, M, C, and K at the end of the reference numerals in the figure representing elements provided for any color are omitted, and the elements are described in a comprehensive manner. To do.

  The process cartridge 7 has a photosensitive drum 1 which is a drum-type (cylindrical) electrophotographic photosensitive member as a first image carrier. The process cartridge 7 has the following units around the photosensitive drum 1. First, it has the charging roller 2 which is a roller-shaped charging member as a charging means. Next, it has the developing device 4 as a developing means. Next, a drum cleaning device 8 as a photosensitive member cleaning unit is provided. The developing device 4 includes a developing roller 40, a developer application roller 41, and the like. The drum cleaning device 8 includes a cleaning blade, a waste toner container, and the like.

  In the apparatus main body E, a scanner unit 3 as an exposure unit is disposed above the process cartridges 7Y, 7M, 7C, and 7K. The scanner unit 3 performs exposure based on the image signal on the photosensitive drums 1Y, 1M, 1C, and 1K of the process cartridges 7Y, 7M, 7C, and 7K.

  Further, toner units 5Y, 5M, 5C, and 5K for supplying toner to the developing devices 4Y, 4M, 4C, and 4K are connected to the process cartridges 7Y, 7M, 7C, and 7K. The toner unit 5 is detachable from the process cartridge 7 and the apparatus main body E.

  The photosensitive drum 1 is charged with a predetermined potential having a predetermined polarity (negative polarity in this embodiment) by the charging roller 2 and then scanned and exposed by the scanner unit 3. As a result, an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 1. This electrostatic latent image is reversely developed by the developing device 4 to form a toner image. In other words, the exposed portion (image portion) of the photosensitive drum 1 that is exposed after being charged substantially uniformly and exposed to a lower absolute value of the potential has the same polarity (negative polarity in this embodiment) as the charged polarity of the photosensitive drum 1. Toner is deposited to form a toner image.

  For example, when a full color image is formed, the above-described charging, exposure, and development processes are performed in the process cartridges 7Y, 7M, 7C, and 7K, and yellow, magenta, and magenta are respectively applied to the photosensitive drums 1Y, 1M, 1C, and 1K. Cyan and black toner images are formed.

  The intermediate transfer unit 6 is disposed so as to face the photosensitive drums 1Y, 1M, 1C, and 1K of the process cartridges 7Y, 7M, 7C, and 7K. The intermediate transfer belt unit 6 includes an intermediate transfer belt 61 that is an intermediate transfer member constituted by an endless belt as a second image carrier. The intermediate transfer belt 61 is stretched around a driving roller 62 as a stretching roller, a secondary transfer counter roller 63, and a tension roller 64. The tension roller 64 is in the direction of arrow B in the figure (from the inside to the outside of the intermediate transfer belt 61). Tension is applied in the direction toward Further, primary transfer rollers 65Y, 65M, 65C, and 65K, which are roller-shaped transfer members as primary transfer means, are disposed on the inner peripheral surface side of the intermediate transfer belt 61 so as to face the photosensitive drums 1Y, 1M, 1C, and 1K. Is arranged. The primary transfer roller 65 is pressed toward the photosensitive drum 1 via the intermediate transfer belt 61, and forms a primary transfer portion (primary transfer nip) N1 at a contact portion between the intermediate transfer belt 61 and the photosensitive drum 1. Yes. A primary transfer bias is applied to the primary transfer roller 65 by bias applying means (not shown). Further, a secondary transfer roller 16 that is a roller-shaped transfer member as a secondary transfer unit is disposed on the outer peripheral surface side of the intermediate transfer belt 61 so as to face the secondary transfer counter roller 63. The secondary transfer roller 16 is pressed toward the secondary transfer counter roller 63 via the intermediate transfer belt 61, and a secondary transfer portion (secondary transfer portion (secondary transfer roller 16) is brought into contact with the intermediate transfer belt 61 and the secondary transfer roller 16. Transfer nip) N2 is formed. A secondary transfer bias is applied to the secondary transfer roller 16 by a bias applying means (not shown).

  The toner image formed on the photosensitive drum 1 is conveyed to the primary transfer portion N1 as the photosensitive drum 1 rotates in the direction of arrow D in the figure. Then, in the primary transfer portion N1, a toner image on the photosensitive drum 1 is applied to the primary transfer roller 65 by applying a primary transfer bias having a reverse polarity (positive polarity in this embodiment) to the toner during development. Transfer (primary transfer) is performed on the intermediate transfer belt 61 rotating in the direction of arrow A. For example, when forming a full-color image, toner images are sequentially transferred from the photosensitive drums 1Y, 1M, 1C, and 1K to the intermediate transfer belt 61, and conveyed to the secondary transfer unit N2 in a state where the four color toner images are overlapped. Is done.

  The feeding / conveying device 13 includes a supply roller 9 that feeds the recording material P from the recording material cassette 11 that stores the recording material P, and a transport roller 10 that transports the sent recording material P. The recording material P conveyed from the feeding / conveying device 13 is conveyed in synchronism with the toner image by the registration roller pair 17 and then guided by the pre-transfer guide portion 15 as a guide means while being transferred to the secondary transfer portion. Transported to N2.

  In the secondary transfer portion N2, the secondary transfer roller 16 is conveyed to the secondary transfer portion N2 by applying a bias having a polarity opposite to that of the toner at the time of development (positive polarity in this embodiment). The toner image on the intermediate transfer belt 61 is transferred (secondary transfer) to the recording material P.

  The recording material P onto which the toner image has been transferred is conveyed to a fixing device 14 as a fixing unit, and is heated and pressed by a fixing roller 141 and a pressure roller 142 to fix the toner image on the surface. The recording material P on which the toner image is fixed is discharged to the discharge tray 21 by the discharge roller pair 20.

  On the other hand, the toner remaining on the surface of the photosensitive drum 1 after the primary transfer process is removed from the photosensitive drum 1 by the cleaning blade in the drum cleaning device 8 and collected in a waste toner container. Further, the toner remaining on the surface of the intermediate transfer belt 61 after the secondary transfer process is removed from the intermediate transfer belt 61 by the belt cleaning device 22 as an intermediate transfer member cleaning unit. The toner removed from the intermediate transfer belt 61 passes through the waste toner conveyance path 23 and is collected in the waste toner collection container 24.

  In this embodiment, the process cartridges 7Y, 7M, 7C, and 7K, the scanner unit 3, the intermediate transfer unit 6, the secondary transfer roller 16, and the like constitute an image forming unit that forms an image on the recording material P. Further, the feeding / conveying device 13, the registration roller pair 17 and the like constitute a conveying unit that conveys the recording material P to the image forming unit.

2. Next, the guide unit 10 before transfer will be described. FIG. 2 is an enlarged cross-sectional view showing a peripheral portion of the secondary transfer portion N2 in the present embodiment.

  In this embodiment, the pre-transfer guide unit 15 as a guide unit that guides the recording material P conveyed by the conveyance unit to the secondary transfer unit N2 includes a front-side conveyance guide 150 as a guide member, and a back-side conveyance guide 155. Have. The recording material P conveyed to the secondary transfer portion N2 by the registration roller pair 17 passes between the front-side conveyance guide 150 and the back-side conveyance guide 155. The front side conveyance guide 150 is disposed on the surface side of the recording material P on the side to which the toner image is transferred in the secondary transfer portion N2 immediately after passing through the front side conveyance guide 150, and the back side conveyance guide 155 is disposed on the opposite side of the recording material P. It is arranged on the surface side. Hereinafter, the front-side conveyance guide described in detail is also simply referred to as a “conveyance guide”.

  In this embodiment, a guide sheet 151 that is a sheet-like guide member (sheet member) is fixed to the conveyance guide 150. As will be described in detail later, the guide sheet 151 is fixed to the conveyance guide 150 so as to protrude downstream from the conveyance guide 150 in the conveyance direction Pth of the recording material P.

  When the recording material P enters the secondary transfer portion N2, the guide sheet 151 formed of a thin sheet member is used to make the recording material P smoothly enter the surface of the intermediate transfer belt 61 with less impact. It is guided to just before the surface of the transfer belt 61. At this time, the guide sheet 151 may be rubbed and charged by the recording material P that is repeatedly conveyed. Then, when the guide sheet 151 is charged, an image defect such as scattering of an image transferred by the secondary transfer portion N2 may occur. In order to reduce the influence of the charging of the guide sheet 151, the guide sheet 151 is made conductive, electrically connected to an engine ground (not shown) through the conveyance guide 150, and the guide sheet 151 is electrically grounded. There is. In this embodiment, as will be described in detail later, the guide sheet 151 is electrically grounded via the conveyance guide 150.

  The conveyance guide 150 is made of a metal as a conductive material in this embodiment. However, the conveyance guide 150 is not limited to being made of metal, and may be made of conductive synthetic resin. Further, the conveyance guide 150 is not limited to being electrically conductive as a whole, and is configured so that the guide sheet 151 fixed by the conductive double-sided tape can be electrically grounded as will be described in detail later. It only has to be done.

  In addition, as the guide sheet 151, a conductive layer is formed on the surface layer of a synthetic resin film by an arbitrary film forming method (such as sputtering), or the synthetic resin film itself has conductivity (conductivity). Sheet member) can be suitably used. For example, a film in which indium tin oxide (ITO) or the like is sputtered on the surface of a polyester film to impart conductivity to the surface layer, a conductive ultra-high molecular weight polyethylene film, or the like can be given (Patent Document 1). The guide sheet 151 may be made of metal such as SUS (stainless steel). In general, the thickness of the guide sheet 151 is preferably about 100 to 150 μm.

3. Next, a method for fixing the guide sheet (second guide member) 151 to the conveyance guide (first guide member) 150 in this embodiment will be described in detail. FIG. 3 is a schematic plan view of the conveyance guide 150 and the guide sheet 151 in this embodiment as viewed in a direction substantially perpendicular to the plane of the recording material P passing through the pre-transfer guide portion 15, and arrows in the plan view It is the typical side view seen in the F and G directions.

  Note that the conveyance direction of the recording material P is also simply referred to as “conveyance direction”, and the direction intersecting (typically substantially orthogonal) with the conveyance direction is also simply referred to as “recording material width direction”. Further, an area through which the recording material P passes in the width direction of the recording material P is also referred to as a “sheet passing area”, and an area that does not pass through is also referred to as a “non-sheet passing area”.

  In this embodiment, as shown in FIG. 3, when viewed in a direction substantially orthogonal to the plane of the recording material P passing through the pre-transfer guide portion 15, the transfer conveyance guide 150 and the guide sheet 151 are in the width direction of the recording material P. It is made into the substantially rectangular shape long. The guide sheet 151 is fixed to the downstream end side in the transport direction Pth of the surface of the transport guide 150 on the side through which the recording material P passes. As described above, a part of the guide sheet 151 protrudes downstream from the downstream end in the transport direction Pth of the transport guide 150.

  In this embodiment, the guide sheet 151 is affixed and fixed to the conveyance guide 150 with a non-conductive double-sided tape 152 and a conductive double-sided tape 153. More specifically, in this embodiment, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are respectively guided at different positions in the width direction of the recording material P so that at least a part thereof overlaps in the transport direction Pth. The sheet 151 is fixed to the conveyance guide 150. In particular, in this embodiment, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are arranged in a substantially straight line in the width direction of the recording material P so that substantially all overlap in the transport direction Pth.

  At this time, the conductive double-sided tape 153 is only at a position outside the length (maximum sheet passing width) Pmax in the same direction of the recording material P that can be used in the image forming apparatus 100 having the maximum length in the width direction. The guide sheet 151 is affixed to the conveyance guide 150 and fixed. In this embodiment, the conductive double-sided tape 153 is disposed in the vicinity of one end of the guide sheet 151 in the width direction of the recording material P. Note that a conductive double-sided tape 153 may be disposed on both ends of the guide sheet 151 in the width direction of the recording material P.

  On the other hand, the non-conductive double-sided tape 152 affixes and fixes the guide sheet 151 to the conveyance guide 150 at least inside the maximum sheet passing width Pmax. The non-conductive double-sided tape 152 does not need to be disposed only at the position inside the maximum sheet passing width Pmax, and extends to the outside from the maximum sheet passing width Pmax on either end side in the width direction of the recording material P. You can do it. In this embodiment, the non-conductive double-sided tape 152 extends to the outside of the maximum sheet passing width Pmax on both ends in the width direction of the recording material P.

  As described above, in this embodiment, the non-conductive double-sided tape 153 includes the recording material P having the maximum length in the width direction among at least the recording material P used in the image forming apparatus 100 in the width direction of the recording material P. The guide sheet 151 is fixed to the conveyance guide 150 inside the passing area. On the other hand, the conductive double-sided tape 153 guides in the width direction of the recording material P outside the region through which the recording material P having the maximum length in the width direction passes among the recording materials P used in the image forming apparatus 100. The sheet 151 is fixed to the conveyance guide 150. In this embodiment, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are integrally continuous, but one of the non-conductive double-sided tape 152 and the conductive double-sided tape 153 can be used as desired. Or both may be divided | segmented into plurality.

  The guide sheet 151 is electrically connected to the conveyance guide 150 by a conductive double-sided tape 153. On the other hand, the non-conductive double-sided tape 152 is non-conductive and has higher adhesive strength (adhesive strength, adhesive strength) than the conductive double-sided tape 153. Accordingly, it is possible to maintain a high adhesive force by the non-conductive double-sided tape 152 in the sheet passing region while ensuring electrical continuity between the guide sheet 151 and the conveyance guide 150. For this reason, even if sliding friction, rush shock, paper dust, or the like occurs with the recording material P, it is possible to prevent the guide sheet 151 from being lifted or peeled off from the conveyance guide 150 throughout the life of the image forming apparatus 100. be able to.

  Since the recording material P repeatedly rubs the guide sheet 151 in the sheet passing area, the guide sheet 151 is transported in particular using the non-conductive double-sided tape 152 having a relatively high adhesive strength (strong) in the sheet passing area. It is important that the guide 150 is firmly fixed. On the other hand, in the non-sheet passing area, the load applied to the fixed portion is smaller than that in the sheet passing area. Therefore, even if the conductive double-sided tape 153 having a relatively low adhesive strength (weak) is used, the guide sheet 151 is sufficiently practical. Can be fixed to the conveyance guide 150.

  In this embodiment, the surface of the conveyance guide 150 to which the guide sheet 151 is attached is flat, but the present invention is not limited to this. As long as it can be attached with a double-sided tape, the surface may be of any shape.

  Here, the conductive double-sided tape (conductive double-sided adhesive tape) 153 is generally a conductive adhesive in which a conductive filler (conductive particles) such as metal powder is mixed on both sides of a conductive substrate such as a metal foil or conductive cloth. It is configured by applying an agent. For example, copper foil, aluminum foil, stainless steel foil, nickel foil or the like is used as the metal foil as the conductive substrate. As the conductive filler, metal powder such as copper, silver and nickel, carbon powder and the like are used. The conductive double-sided tape 153 has a sufficiently low electrical resistance to ensure electrical continuity between the guide sheet 151 and the conveyance guide 150, for example, because the guide sheet 151 is electrically grounded via the conveyance guide 150. That's fine. Conductive double-sided tape suitable for the application is available on the market.

  On the other hand, the non-conductive double-sided tape (non-conductive double-sided pressure-sensitive adhesive tape) 152 is a so-called normal double-sided tape, and the base material and the adhesive do not have conductivity. As the non-conductive double-sided tape 152, one having higher adhesive strength than the conductive double-sided tape 153 is available on the market. In addition, the adhesive strength of the double-sided tape is, for example, measured by a predetermined testing machine and a predetermined condition according to the measurement of 180-degree peeling adhesive strength of the test method of the adhesive tape / adhesive sheet of JIS-Z0237. it can. In the case of a commercially available double-sided tape, the non-conductive double-sided tape 152 having a sufficiently higher adhesive strength than the conductive double-sided tape 153 can be selected based on the nominal value of the peel adhesive strength.

  As described above, according to the present embodiment, it is possible to suppress the occurrence of floating and peeling of the fixing portion while ensuring electrical continuity between the conveyance guide 150 and the guide sheet 151 fixed thereto. More specifically, in this embodiment, the guide sheet 151 is grounded using the conductive double-sided tape 153 in the non-sheet passing area, and the guide is formed using the non-conductive double-sided tape 152 having high adhesive force in the sheet passing area. The fixing support of the sheet 151 is made stronger. As a result, the occurrence of lifting or peeling of the guide sheet 151 from the conveyance guide 150 is strictly suppressed particularly in the sheet passing area, and the guide sheet 151 is grounded by the conductive double-sided tape 153 in the non-sheet passing portion. it can. Therefore, it is possible to maintain a good fixed state of the guide sheet 151 to the conveyance guide 150 over a long period of time and form a good image in which image defects are suppressed.

Example 2
Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the first embodiment. Therefore, elements having the same or corresponding functions and configurations as those of the image forming apparatus according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the arrangement of the non-conductive double-sided tape 152 and the conductive double-sided tape 153 for attaching the guide sheet 151 to the conveyance guide 150 is different from that of the first embodiment.

  In order to reduce the size of the image forming apparatus 100, it may be desired to reduce the size of the recording material P in the width direction. Therefore, it may be desired to shorten the length of the conveyance guide 150 and the guide sheet 151 in the width direction of the recording material P as much as possible with respect to the maximum sheet passing width Pmax.

  For example, in such a case, a non-conductive double-sided tape 152 having a relatively high adhesive force is disposed on the upstream side in the transport direction Pth inside the maximum sheet passing width Pmax, and the conductive double-sided adhesive layer having a relatively low adhesive force is disposed. The tape 153 is disposed downstream. Thereby, even if sliding friction with the recording material P, rush shock, paper dust, or the like occurs, the floating or peeling of the guide sheet 151 from the conveyance guide 150 is suppressed throughout the life of the image forming apparatus 100. can do.

  This is due to the following reason. As shown in FIG. 5, on the downstream side in the transport direction Pth, the guide sheet 151 receives a force on the side pressed against the transport guide 150 when the recording material P passes, and thus is not easily peeled off from the transport guide 150. Become. Therefore, the double-sided tape that fixes the downstream side in the transport direction Pth has no problem even with the conductive double-sided tape 153 having a relatively low adhesive force. On the other hand, on the upstream side in the transport direction Pth, a force is applied to the guide sheet 151 in a direction in which the guide sheet 151 is peeled off from the transport guide 150 by the lever principle. This is because when the recording material P passes, a force from the recording material P is applied to the leading end portion of the guide sheet 151 on the downstream side in the transport direction Pth, with the boundary surface where the support by the transport guide 150 is removed as a fulcrum. Therefore, it is desirable that the double-sided tape that fixes the upstream side in the transport direction Pth is fixed by the non-conductive double-sided tape 152 having a relatively high adhesive force. Note that there is no problem even if the conductive double-sided tape 153 is disposed in the paper region.

  Thus, in this embodiment, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are respectively guide sheets at different positions in the transport direction Pth so that at least a part thereof overlaps in the width direction of the recording material P. 151 is fixed to the conveyance guide 150. In this embodiment, the non-conductive double-sided tape 152 is disposed on the upstream side in the transport direction Pth, and the conductive double-sided tape 153 is disposed on the downstream side in the same direction. In the present embodiment, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 fix the guide sheet 151 to the conveyance guide 150 at least inside the maximum sheet passing width Pmax.

  4A and 4B are a schematic plan view and a side view of the conveyance guide 150 and the guide sheet 151 in the present embodiment. In the example shown in FIG. 4A, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are arranged in two rows in the transport direction Pth so that substantially all overlap in the width direction of the recording material P. On the other hand, in the example of FIG. 4B, the non-conductive double-sided tape 152 and the conductive double-sided tape 153 are arranged such that a part of one end side overlaps in the width direction of the recording material P. In the example shown in FIG. 4B, the non-conductive double-sided tape 152 further conveys the guide sheet 151 at different positions in the width direction of the recording material P so that at least a part thereof overlaps in the conveyance direction Pth. It is fixed to 150. In this case, as shown in FIG. 4B, the portion overlapping the conductive double-sided tape 153 in the transport direction Pth and the portion overlapping in the width direction of the recording material P are more continuously integrated. This is preferable in that the guide sheet 151 can be firmly fixed to the conveyance guide 150. Note that the non-conductive double-sided tape 152 and the conductive double-sided tape 153 do not need to be arranged only at the position inside the maximum sheet passing width Pmax, and as shown in FIGS. 4A and 4B, the recording material P May extend outside the maximum sheet passing width Pmax on either end side in the width direction.

  FIG. 6 is a cross-sectional view of the vicinity of the secondary transfer portion N2 showing a modification of the present embodiment. FIG. 7 is a schematic plan view and side view of the conveyance guide 150 and the guide sheet 151 of this modification.

  In this modification, the conveyance guide 150 is bent at a bent portion Be extending in the width direction of the recording material P, and the guide sheet 151 is bent at the bent portion Be in the conveyance guide 150 so as to straddle the bent portion Be. It is fixed to the convex side surface. And the nonelectroconductive double-sided tape 153 is arrange | positioned in the conveyance direction Pth at least with respect to the bending part Be at an upstream. The conductive double-sided tape 152 is disposed on the downstream side in the transport direction Pth with respect to the bent portion Be. In this embodiment, the non-conductive double-sided tape 152 is also arranged on the downstream side in the transport direction Pth with respect to the bent portion Be. And the nonelectroconductive double-sided tape 152 each arrange | positioned with respect to the bending part Be on the upstream side and the downstream is integrally continued so that the bending part Be may be straddled. Thereby, the guide sheet 151 can be more firmly fixed to the conveyance guide 150.

  That is, the image forming apparatus 100 is configured to reduce the height H from the registration roller pair 17 to the secondary transfer counter roller 63 as shown in FIG. 6 in order to reduce the height of the apparatus main body E. There is a case. For example, in such a case, the conveyance guide 150 may be provided with the bent portion Be, and the guide sheet 151 may be attached thereon. When the conveyance guide 150 has the bent portion Be, the guide sheet 151 is more upstream of the bent portion Be in the conveyance direction Pth than the case where the conveyance guide 150 is flat, due to the elastic force of the guide sheet 151 acting. 150 may be easily peeled off. In such a case, the configuration of this modified example is effective for firmly fixing the guide sheet 151 to the conveyance guide 150 while reducing the size of the conveyance guide 150 and the guide sheet 151 in the width direction of the recording material P. It is.

  As described above, according to the present embodiment, the occurrence of the floating and peeling of the guide sheet 151 that is likely to occur on the upstream side in the transport direction Pth is particularly strictly suppressed. The guide sheet 151 can be grounded by the tape 153. Therefore, it is possible to maintain a good fixed state of the guide sheet 151 to the conveyance guide 150 over a long period of time and form a good image in which image defects are suppressed.

Others While the present invention has been described with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiments, the present invention is applied to the pre-transfer guide unit as the guide unit. However, a sheet-like guide member is used as the sheet-like guide member in the recording material conveyance path in the image forming apparatus. It is possible to apply the same in the case of fixing.

1 Photosensitive drum (first image carrier)
DESCRIPTION OF SYMBOLS 15 Guide part before transfer 16 Secondary transfer roller 61 Intermediate transfer belt (2nd image carrier)
150 Conveying Guide 151 Guide Sheet 152 Non-conductive Double-Sided Tape 153 Conductive Double-Sided Tape N2 Secondary Transfer Section

Claims (14)

In an image forming apparatus comprising: an image forming unit that forms an image on a recording material; a conveying unit that conveys the recording material; and a guide unit that guides the recording material conveyed by the conveying unit.
The guide means includes a first guide member and a second guide member fixed to the first guide member, and the second guide member is not attached to the first guide member. An image forming apparatus fixed by a conductive double-sided tape and a conductive double-sided tape.   The non-conductive double-sided tape and the conductive double-sided tape are respectively provided at the second guide members at different positions in the direction intersecting the recording material conveyance direction so that at least a part thereof overlaps in the recording material conveyance direction. The image forming apparatus according to claim 1, wherein the image forming apparatus is fixed to the first guide member. The non-conductive double-sided tape is at least inside the region through which the recording material having the maximum length in the same direction among the recording materials used in the image forming apparatus passes in the direction intersecting the conveyance direction of the recording material. Fixing a second guide member to the first guide member;
The conductive double-sided tape is located outside the region through which the recording material having the maximum length in the same direction among the recording materials used in the image forming apparatus passes in the direction intersecting the recording material conveyance direction. The image forming apparatus according to claim 2, wherein the guide member is fixed to the first guide member.   The non-conductive double-sided tape and the conductive double-sided tape are respectively provided at the second guide members at different positions in the recording material conveyance direction so that at least a part thereof overlaps in the direction intersecting the recording material conveyance direction. The image forming apparatus according to claim 1, wherein the image forming apparatus is fixed to the first guide member.   5. The image forming apparatus according to claim 4, wherein the non-conductive double-sided tape is disposed on the upstream side in the recording material conveyance direction, and the conductive double-sided tape is disposed on the downstream side in the same direction. .   The non-conductive double-sided tape further includes the second guide member at the different position in the direction intersecting the recording material conveyance direction so that at least a part of the non-conductive double-sided tape overlaps in the recording material conveyance direction. The image forming apparatus according to claim 5, wherein the image forming apparatus is fixed to the image forming apparatus.   The non-conductive double-sided tape arranged to overlap the conductive double-sided tape in a direction crossing the recording material conveyance direction, and the non-conductive double-sided tape arranged to overlap the conductive double-sided tape in the recording material conveyance direction The image forming apparatus according to claim 6, wherein the non-conductive double-sided tape is integrally continuous. The first guide member is bent at a bent portion extending in a direction intersecting with the conveyance direction of the recording material,
The second guide member is fixed to the first guide member so as to straddle the bent portion,
The non-conductive double-sided tape is disposed upstream of at least the bent portion in the recording material conveyance direction, and the conductive double-sided tape is disposed downstream of the bending portion in the recording material conveyance direction. The image forming apparatus according to claim 4, wherein the image forming apparatus is an image forming apparatus.   The non-conductive double-sided tape is further disposed on the downstream side in the recording material conveyance direction with respect to the bent portion, and the non-conductive double-sided tape and the bent portion are disposed on the upstream side with respect to the bent portion. The image forming apparatus according to claim 8, wherein the non-conductive double-sided tape disposed on the downstream side is integrally continuous so as to straddle the bent portion.   The non-conductive double-sided tape and the conductive double-sided tape pass at least the recording material having the maximum length in the same direction among the recording materials used in the image forming apparatus in the direction intersecting the recording material conveyance direction. 10. The image forming apparatus according to claim 4, wherein the second guide member is fixed to the first guide member inside each region. 11.   The image forming unit includes an image carrier that carries a toner image, and a transfer unit that transfers a toner image from the image carrier to a recording material. The guide unit is configured to transfer the toner image by the transfer unit. The image forming apparatus according to claim 1, wherein the recording material is guided to a position at which the toner image is transferred from the recording material to the recording material.   The image forming apparatus according to claim 1, wherein the second guide member is a sheet member.   13. The first guide member according to claim 1, wherein the second guide member is fixed to the first guide member so as to project downstream from the first guide member in the recording material conveyance direction. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the second guide member is electrically grounded via the first guide member.

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