JP2001206588A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing a toner depositing on a feed guide plate from adhering to the rear surface of a transfer medium, and allowing simple grounding of the feed guide plate. SOLUTION: After a transferring part 5c transfers a toner image to a sheet S, the sheet S is delivered to a fixing part 8 by a feeding means 12 disposed between the fixing and transferring parts 8 and 5c. The feeding means 12 has a guide member 12c provided with a plurality of ribs 12r and with a feed guide plate 41 formed from a conductor and placed between the ribs. The feed guide plate 41 is grounded. The height of the ribs 12r is set not to cause the sheet S to electrostatically attract toner depositing on the feed guide plate 41, when feeding the sheet S. The feeding means 12 is integrally provided with the guide member 12c and mounted releasably on a device body. The feed guide plate 41 is grounded upon mounting the feeding means 12 on the device body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly, to a structure of a conveying unit for conveying a sheet on which a toner image has been transferred to a fixing unit.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, and a facsimile using an electrophotographic system, a toner image formed by developing a latent image on an image carrier is transferred to a sheet by a transfer unit. Then, the toner image is fixed on a sheet by a fixing unit.

FIG. 8 is a diagram showing a schematic configuration of a black-and-white laser printer (LBP) which is an example of such an image forming apparatus. In this laser printer, a half-moon-shaped pickup roller 67e is provided from a cassette tray 67a.
The transfer material S sent out by the feed roller 67f
Are separated one by one by a retard roller 67g and a registration roller pair 67d via a conveying roller pair 67b.
Is to be reached.

Thereafter, the transfer material S is conveyed by a pair of registration rollers 67d in accordance with the rotation of a photosensitive drum 61 as an electrophotographic photosensitive member disposed in a process cartridge B1 serving as a recording means. 65 allows the toner image on the photosensitive drum 61 to be transferred.

The transfer material S onto which the toner image has been transferred as described above passes through a nip portion between the photosensitive drum 61 and the transfer roller 65, and then is transferred to the transfer guide unit 72.
Downward transport belt 72a, transport guide rib 72b
Then, the toner is conveyed to the nip portion between the heating roller 68b and the pressure roller 68a along the fixing entrance guide 68c.

[0006] Then, the transfer material S is
b, the toner image on the transfer material S is fixed as a permanent image by being heated and pressed when passing through the nip portion of the pressure roller 68a, and then along the conveyance guide rib 75 via the paper discharge roller pair 73. Is transported, and the discharge roller pair 69
As a result, the sheet is discharged and stacked on the face down tray 70 at the upper part of the apparatus main body.

The transport guide unit 72 has a configuration in which a mold member having several transport guide ribs 72b is covered with a transport guide plate 72c made of sheet metal.
Further, the transport guide plate 72c is dropped on the ground of the apparatus main body. Since the transfer material S transported from the transfer unit is charged, the transfer material S is transported while being electrostatically attracted to the transport guide plate 72c by grounding the transport guide plate 72c in this manner. It is going to go.

[0008]

However, in such a conventional image forming apparatus, the height h of the transport guide rib 72b of the transport guide unit 72 shown in FIG. 1 is about 0.5 to 2 mm from the height of the transport guide plate 72c. When the scattered toner, paper dust and the like accumulate on the surface of the transport guide plate due to long-term use, the scattered toner, paper dust and the like are transported to the transport guide unit 72 by the transfer material S.
Adhered to the back surface of the substrate, causing back-surface dirt. This is a particular problem in a rotary full-color LBP using developing devices of four colors of Y, M, C, and Bk.

Further, in the conventional image forming apparatus having such a configuration that the transport guide plate 72c is grounded, there is a problem that it takes time and effort to ground the transport guide plate 72c.

The present invention has been made in view of such circumstances, and provides an image forming apparatus capable of preventing toner accumulated on a conveyance guide plate from adhering to the back surface of a transfer material. Is a first object.
It is a second object of the present invention to provide an image forming apparatus capable of easily grounding a transport guide plate.

[0011]

According to the present invention, a toner image formed by developing a latent image on an image carrier is transferred to a sheet by a transfer unit and then fixed to the sheet by a fixing unit. In the image forming apparatus, a conveyance unit provided between the fixing unit and the transfer unit, and configured to convey the sheet on which the toner image has been transferred to the fixing unit; A guide member provided with a plurality of ribs formed and on which the sheet slides, and a transport guide plate provided between the ribs and formed of a conductor; and a transport guide plate of the guide member. And the height of the ribs of the guide member is set to a height at which the sheet does not electrostatically attract toner accumulated on the conveyance guide plate when the sheet is conveyed. Features It is intended.

Further, according to the present invention, the transfer means integrally includes the guide member and is detachably provided on the apparatus main body, and the transfer guide plate is grounded when the transfer means is mounted on the apparatus main body. It is characterized in that the

Further, as in the present invention, after a toner image formed by developing a latent image on an image carrier is transferred to a sheet by a transfer unit, a conveying unit provided between the fixing unit and the transfer unit To the fixing unit. In addition, a guide member including a plurality of ribs formed of an insulator and on which a sheet slides, and a conveyance guide plate provided between the ribs and formed of a conductor is provided on the conveying means. The conveyance guide plate of the guide member is grounded, and the height of the rib of the guide member is adjusted so that the sheet does not electrostatically adsorb the toner deposited on the conveyance guide plate when the sheet is conveyed. Height. Further, a guide member is integrally provided in the transporting means, and the transporting means is detachably provided in the apparatus main body, and the transport guide plate is grounded as the transporting means is mounted on the apparatus main body.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a four-color full-color laser beam printer which is an example of an image forming apparatus according to an embodiment of the present invention.

In FIG. 1, reference numeral 100 denotes a laser beam printer (hereinafter, referred to as LBP).
Reference numeral 0 includes a drum-type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) 1 as a first image carrier.

Here, the photosensitive drum 1 is driven to rotate counterclockwise in FIG. 1 by a driving means (not shown). A charging device 2 for uniformly charging the surface of the photosensitive drum 1 in order according to the direction; an exposure unit 3 for irradiating a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1; A developing device 4 for attaching toner to the upper electrostatic latent image to develop it as a toner image; an intermediate transfer unit 5 for primary transfer of the toner image on the photosensitive drum 1; a surface of the photosensitive drum 1 after primary transfer A cleaning device 6 for removing the post-transfer toner remaining in the printer is provided.

In the present embodiment, the photosensitive drum 1, the charging device 2, and the cleaning device 6 are integrally formed as a cartridge, and the device main body 1 of the LBP 100 is provided.
4, a detachable process cartridge B is formed.

In the present embodiment, the photosensitive drum 1 is formed by applying an organic photoconductor layer (OPC photosensitive member) to an outer peripheral surface of, for example, an aluminum cylinder having a diameter of 47 mm. The photosensitive drum 1 is rotatably supported at both ends by support members.
The driving force from a driving motor (not shown) is transmitted to one end, so that the driving unit is rotated in the direction of the arrow.

On the other hand, the charging device 2 is disclosed in, for example,
This is a so-called contact charging system as disclosed in JP-A-149669, in which a conductive roller 2a is used as a charging member, and the conductive roller 2a is brought into contact with the surface of the photosensitive drum 1 and the conductive roller 2a is By applying a charging bias voltage from a power supply (not shown),
The surface of the photosensitive drum 1 is uniformly charged.

The exposure means 3 includes a laser diode (not shown), a polygon mirror 3a rotated at high speed by a scanner motor (not shown), an imaging lens 3b, a reflection mirror 3c, and the like. The laser diode irradiates image light corresponding to the image signal to the polygon mirror 3a rotating at high speed, reflects the image light by the polygon mirror 3a, and further reflects the reflected image light on the imaging lens 3b. By irradiating the charged photosensitive drum 1 via the reflection mirror 3c and the like, the surface of the photosensitive drum 1 is selectively exposed to form an electrostatic latent image.

The developing device 4 has a rotating body 4A which can be indexed and rotated about a shaft 4d, and four rotating bodies 4A, which are individually detachably mounted on the rotating body 4A, namely, yellow, magenta, cyan and black. Developing device 4 containing toner of each color
Y, 4M, 4C, and 4Bk, and developing units 4Y, 4M, 4C, and 4Bk of colors to be attached to the electrostatic latent image by indexing rotation of the rotating body 4A during development of the electrostatic latent image are arranged at the developing position. I am trying to do it.

The predetermined developing units 4Y and 4Y
When M, 4C, and 4Bk stop at the developing position facing the photosensitive drum 1, the developing sleeves 4b of the developing devices 4Y, 4M, 4C, and 4Bk are connected to a high-voltage power supply (not shown) for each color provided on the apparatus main body 14. Connected. Then, thereafter, the developing sleeve 4b is moved from the photosensitive drum 1 by a minute gap (30
(About 0 μm), and the electrostatic latent image on the photosensitive drum 1 is developed thereafter.

Here, when developing the electrostatic latent image, first, the toner in the container of the developing device corresponding to the color to be developed is fed to the coating roller 4a by a feeding mechanism (not shown), and the rotating coating roller 4a is rotated. In addition, the toner regulating blade 4c applies a thin layer of toner to the outer periphery of the rotating developing sleeve 4b, and applies a charge to the toner (friction charging). Next, a developing bias is applied between the developing sleeve 4b and the photosensitive drum 1 on which the electrostatic latent image is formed for each color development, whereby toner is attached to the electrostatic latent image to form a toner image. develop.

The intermediate transfer unit 5 includes an intermediate transfer belt 5a for secondary-transferring a plurality of toner images sequentially primary-transferred from the photosensitive drum 1 and superimposed on the transfer material S collectively, and an intermediate transfer belt 5a. Transfer material S on toner image on belt 5a
And a secondary transfer roller 5n for collectively transferring the images to the printer.

Here, the intermediate transfer belt 5a is a belt having a circumference of about 440 mm, and is stretched over three rollers of a driving roller 5b, a secondary transfer opposing roller 5c, and a driven roller 5d, and rotates the driving roller 5b. As a result, the vehicle travels in the direction of arrow R5. The driven roller 5d
And a pressing roller (primary transfer roller) 5j that retreats so as to take a position where the intermediate transfer belt 5a is pressed against the photosensitive drum 1 in close proximity to the photosensitive drum 1 and a position where the intermediate transfer belt 5a is separated from the photosensitive drum 1. .

On the other hand, at a predetermined position outside the intermediate transfer belt 5a, there is provided a cleaning unit 5e capable of coming in contact with and separating from the surface of the intermediate transfer belt 5a. After performing the secondary transfer, the transfer residual toner remaining on the intermediate transfer belt 5a is removed.

Here, the cleaning unit 5e has a charging roller 5f, and the charging roller 5f is brought into contact with the intermediate transfer belt 5a so as to apply a charge to the toner opposite to that at the time of transfer. Then, when the opposite charge is applied by the charging roller 5f, the toner is electrostatically attached to the photosensitive drum 1 and then collected by the cleaning device 6. The method of cleaning the intermediate transfer belt 5a is not limited to the electrostatic cleaning described above, but may be a mechanical method such as a blade or a fur brush, or a method using both of them.

The cleaning device 6 includes the developing device 4
After the toner developed on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 5a, the so-called transfer residual toner remaining on the surface of the photosensitive drum 1 without being primary-transferred is removed. A cleaning container 11a for storing toner is provided.

In the figure, reference numeral 7 denotes a feeding / conveying means for feeding the transfer material S to a nip portion between the intermediate transfer unit 5 and the photosensitive drum 1, and this feeding / conveying means 7 comprises a plurality of transfer materials. S, a paper feed cassette 7a, a pickup roller 7e (half moon roller), a feed roller 7
f, a retard roller 7g and the like. During image formation, the pickup roller 7e and the feed roller 7
f, the retard roller 7g is driven and rotated in accordance with the image forming operation, separates and feeds the transfer material S in the sheet cassette 7a one by one, and transports the transfer material S along the guide plate 7c by the conveying roller pair 7b. It is designed to be transported.

When the transfer material S is separated and fed as described above, the leading end of the transfer material S abuts against the pair of registration rollers 7d and temporarily stops to form a loop. Then, rotation of the intermediate transfer belt 5a and image writing are performed. The sheet is re-fed to the intermediate transfer body 5 by the registration roller pair 7d in synchronization with the position.

In the same figure, reference numeral 8 denotes a fixing device for fixing a plurality of toner images secondary-transferred to the transfer material S. The fixing device 8 is in contact with a heating roller 8b and is pressed against the heating roller 8b. A fixing roller pair 8A including a pressure roller 8a for applying heat and pressure to S is provided. When the transfer material S transported by the transport belt unit 12 described later passes through the fixing device 8, heat and pressure are applied by the fixing roller pair 8A, so that the toner images of a plurality of colors are formed on the surface of the transfer material S. Has been established.

Next, the LBP 100 configured as described above
Will be described.

At the time of image formation, first, the photosensitive drum 1 is rotated in the direction of the arrow (counterclockwise) in FIG. 1 in synchronization with the rotation of the intermediate transfer belt 5a, and the surface of the photosensitive drum 1 is charged by the charging device 2.
And uniformly irradiate the yellow image with the exposure unit 3 to form a yellow electrostatic latent image on the photosensitive drum 1.

Further, simultaneously with the formation of the electrostatic latent image, the developing device 4 is driven to arrange the yellow developing device 4Y at the developing position so that the yellow toner adheres to the electrostatic latent image on the photosensitive drum 1. A voltage having the same polarity and substantially the same potential as the charging polarity of the photosensitive drum 1 is applied to cause the yellow toner to adhere to the electrostatic latent image for development. Thereafter, a voltage having a polarity opposite to that of the toner is applied to the pressing roller 5j of the intermediate transfer belt 5a to transfer the yellow toner image on the photosensitive drum 1 to the intermediate transfer belt 5a.
The primary transfer is performed thereon.

Next, when the primary transfer of the yellow toner image is completed in this way, thereafter, in the same manner as in the case of yellow, the formation, development, and formation of an electrostatic latent image for each of the colors magenta, cyan, and black are performed. The primary transfer is sequentially performed, and the toner images of four colors are superimposed on the intermediate transfer belt 5a.

While the four color toner images are formed on the intermediate transfer belt 5a, the secondary transfer roller 5n
Is in a non-contact state with the intermediate transfer belt 5a, and the charging roller 5f of the cleaning unit 5e is also in contact with the intermediate transfer belt 5a.
a is in a non-contact state. The transfer material S stored in the paper feed cassette 7a during this time is picked up by a pickup roller 7e.
The sheet is fed one by one by the retard roller 7g and the feed roller 7f, and stands by at a predetermined position near the registration roller pair 7d.

Next, the intermediate transfer belt 5a
After forming a four-color toner image thereon, the secondary transfer roller 5
n comes into pressure contact with the intermediate transfer belt 5a. Further, the transfer material S waiting at a predetermined position near the registration roller pair 7d is
Is sent out to a nip portion between the intermediate transfer belt 5a and the secondary transfer roller 5n in synchronization with the rotation of the intermediate transfer belt 5a.

Here, a voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 5n, whereby the toner image on the intermediate transfer belt 5a is collectively transferred onto the surface of the transferred transfer material S. The secondary transfer is performed.

After the secondary transfer is performed on the transfer material S in a lump, the cleaning unit 5e contacts the charging roller 56 to the intermediate transfer belt 5a to give the toner a charge opposite to that at the time of transfer. Then, the toner having the opposite charge is electrostatically attached to the photosensitive drum 1 and thereafter collected by the cleaning device 6 for the photosensitive drum 1.

Finally, the transfer material S thus secondary-transferred is conveyed to the fixing device 8 by the conveyer belt unit 12, where a plurality of color toner images are fixed.
The sheet is conveyed along the conveyance guide rib 15 via the sheet discharge roller pair 16 and is discharged by the sheet discharge roller pair 9 to the sheet discharge tray 10 in the upper portion of the apparatus main body, thereby completing the image forming operation.

FIG. 2 shows a conveying device arranged between the fixing device 8 and a secondary transfer roller 5n constituting a secondary transfer portion for transferring the toner image transferred to the intermediate transfer belt 5a to the transfer material S. FIG. 3 is a diagram illustrating a configuration of a transport belt unit 12 as a means, and the transport belt unit 12 includes a first transport unit 12A and a second transport unit 12B.

Here, the first transport section 12A transfers the transfer paper S discharged from the nip between the secondary transfer opposing roller 5c and the secondary transfer roller 5n of the intermediate transfer body unit 5 downward from the horizontal direction. After receiving the first transport belt 12a, the transport belt 12a is transported toward the second transport unit 12B, and includes a first transport belt 12a (endless belt) attached to the transport belt table 12c. In addition, the second transport unit 12B includes the first transport unit 12A.
After receiving the transfer paper S conveyed from the printer, the transfer paper S is conveyed toward the fixing device 8, and includes a second conveyance belt 12b (endless belt) attached to the conveyance belt table 12c.

In the present embodiment, the first transport section 12A is inclined downward so as to receive the transfer paper S discharged downward from the horizontal direction in the same posture, and the second transport section 12A is inclined downward. The portion 12B is thereafter inclined upward so as to convey the transfer paper S toward the nip portion 8d of the fixing roller pair 8A.

On the other hand, the first transport belt 12a is, as shown in FIG. 3 and FIG. 3, a central portion 20a of a drive shaft 20 provided at a connection portion between the first and second transport portions 12A and 12B, and a transport belt table. 12c and a first driven shaft 21 provided at the end of the secondary transfer roller on the secondary transfer roller side.
2b, the both ends 20b of the drive shaft 20 and the conveyor belt table 1
It is stretched between the second driven shaft 22 provided at the transfer device side end of 2c.

Further, at one end of the drive shaft 20, a coupling for transmitting the rotation of a drive gear 39 provided on the apparatus body side to the drive shaft 20 so as to drive the first and second conveyor belts 12a and 12b. When a rotational driving force is applied to the drive shaft 20 in the direction of arrow Y via the coupling portion 29, the first transport belt 12a and the second transport belt 12b transfer the transfer material S to the fixing device 8 It rotates in the direction of transport to the side.

Here, FIG. 4 is a view showing the structure of such a coupling part 29.
As shown in the drawing, the drive shaft 20 includes a cross-shaped rib structure 20c formed at one end of the drive shaft 20 and a cross-shaped groove structure 39a formed at the end of the drive gear 39 on the apparatus body side. is there.

The rib structure 20c of the drive shaft 20 and the groove structure 39a of the drive gear 39 are provided with play "a" and "b" in the thrust direction and the radial direction, respectively, so as to absorb positional deviation. Thereby, when the transport belt unit 12 is mounted on the apparatus main body 14 as described later, the transport belt table 12c can be positioned while reliably coupling the drive shaft 20 and the drive gear 39. .

On the other hand, the transport belt unit 12 is detachably attached to a transport belt table stay 34 provided on the apparatus main body 14 via a transport belt table 12c. For this reason, as shown in FIG. 2 and FIG.
0, 31, 32 and a boss 33 are provided.

When the conveyor belt unit 12 is mounted on the conveyor belt table stay 34, the conveyor belt table 1
Positioning holes 35, 3 provided in cut-and-raised portions of conveyor belt stay 34 by inserting ribs 30, 31, 32 of 2c.
6 and 37, the end faces 30a, 31a and 32a are inserted until they come into contact with the cut-and-raised portions of the conveyor belt table stay, while the boss 33 is protruded from one end of the conveyor belt table stay 34 as shown in FIG. The locking portion 40 is provided so as to be locked in the positioning groove 40a.

The transfer belt table 12c is formed by a mold (resin), and is provided with a plurality of transfer guide ribs 12r extending in the transfer sheet transfer direction. Then, after the transfer paper S has been lowered to a predetermined position along the transport guide rib 12r, the nip portion 8d of the fixing roller pair
It is guided upward toward.

Further, the transport belt table 12c is provided with a transport guide plate 41 pressed by a thin sheet metal between the plurality of transport guide ribs 12r, and the transport guide plate 41 is connected to the transport belt table 12c. At the time of attachment to the conveyor belt base stay 34, as shown in FIG.
To be grounded.

When the transport guide plate 41 is grounded to the apparatus main body 14 as described above, the transfer material S discharged from the intermediate transfer unit 5 in a substantially horizontal direction while being charged is transferred to the grounded transport guide. It is electrostatically attracted in the direction of the plate 41. As a result, the transfer material S becomes the first
It is stably conveyed on the conveyance guide rib 12r by the conveyance belt 12a and the second conveyance belt 12b.

On the other hand, in the present embodiment, the height h of the transport guide ribs 12r from the transport guide plate 41 is determined by the transfer material S deposited on the transport guide plate when the transfer material S is transported. Is set to a height that does not electrostatically attract the toner, for example, about 4 to 10 mm. And
By setting the height h of the conveyance guide rib 12r to such a height, even when toner is deposited on the conveyance guide plate due to long-term use, it is possible to prevent the back surface of the transfer material S from being stained by the toner. .

As described above, the transport belt unit 12 integrally provided with the transport guide plate 41 is connected to the apparatus main body 14.
By detachably attaching the conveyance guide plate 41 with the unit mounting operation, that is, by attaching the conveyance belt table 12c to the conveyance belt table 12c with the screw 38, the conveyance guide plate 41 can be easily grounded. Can be reduced. Further, the transport belt unit 12
Is detachably attached to the apparatus main body 14, the cleaning of the transport guide plate 41 is also simplified, and the accumulation of a large amount of toner can be prevented.

When the transport belt unit 12 is to be removed, the fixing device 8 is first pulled out in the direction of the arrow shown in FIG. 2 and is pulled out from the rear of the apparatus, and then the screw 38 is loosened from the rear of the apparatus. Slide in the direction of the arrow shown in FIGS. As a result, the positioning of the transport belt unit 12 and the transport belt table stay 34 and the coupling between the drive gear 39 on the apparatus main body side and the drive shaft 20 of the transport belt unit 12 are released, and the transport belt unit 12 can be pulled out to the rear of the apparatus. I can do it.

On the other hand, when the transport belt unit 12 is mounted on the apparatus main body 14, the transport belt unit 12 is first inserted into the apparatus main body from the rear of the apparatus, and the positioning of the transport belt unit 12 and the transport belt table stay 34 and the apparatus main body 14 are performed. The coupling between the side drive gear 39 and the drive shaft 20 of the transport belt unit 12 is performed. Next, the screw 38 is tightened to fix the conveyor belt unit 12 to the conveyor belt table stay 34, and the conveyor guide plate 41 is grounded. Finally, the fixing device 8 is inserted into the apparatus main body from the rear of the apparatus.

[0058]

As described above, according to the present invention, the sheet is conveyed to the fixing section by the conveying means provided between the fixing section and the transfer section, and the guide member provided on the conveying means is provided. When the height of the ribs is set so that the sheet does not electrostatically attract the toner accumulated on the conveyance guide plate when the sheet is conveyed, the toner accumulated on the conveyance guide plate is transferred. Adhesion to the back surface of the material can be prevented. Further, by providing a guide member integrally with the transporting means, detachably providing the transporting means to the apparatus main body, and grounding the transport guide plate with mounting the transporting means on the apparatus main body. In addition, the transfer guide plate can be easily grounded.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a four-color full-color laser beam printer as an example of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a transport belt unit of the laser beam printer.

FIG. 3 is a plan view of the transport belt unit.

FIG. 4 is a diagram showing a configuration of a coupling unit provided in the transport belt unit.

FIG. 5 is a diagram illustrating a state in which the transport belt unit is attached to a transport belt base stay.

FIG. 6 is a diagram showing a state in which the transport belt unit is detached from a transport belt stand.

FIG. 7 is another view showing a state in which the transport belt unit is detached from the transport belt stand.

FIG. 8 is a diagram illustrating a schematic configuration of a black and white laser printer as an example of an image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 5a Intermediate transfer belt 5n Secondary transfer roller 8 Fixing device 12 Conveyor belt unit 12c Conveyor belt stand 12r Conveyor guide rib 14 Device body 34 Conveyor belt stand stay 38 Screw 39 Drive gear 41 Conveyor guide plate 100 Laser beam printer

Claims (2)

[Claims] 1. An image forming apparatus, wherein a toner image formed by developing a latent image on an image carrier is transferred to a sheet by a transfer unit and then fixed to the sheet by a fixing unit. And a transfer unit provided between the transfer unit and the transfer unit for transferring the sheet on which the toner image has been transferred to the fixing unit; and a transfer unit provided on the transfer unit, the transfer unit being formed of an insulator and sliding the sheet. A guide member provided with a plurality of moving ribs and a transport guide plate provided between the ribs and formed of a conductor, and the transport guide plate of the guide member is grounded, and When transporting the sheet, the height of the rib,
An image forming apparatus, wherein the sheet has a height that does not electrostatically attract toner accumulated on a conveyance guide plate. 2. The apparatus according to claim 1, wherein the transport unit is provided integrally with the guide member and is detachably provided on the apparatus main body. The transport guide plate is grounded when the transport unit is mounted on the apparatus main body. The image forming apparatus according to claim 1, wherein: