JP5207099B2 - Transfer unit and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a transfer unit and an image forming apparatus including the transfer unit.

  An image forming apparatus using toner is provided with a photosensitive drum as an image carrier on which an electrostatic latent image is formed. Around the photosensitive drum, a charging device that charges the surface of the photosensitive drum to a predetermined potential, an exposure device that irradiates the charged photosensitive drum with exposure light to form an electrostatic latent image, and the photosensitive drum. A developing device that supplies toner to the electrostatic latent image of the toner and forms a toner image, and a transfer that transfers the toner image held on the photosensitive drum to a sheet (recording medium) at a transfer position close to the photosensitive drum Each roller is arranged.

  In addition, a registration roller is provided on the paper conveyance path (paper conveyance path) to temporarily stop the paper and correct the conveyance posture, and send the paper to the transfer position at a predetermined timing. Between the registration roller and the transfer position (upstream in the conveyance direction of the transfer position), for example, a cloth neutralization unit that removes the paper before the toner image transfer is disposed, and further on the downstream side of the transfer position in the conveyance direction. Are respectively provided with neutralizing means for neutralizing the paper after the transfer of the toner image.

  Here, in the related art, the charge eliminating means for discharging the sheet before transfer is directly attached to the apparatus main body so as to face the sheet conveyance path.

Examples of documents describing the static eliminating means include Japanese Patent Application Laid-Open Nos. 2000-305376, 2004-325484, 2004-325485, and 2004-325486.
JP 2000-305376 A JP 2004-325484 A JP 2004-325485 A JP 2004-325486 A

  Here, in the conventional technique as described above, the sheet discharging means before the toner image transfer is directly attached to the main body of the apparatus, so that attachment workability is deteriorated. In particular, in the case where the static eliminating means is a soft member such as cloth, it is more difficult to attach to the regular position in a narrow mounting space, so the mounting position is shifted and the conveyance path is obstructed, so-called paper jam occurs. There is a fear.

  In addition, since the mounting workability is poor as described above, it is difficult to replace it with a new one at the user's stage even if the static elimination means deteriorates due to the use of the image forming apparatus, and it is necessary to rely on a professional engineer. Absent.

  An object of this invention is to provide the technique which can improve the attachment workability | operativity of a static elimination means.

  Another object of the present invention is to provide a technique that can easily replace the static eliminating means.

In order to solve the above problems, the transfer unit of the present invention according to claim 1 is disposed opposite to an image carrier, and a transfer unit that transfers a toner image formed on the image carrier to a recording medium; A base member to which the transfer unit is attached and is removed by moving in a direction crossing the transport path of the recording medium and moving away from the transport path with respect to the apparatus main body, and mounted by moving in a direction opposite to the direction. When made fabric member having conductivity, so the other end opposite to the tip the conveyance path side to the distal end outer surface of the transport path extending toward the pair of registration rollers in the base member away from said recording medium A neutralizing unit that neutralizes the recording medium before the toner image is transferred, and is attached to the base member in contact with the neutralizing unit; And a conductive plate made of a metal that is a potential, said charge removing means is a ground potential through the conductive plate, it is characterized.

According to a second aspect of the present invention, in the first aspect of the present invention, the base member is provided with a mounting recess to which the static elimination means is attached, and the static elimination means is attached to the mounting concave portion. To do.

According to a third aspect of the present invention, in the second aspect of the present invention, a lightening space is formed on the back side of the mounting recess.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects of the present invention, the conveyance path is located at a position on the conveyance path side from the conveyance path side mounting end of the base member in the static elimination means. A notch extending toward is formed.

According to a fifth aspect of the present invention, in the invention of the fourth aspect , the notch is formed over the entire area in the longitudinal direction of the static elimination means.

The image forming apparatus of the present invention according to claim 6, characterized in that a transfer unit according to any one of claims 1 to 5.

  According to the first aspect of the present invention, since the transfer unit can be detached from the apparatus main body and the static eliminator can be attached to the outer surface of the base member, the workability when the static eliminator is attached is improved. Therefore, there is no possibility that the static eliminating unit is displaced from the normal mounting position and obstructs the conveyance path of the recording medium, and so-called paper jam occurs frequently in the static eliminating unit.

  According to the first aspect of the present invention, since the static eliminator can be replaced integrally with the transfer unit, for example, when there is a need to replace the static eliminator due to deterioration or the like, the transfer means is replaced due to deterioration of the transfer means. Even when the transfer unit is replaced for a reason such as when it is used, the user can easily replace it with a new one without relying on a specialized engineer.

  According to the second aspect of the present invention, the recording medium is in contact with the static eliminator as compared with the case where the static eliminator is disposed in parallel with the conveyance path and the recording medium comes into contact with the attachment portion of the static eliminator. In this case, it is possible to prevent the occurrence of a so-called paper jam because the transport path is not removed or the transport is not hindered.

  According to the third aspect of the present invention, since the discharge of the recording medium is performed in the vicinity of the nip portion of the registration roller, the conveyance path is independent of the type and conveyance posture of the recording medium or the strength of the recording medium. It is possible to reliably perform static elimination on the recording medium conveyed. Further, even when the neutralizing unit is brought into contact with the recording medium as required, the tip of the recording medium can be reliably brought into contact with the neutralizing unit.

  According to the fourth aspect of the present invention, since the static eliminator is positioned and attached, the static eliminator can be securely attached at a correct position.

  According to the fifth aspect of the present invention, even if the base member is made of resin and contracts during the molding process, deformation is relieved in the mounting recess whose thickness is reduced due to the thinning space. The positional accuracy of the static elimination means attached to the attachment recess is increased. Thereby, peeling of the static elimination means and paper jams due to interference of the static elimination means are prevented.

  According to the sixth aspect of the present invention, even if the recording medium comes into contact with the static eliminator, the recording medium is transported while being rolled over the static eliminator, so that a paper jam due to the interference of the static eliminator does not occur.

  According to the seventh aspect of the present invention, it is possible to prevent the tip corner portion of the recording medium from being caught by the charge eliminating means regardless of the size of the recording medium.

  According to the eighth aspect of the present invention, an image forming apparatus can be obtained in which the workability of attaching the charge removal means is good and the charge removal means can be easily replaced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  1 and 2, the image forming apparatus 12 includes an apparatus main body 14 including a chute 52 (FIGS. 3 and 7 to 10), and a transfer roller unit (transfer unit) 54 that is detachably attached to the chute 52. And have. The apparatus main body 14 has one or a plurality of (four in the case shown in FIGS. 1 and 2) paper feed cassettes 16. The sheets (recording media) accommodated in the respective sheet feeding cassettes 16 are taken out one by one by a nudger roller 18 and sent into the conveyance path 20. A retarder roller 22 and a feed roller 24 are sequentially provided in the transport path 20, and the paper is rolled by these rollers 22 and 24 and transported on the transport path 20.

  A pair of registration rollers 26 is provided on the downstream side of the retard roller 22 and the feed roller 24 in the paper conveyance direction, and the paper is temporarily stopped by the registration rollers 26 to correct the conveyance timing and posture.

  A process cartridge 28 is disposed in the apparatus main body 14, and a photosensitive drum (image holding member) 30, a charging device 32, a developing device 34, and a cleaning device 36 are accommodated and integrated in the process cartridge 28. Yes.

  Here, when the surface of the photosensitive drum 30 is uniformly charged to a predetermined potential by the charging device 32 and the surface of the photosensitive drum 30 is irradiated with the light beam from the optical scanning device 38 in a charged state, the portion thereof is obtained. The charging potential of the latent image decreases and a latent image (electrostatic latent image) is formed. Then, a toner image is formed on the photosensitive drum 30 by the toner adhering to the latent image by the developing device 34.

  The photosensitive drum 30 and the transfer roller unit 54 are disposed on the downstream side of the registration roller 26 in the sheet conveyance direction. As shown in the figure, the transfer roller unit 54 has a transfer roller (transfer means) 56, and the toner on the photoconductive drum 30 is conveyed while the paper is nipped between the photoconductive drum 30 and the transfer roller 56. Transfer the image to the paper.

  As shown in FIG. 2, the process cartridge 28 is integrally moved from the apparatus main body 14 and reaches a retracted position (not shown). By this movement, the photosensitive drum 30 is separated from the transfer roller 56, and a work space S for exchanging a transfer roller unit 54 described later is formed in the image forming apparatus 12.

  A fixing device 40 is disposed downstream of the photosensitive drum 30 and the transfer roller unit 54 in the sheet conveyance direction. The fixing device 40 includes, for example, a heating roller 42 and a pressure roller 44, and the toner image on the sheet is fixed by conveying the sheet while heating and pressing the sheet with these rollers 42 and 44.

  A discharge roller 46 is disposed on the downstream side of the fixing device 40 in the sheet conveyance direction. The sheet on which the toner image is fixed in the fixing device 40 is nipped and conveyed by the discharge roller 46 and is discharged from the discharge port 48 to the discharge tray 50.

  As shown in detail in FIGS. 3 to 10, the transfer roller unit 54 includes a long base member 58 and a transfer member housed in a housing portion 60 of the base member 58 and rotatably attached to the base member 58. And a roller 56. The transfer roller 56 is formed into a cylindrical shape using, for example, foamed resin, and a part thereof (a portion facing the photosensitive drum 30) is exposed from the base member 58 while being accommodated in the accommodating portion 60.

  A shaft 62 is inserted through the center of the transfer roller 56, and both ends of the shaft 62 are an end portion 62 </ b> A and the other end portion 62 </ b> B exposed from the transfer roller 56. The one end portion 62A and the other end portion 62B are respectively connected to the base member 58 via a bearing 64 fitted in the base member 58 and a pressure coil spring (not shown) that biases the shaft 62 away from the base member 58. Is rotatably supported. Since the pressure coil spring urges the shaft 62 in the direction away from the base member 58 as described above, the transfer roller 56 is caused to move the photosensitive drum 30 by the urging force when the shaft 62 is attached to the apparatus main body 14. Pressed against.

  At one end 62A of the shaft 62, a tracking roll 70 is disposed outside the bearing 64, and a drive gear 72 is disposed outside the tracking roll 70.

  The tracking roll 70 is formed in a ring shape, and its inner diameter is determined so as to be coaxial with the shaft 62 and relatively rotatable without shaking in the radial direction. Further, the outer diameter of the tracking roll 70 is set so that the outer peripheral surface of the tracking roll 70 is in contact with the outer peripheral surface of the photosensitive drum 30 in a state where the tracking roller 70 is mounted, and the distance between the transfer roller 56 and the photosensitive drum 30 is set. It is decided to keep it constant.

  The drive gear 72 rotates integrally with the shaft 62, and receives a driving force from a driving source (not shown) to rotate the shaft 62 and the transfer roller 56 at a predetermined angular velocity.

  Only the tracking roll 70 is disposed at the other end portion 62 </ b> B of the shaft 62.

  As shown in FIGS. 5 to 10, two positioning convex members 92 are provided on the side of the base member 58 where the transfer roller 56 is not exposed, that is, on the opposite side of the photosensitive drum 30 across the transfer roller 56. It has been. The positioning convex member 92 can be inserted into a positioning hole 94 of the chute 52 formed correspondingly.

  As shown in FIG. 7, the positioning convex member 92 includes a nip portion P1 between the transfer roller 56 that rotates in the W1 direction and the photosensitive drum 30 that rotates in the W2 direction as viewed from the longitudinal direction of the rotation axis of the shaft 62. , And is formed in a convex shape on a straight extension line E passing through the rotation center O of the shaft 62. As shown in FIG. 6, the positioning convex member 92 is wide in the longitudinal direction of the rotational axis of the shaft 62 (can resist the force applied from the rotational direction of the transfer roller 56 in the longitudinal direction of the rotational shaft. Wide). As a result, the strength can be increased with respect to the rotational force applied by the rotation of the transfer roller 56. Further, the tip of the positioning convex member 92 is tapered over the length L2 so that it can be easily inserted into the positioning hole 94.

  The chute 52 is fixed to the apparatus main body 14. The chute 52 is provided with a mounting space 52S in which the transfer roller unit 54 can be accommodated. A positioning hole 94 into which the positioning convex member 92 can be inserted is formed at a position corresponding to the positioning convex member 92 on the back side of the mounting space 52S. Restricting members 95 are provided on both sides of the positioning hole 94. The restriction member 95 is provided with two in total, one on the upper side of the positioning hole 94 and one on the lower side, so that the positioning convex member 92 can be inserted into the positioning hole 94 and the insertion direction of the positioning convex member 92 is It protrudes toward the inside of the positioning hole 94 to such an extent that the movement in the direction orthogonal to is regulated.

  As shown in FIG. 9, the length L1 in the insertion direction of the positioning convex member 92 into the chute 52 (hereinafter referred to as “X direction”) is a guide portion 98 that is curvedly formed on the mounting side of the transfer roller unit 54 in the chute 52. The length H is substantially the same as the length H from the front end portion 98A to the front end portion of the regulating member 95.

  As shown in the drawing, the tip end portion 98 </ b> A of the guide portion 98 is located closest to the positioning convex member 92 of the chute 52. Therefore, when the positioning convex member 92 is inserted into the positioning hole 94, members other than the positioning convex member 92 of the transfer roller unit 54 do not easily hit the chute 52, so that the positioning convex member 92 is easily inserted into the positioning hole 94.

  The chute 52 is provided with notch recesses (not shown) that fit into mounting pins 88 (FIGS. 6, 9, and 10) formed on lever members 74 and 76 provided at both ends of the transfer roller unit 54. It has been. Details of this will be described later.

  Further, as shown in detail in FIGS. 4 to 10, the base member 58 has a neutralizing plate 96 and a neutralizing cloth (static neutralizing means) 97 for neutralizing the sheet with the transfer roller unit 54 mounted on the apparatus main body 14. It is attached.

  The neutralization plate 96 is a plate-like body that is attached to the upper outer surface of the base member 58 and is made of a conductive metal such as stainless steel and is provided over the entire sheet conveyance width. The side of the static elimination plate 96 on the side of the conveyance path 20 is subjected to a bending process in which a number of fins extending along the sheet conveyance direction are formed at regular intervals. A bias voltage having a polarity opposite to that of the transfer roller 56 is applied to the neutralizing plate 96 by a high voltage power source (not shown). Then, as described above, the transfer roller 56 discharges the sheet on which the toner image has been transferred from the photosensitive drum 30 in a non-contact state to remove the charge, thereby preventing the sheet from being wound around the photosensitive drum 30.

  The neutralizing cloth 97 is attached to the outer surface on the opposite side of the neutralizing plate 96 with the transfer roller 56 interposed therebetween, and is provided over the entire sheet conveying width. For example, a conductive cloth in which a copper wire thread is woven into a polyester fabric. It is a shaped member.

  Here, the base member 58 includes a first portion 58-1 facing the conveyance path 20 over a substantially sheet conveyance width in a state where the transfer roller unit 54 is mounted on the apparatus main body 14, and the first portion 58-1. It has the 2nd site | part 58-2 formed at a predetermined angle with respect to this 1st site | part 58-1 in a lower end. As shown in FIG. 5, a mounting recess 58-2a is formed on the outer surface of the second portion 58-2, and the neutralizing cloth 97 described above is fitted into the mounting recess 58-2a on one side in the width direction. The other side is attached to the second portion 58-2 in a state of protruding from the attachment recess 58-2a to the conveyance path 20 side. And since the static elimination cloth 97 is positioned and attached by the mounting recess 58-2a in this way, the static elimination cloth 97 is securely attached at the correct position.

  A lightening space 77 is formed on the back side of the mounting recess 58-2a. Thus, even if the resin base member 58 contracts during the molding process, the deformation is reduced in the mounting recess 58-2a having a reduced thickness due to the thinning space 77, so the mounting recess 58-2a. The positional accuracy of the neutralizing cloth 97 attached to the is increased. Thereby, peeling of the static elimination means and paper jams due to interference of the static elimination means are prevented. However, the base member 58 does not have to be made of resin, and even if it is made of resin, the lightening space 77 may not be formed.

  A metal conductive plate 99 having a ground potential is attached to the first portion 58-1. The conductive plate 99 is in contact with the neutralizing cloth 97, and therefore the neutralizing cloth 97 is dropped to the ground potential via the conductive plate 99. Such a neutralizing cloth 97 comes into contact with the sheet before the toner image from the photosensitive drum 30 is transferred to eliminate the static electricity, and removes static electricity generated during conveyance by the registration roller 26 or the like.

  As shown in FIGS. 7 and 8, the neutralizing cloth 97 is arranged so as to intersect the conveyance path 20 in a state where the transfer roller unit 54 is mounted on the apparatus main body 14. If the neutralizing cloth 97 is in parallel with the conveyance path 20, the paper may come into contact with the neutralizing cloth 97 and come off the conveyance path 20 or the conveyance may be hindered. However, the sheet is arranged so as to intersect the conveyance path 20. If this is the case, such a fear is eliminated and the occurrence of a so-called paper jam is prevented. Note that, as in the present embodiment, when the conveyance path 20 side hangs down by its own weight as in the case of the neutralizing cloth 97 (the static eliminator is a cloth-like member), the drooping portion only needs to intersect the conveyance path 20.

  Further, as shown in FIG. 7, in the state where the transfer roller unit 54 is mounted on the apparatus main body 14, the charge removal cloth 97 has a sheet discharge position P <b> 2 by the charge removal cloth 97 at the toner image transfer position by the transfer roller 56. The nip portion P1 is positioned closer to the nip portion P3 of the pair of registration rollers 26 than the nip portion P1.

  With such a positional relationship, the sheet is neutralized in the vicinity of the nip portion P3 of the registration roller 26. Therefore, regardless of the type of sheet, the conveyance posture, or the strength of the sheet, the conveyance path The neutralization is surely performed on the sheet 20 being conveyed. Further, since the leading edge of the sheet can be reliably brought into contact with the neutralizing cloth 97, it is possible to stably neutralize the sheet.

  A cutout 97 a extending toward the conveyance path 20 is formed over the entire area in the longitudinal direction of the neutralization cloth 97 at a position on the conveyance path 20 side from the attachment end on the conveyance path 20 side of the base member 58 in the static elimination cloth 97. Even if the sheet to be conveyed comes into contact with the neutralizing cloth 97, the sheet is conveyed while being wiped through the neutralizing cloth 97, so that the contact neutralizing type neutralizing cloth 97 interferes with the sheet and the paper is conveyed. No clogging occurs. Further, since the notch 97a extends over the entire area of the neutralizing cloth 97 in the longitudinal direction, the leading edge portion of the sheet is prevented from being caught by the neutralizing cloth 97 regardless of the size of the sheet.

  Note that the neutralizing cloth 97, which is a neutralizing means in this embodiment, is a contact neutralizing type that neutralizes by contacting the paper as a ground potential, but a bias voltage having a polarity opposite to the charging potential of the paper is applied. A non-contact static elimination type that discharges electricity without contact with the paper may be used. Further, in the present invention, various electrically conductive members such as a metal brush can be used as the charge eliminating means before transferring the toner image, and are not limited to those made of cloth as shown in this embodiment. Absent.

  As shown in FIGS. 3 to 6, lever members 74 and 76 are attached to both ends of the base member 58, respectively. The lever member 74 on one end side has a holder portion 78 that fits with the base member 58 and covers the central axis of the drive gear 72, and in the state of fitting with the base member 58, the shaft is inserted through the drive gear 72. While being prevented from coming off from the base member 58 on the one end portion 62A side of 62, it can be moved within a predetermined range.

  Similarly, the lever member 76 on the other end side has a holder portion 80 that fits with the base member 58 and covers the vicinity of the other end portion 62 </ b> B of the shaft 62. It is possible to move within a predetermined range while preventing the other end portion 62B from coming off from the base member 58.

  As described above, since the lever 62 and 76 prevent the shaft 62 from coming off, for example, even when the transfer roller unit 54 is being transported, the shaft 62 and the transfer roller 56 are not accidentally dropped. Absent.

  When the lever members 74 and 76 are attached to the base member 58, the drive gear 72, the tracking roll 70, the shaft 62, and the transfer roller 56 are integrated (unitized) with the base member 58, and the transfer roller unit 54. Is configured.

  The lever members 74 and 76 have lever portions 82 and 84 formed above and below the holder portions 78 and 80, respectively. These lever portions 82 and 84 are also vertically attached when mounted on the apparatus main body 14. And located on the work space S side (see FIG. 2).

  The upper lever portion 82 is formed in a substantially J-shaped cross section, and the middle portion is an elastic portion 86 that exhibits predetermined elasticity. Then, the elastic portion 86 is elastically deformed, whereby the tip end portion 82T of the lever portion 82 moves to the lever portion 84 side. The lower lever portion 84 extends gradually away from the distal end portion 82T of the upper lever portion 82, and grips the vicinity of the distal end portion 82T of the lever portion 82 and the lever portion 84. Thus, the lever portion 82 can be bent.

  The lever 82 is provided with the above-described mounting pin 88 projecting along the axial direction of the shaft 62, and the position of the lever portion 82 in a state where the elastic portion 86 is not bent as the lever portion 82 moves. It moves between the (fit position) and the position in the bent state (fit release position).

  At the fitting position, the mounting pin 88 is fitted into a notch recess formed in the chute 52 so that the base member 58 is attached to the chute 52 constituting a part of the apparatus main body 14, and the transfer roller unit 54 from the chute 52 is attached. Inadvertent withdrawal is prevented. At this time, the mounting pin 88 receives the elastic force from the elastic portion 86 and is in pressure contact with a part of the notch recess. When the upper lever portion 82 is bent and the mounting pin 88 is fitted and moved to the release position, the base member 58 can be detached from the chute 52 and the transfer roller unit 54 can be removed from the chute 52.

  In such a configuration, with the transfer roller unit 54 removed from the apparatus main body 14, the base member 58 (in this embodiment, the second portion 58-2 of the base member 58 is included in the transfer roller unit 54. The neutralizing cloth 97 is attached to the attachment recess 58-2a) formed on the outer surface. When the neutralizing cloth 97 is directly attached to the apparatus main body 14, the attachment workability is poor. In particular, in the case of a soft member such as a cloth as in the present embodiment, it is difficult to attach it to a normal position in a narrow attachment space. It is. However, since the neutralizing cloth 97 is attached to the outer surface of the base member 58 of the transfer roller unit 54 removed from the apparatus main body 14, the attachment workability is improved. Therefore, there is no case where the neutralizing cloth 97 is displaced from the normal mounting position and obstructs the paper conveyance path 20 to cause a so-called paper jam.

  When the transfer roller unit 54 is mounted on the apparatus main body 14, the operator holds the lever portions 82, 84 and flexes the upper lever portion 82 while holding the positioning convex member 92 of the transfer roller unit 54. Insert into the corresponding positioning hole 94. Then, when the lever portions 82 and 84 are released, the mounting pin 88 is fitted into the cutout recess, and the storage of the transfer roller unit 54 in the mounting space 52S is completed. After the transfer roller unit 54 is mounted on the apparatus main body 14 in this way, the photosensitive drum 30 comes into contact with the transfer roller 56 when the process cartridge 28 is returned to a predetermined position as shown in FIG.

  When removing the used transfer roller unit 54 from the apparatus main body 14, first, as shown in FIG. 2, the process cartridge 28 is moved to a retracted position (not shown). As a result, the photosensitive drum 30 is separated from the transfer roller 56, and a work space S for replacing the transfer roller unit 54 is formed in the apparatus main body 14.

  Next, the lever portions 82 and 84 are gripped from the work space S side, the upper lever 82 is bent, and the mounting pin 88 is moved to the fitting release position. In this state, when the lever portions 82 and 84 are pulled out to the front side, the transfer roller unit 54 is removed from the chute 52 of the apparatus main body 14. Then, a new transfer roller unit 54 is mounted on the apparatus main body 14 in the manner described above.

  If the transfer roller unit 54 is replaced in this way, the neutralizing cloth 97 is replaced with the transfer roller unit 54. Therefore, even when it is necessary to replace the neutralizing cloth 97 due to deterioration or the like, The user can easily replace it with a new one without relying on a specialized engineer.

  In the above description, the present invention is applied to a monochrome laser printer. However, the present invention can also be applied to a color printer. In the above description, a photosensitive drum is used as the image carrier. However, the toner image formed on the photosensitive drum is once transferred to a belt (transfer belt) and then transferred to a recording medium by a transfer roller. In such an image forming apparatus, a transfer belt is applied as the image carrier.

1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention with a process cartridge retracted. 1 is a perspective view showing a transfer unit mounted on an image forming apparatus according to an embodiment of the present invention together with a chute constituting an apparatus main body. It is a perspective view which shows the transfer unit which is one embodiment of this invention. FIG. 5 is an exploded perspective view showing a transfer unit according to an embodiment of the present invention rotated about 90 ° counterclockwise from the position shown in FIG. 4. FIG. 5 is a perspective view showing a transfer unit according to an embodiment of the present invention rotated about 90 ° clockwise from the position shown in FIG. 4. It is sectional drawing which shows the state which mounted | wore the chute | shoot with the transfer unit which is one embodiment of this invention from the shaft direction with the peripheral component of a transfer unit. It is sectional drawing which shows the state which mounted | wore the chute | shoot with the transfer unit which is one embodiment of this invention from a shaft direction. It is sectional drawing which shows the state which removed the transfer unit which is one embodiment of this invention from the chute | shoot from a shaft direction. It is sectional drawing which shows the state in the middle of mounting | wearing the chute | shoot with the transfer unit which is one embodiment of this invention from a shaft direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Image forming apparatus 14 Apparatus main body 20 Conveyance path 26 Registration roller 30 Photosensitive drum (Image holding body)
52 Chute 54 Transfer roller unit (transfer unit)
56 Transfer roller (transfer means)
58 Base member 58-1 First part 58-2 Second part 58-2a Mounting recess 77 Meat removal space 96 Static elimination plate 97 Static elimination cloth (static elimination means)
97a Notch 98 Guide part 99 Conductive plate P1 Nip part P2 Static elimination position P3 Nip part

Claims (6)

A transfer unit disposed opposite to the image carrier and transferring a toner image formed on the image carrier to a recording medium;
The transfer unit is attached and the base is attached to the apparatus main body by being moved in a direction crossing the conveyance path of the recording medium and moving away from the conveyance path, and moved in a direction opposite to the direction. Members,
Consists fabric member having conductivity, mounted so as the other end opposite to the tip the conveyance path side to the distal end outer surface of the transport path extending toward the pair of registration rollers is separated from the recording medium in said base member Neutralizing means for neutralizing the recording medium before the toner image is transferred;
A metal conductive plate attached to the base member in contact with the static elimination means and having a ground potential;
The static elimination means is at a ground potential through the conductive plate,
A transfer unit characterized by that. The base member is formed with a mounting recess to which the static elimination means is mounted.
The transfer unit according to claim 1, wherein the static elimination unit is attached to the attachment recess. The transfer unit according to claim 2, wherein a lightening space is formed on the back side of the mounting recess. The incision extended toward the said conveyance path is formed in the location by the side of the said conveyance path from the conveyance path side attachment end of the said base member in the said static elimination means. The transcription unit described. The transfer unit according to claim 4, wherein the cut is formed over the entire area in the longitudinal direction of the charge eliminating unit.   An image forming apparatus comprising the transfer unit according to claim 1.

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