JP2012230297A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a surface opposite to a guide surface of a conveyance guide to be exposed to a transfer roller side in a cartridge type image forming device in which a recording material introduction port is shielded by the conveyance guide for introducing a recording material into the recording material introduction port.SOLUTION: An image forming device has a conveyance guide 13 for guiding a recording material P passed through transfer means 11 into a recording material introduction port 14e of fixing means 14. The conveyance guide may be moved to a first position in which a rear surface opposite to a toner image forming surface of the recording material is guided by a guide surface 13a1 in a state where a cartridge 10 is mounted in an image forming device body 15 and a second position in which the recording material introduction port is shielded by exposing a surface 13a2 opposite to the guide surface so as to face the transfer means in a state where the cartridge is removed from the image forming device body.

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer in which a cartridge having an image carrier is detachably mounted. In particular, the present invention relates to an image forming apparatus configured to shield a recording material introduction port of a fixing device with a conveyance guide when a cartridge is removed.

  In an image forming apparatus such as an electrophotographic copying machine or a printer, a photosensitive drum as an image carrier and process means acting on the photosensitive drum are integrally formed into a cartridge, and the cartridge is detachably mounted on the main body of the image forming apparatus. A cartridge system is adopted. According to this cartridge type image forming apparatus, the maintenance of the image forming apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. Therefore, this cartridge system is widely used in image forming apparatuses.

  In the cartridge type image forming apparatus, when the cartridge is removed from the apparatus main body, the recording material conveyance path is exposed in the cartridge housing portion. Therefore, when the recording material is jammed in the apparatus main body, the user removes the cartridge, accesses the conveyance path from the cartridge storage portion, and performs a jam process for pulling out the jammed recording material from the apparatus main body. When the cartridge is removed, the fixing pressure roller and the fixing heating member that constitute the fixing device are also exposed to the cartridge housing portion. Therefore, there is a possibility that the user may touch the fixing heating member and the fixing pressure roller during the jam processing. is there. If the user touches it by mistake, there is a possibility that the fixing heating member or the fixing pressure roller may be damaged such as breakage.

  In Patent Document 1, a conveyance guide for introducing a recording material into a recording material introduction port of a fixing device is used in order to prevent a user from accidentally touching the fixing heating member and the fixing pressure roller of the fixing device. An image forming apparatus configured to shield the recording material introduction port is disclosed. According to this image forming apparatus, the conveyance guide is rotated so as to shield the recording material introduction port of the fixing device in conjunction with the opening operation of the cartridge cover or the removal operation of the cartridge.

Japanese Patent Laid-Open No. 10-240099

  In the above-described cartridge type image forming apparatus, it is considered that there is a possibility that the user may accidentally touch the conveyance guide when performing jam processing even if the recording material introduction port of the fixing device is shielded by the conveyance guide. There is a need. Therefore, in the conveyance guide, the opposite surface that is less affected by the temperature rise due to the heat of the fixing device is exposed to the transfer roller side than the guide surface that guides the back surface opposite to the toner image forming surface of the recording material. It is desired.

  An object of the present invention is to provide a cartridge-type image forming apparatus that shields a recording material introduction port by using a conveyance guide that introduces a recording material into a recording material introduction port of a fixing device. An object of the present invention is to provide an image forming apparatus in which the toner is exposed to the transfer roller side.

  In order to achieve the above object, the image forming apparatus according to the present invention comprises a cartridge having an image carrier, a cartridge detachably mounted on the image forming apparatus body, and a toner image carried by the image carrier. Transfer means for transferring onto the recording material, fixing means for fixing the toner image transferred onto the recording material to the recording material, and conveyance for guiding the recording material that has passed through the transfer means to the recording material introduction port of the fixing means A first position for guiding the back surface of the recording material opposite to the toner image forming surface with the guide surface in a state where the cartridge is mounted on the image forming apparatus main body, In a state where the cartridge is detached from the image forming apparatus main body, the surface opposite to the guide surface is exposed so as to face the transfer unit, and the recording material introduction port is exposed. And being movable to a second position where the shield.

  According to the present invention, in the cartridge type image forming apparatus in which the recording material introduction port is shielded by the conveyance guide for introducing the recording material into the recording material introduction port of the fixing device, the surface opposite to the guide surface of the conveyance guide is the transfer roller. An image forming apparatus exposed to the side can be provided.

(A) is a schematic configuration schematic diagram of an image forming apparatus according to Embodiment 1, and (b) is a schematic configuration schematic diagram of a process cartridge. FIG. 3 is an explanatory diagram illustrating a shielding state of a recording material introduction port of a fixing device by a transfer fixing guide of the image forming apparatus according to the first embodiment. Schematic configuration schematic diagram of an image forming apparatus according to Embodiment 2 FIG. 7 is an explanatory diagram illustrating a shielding state of a recording material introduction port of a fixing device by a transfer fixing guide of an image forming apparatus according to a second embodiment. Schematic configuration schematic diagram of an image forming apparatus according to Embodiment 3 Explanatory drawing showing the shielding state of the recording material introduction port of the fixing device by the transfer fixing guide of the image forming apparatus according to Embodiment 3.

[Example 1]
(1) Overall Configuration of Image Forming Apparatus FIG. 1A is a schematic configuration schematic diagram of an image forming apparatus according to this embodiment, and FIG. 1B is a schematic configuration schematic diagram of a process cartridge. FIG. 2 is an explanatory diagram illustrating a state in which the recording material introduction port of the fixing device is shielded by the transfer fixing guide of the image forming apparatus according to the present exemplary embodiment. The image forming apparatus of this embodiment is an electrophotographic laser beam printer.

  In the following description, regarding the image forming apparatus and members constituting the image forming apparatus, the longitudinal direction is a direction orthogonal to the recording material conveyance direction. The short direction (hereinafter also referred to as the width direction) is a direction parallel to the recording material conveyance direction.

  The image forming apparatus shown in this embodiment includes an image forming unit 30 that forms a toner image on a recording material P such as recording paper, and fixing as a fixing unit that fixes an unfixed toner image on the recording material P to the recording material. Part (fixing device) 14 and the like. Further, the image forming unit 30 and the recording material conveying unit 50 for conveying the recording material P to the fixing device 14 are provided. A control unit 100 includes a CPU and a memory such as a ROM and a RAM. The memory stores an image formation sequence, various programs necessary for image formation, and the like. The control unit 100 executes an image forming sequence in response to a print command output from an external device (not shown) such as a host computer.

  In the image forming apparatus of the present embodiment, when the image forming sequence is executed, the motor 19 is driven to rotate, the conveying roller 8, the photosensitive drum 10a as the image carrier, the pressure roller 14a as the fixing pressure member, and the discharge. The roller 16 is rotated in the direction of the arrow. Further, a predetermined one-rotation control mechanism is operated to rotate the feeding roller 7 once in the arrow direction. With the rotation of the feed roller 7, a feed cam (not shown) provided coaxially with the feed roller 7 rotates in the same direction so that the feed pressure plate 4 is rotatably coupled to the feed tray 1. Turn the device upward. By rotating the feeding pressure plate 4, the leading end side in the recording material conveyance direction of the plurality of recording materials P stacked and placed on the feeding pressure plate 4 is pressed against the outer peripheral surface of the feeding roller 7. The separation pad 6 is located at the outer peripheral surface position downstream of the feeding roller 7 in the rotation direction from the outer peripheral surface position where the recording material conveyance direction front end side of the plurality of recording materials P is pressed on the outer peripheral surface of the feeding roller 7. 5 is in contact with the power. When the feeding roller 7 starts to rotate, several recording materials P among the plurality of recording materials P are bundled and fed between the feeding roller 7 and the separation pad spring 5. When the feeding roller 7 further rotates, the uppermost recording material P of the bundle of recording materials P is fed to the conveying roller 8 by friction with the feeding roller 7. Immediately before the end of one rotation of the feeding roller 7, the feeding cam pushes down the feeding pressure plate 4 again to return it to the original standby position.

  The conveying roller 8 is formed of the outer peripheral surface (front surface) of the photosensitive drum 10a and the outer peripheral surface (front surface) of the transfer roller 11 as a transfer unit at a predetermined timing with respect to the recording material P fed from the feeding roller 7. It is conveyed to the transfer nip Tn. The recording material P conveyed by the conveying roller 8 is introduced into the transfer nip Tn after the recording material leading edge detection flag 9 is rotated and pushed down at the leading edge in the recording material conveying direction. A photosensor (not shown) is attached to the recording material leading edge detection flag 9, and the photosensor detects the leading edge position of the recording material P when the recording material leading edge detection flag 9 rotates. In FIG. 1, reference numeral 2 denotes a width regulating plate for user operation that can be moved in the longitudinal direction to prevent skewing when the recording material P is fed. Reference numeral 21 denotes a width regulating plate guide rail for guiding the width regulating plate 2 in the longitudinal direction. A recording material rear end regulating plate 3 is slidable in the short direction of the feeding tray 1. A feeding frame 22 supports the feeding pressure plate 4 and the separation pad spring 5. Reference numeral 22 a denotes a recording material tip set surface provided on the feeding frame 22.

  On the other hand, a charging roller 10c as a charging unit uniformly charges the surface of the photosensitive drum 10a to a predetermined polarity and potential by a predetermined charging bias applied from a charging bias power source (not shown). Then, after a predetermined time has elapsed since the leading edge of the recording material P is detected by the photosensor, the laser exposure device 20 as the exposure unit is turned on / off according to image information from the external device, and the laser beam 20a is controlled to turn on or off the photosensitive drum 10a. Scanning exposure is performed on the charged surface of the surface. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum. The toner container 10b is filled with toner. The toner container 10b has a toner supply member (not shown) inside the toner container 10b, and the toner supply member rotates in conjunction with the photosensitive drum 10a, thereby developing toner from the toner container 10b as developing means 10d. Is supplied to the outer peripheral surface. Then, an appropriate amount of toner is appropriately charged with the rotation of the developing roller 10d that rotates in conjunction with the photosensitive drum 10a, and then the toner on the developing roller 10d adheres to the electrostatic latent image on the photosensitive drum 10a and is electrostatically charged. The latent image is developed as a toner image. A predetermined transfer bias is applied to the transfer roller 11 from a transfer bias power source (not shown) in the conveyance process in which the recording material P is conveyed at the transfer nip Tn. The toner image on the surface of the photosensitive drum 10a is transferred onto the recording material P by this transfer bias. The recording material P carrying the unfixed toner image transferred from the surface of the photosensitive drum 10a is weakened in the electrostatic attraction force with the surface of the photosensitive drum 10a by the neutralizing needle 112 as a neutralizing means, and the leading end of the recording material P in the transport direction. Is separated from the surface of the photosensitive drum 10a. Then, the recording material P is introduced into a fixing nip portion N to be described later through a recording material introduction port 14 e of the fixing device 11 on the guide surface 13 a 1 of the recording material guide portion 13 a of the transfer fixing guide 13 as a conveyance guide. The static elimination needle 112 and the transfer fixing guide portion 13 are provided on the feeding frame 22 between the transfer roller 11 and the fixing device 14.

  The fixing device 14 includes a heater 14d that generates heat when energized, a cylindrical fixing heating member 14b that rotates while contacting the heater 14d, and a fixing pressurization that forms a fixing nip N together with the heater 14 via the fixing heating member 14b. It has a roller 14a and the like. The fixing heating member 14b follows the rotation of the fixing pressure roller 14a when the outer peripheral surface (surface) of the fixing heating member 14b receives a rotational force from the outer peripheral surface (surface) of the fixing pressure roller 14a through the fixing nip N. Rotate in the direction of the arrow. The recording material P introduced into the fixing nip N is nipped and conveyed between the surface of the fixing pressure roller 14a and the surface of the fixing heating member 14b, and heat and pressure are applied in this conveyance process, and the toner image on the recording material P is recorded. Heat-fixed on the material. The recording material P on which the toner image is heated and fixed is discharged by a discharge roller 16 onto a discharge stacking surface formed by a cartridge cover 17 and a discharge tray 18 outside the apparatus. The untransferred toner remaining on the surface of the photosensitive drum 10a without being transferred is stored in the waste toner container 10e by the cleaning blade 10f. The photosensitive drum 10a whose surface has been cleaned is used for the next image formation.

(2) Process cartridge 10
In the image forming apparatus of this embodiment, the photosensitive drum 10a, the toner container 10b, the charging roller 10c, the developing roller 10d, the toner supply member, the cleaning blade 10f, and the waste toner container 10e are integrated as a cartridge 10. It is configured. The cartridge 10 is detachably mounted in a cartridge housing portion S provided inside an image forming apparatus main body (hereinafter referred to as an apparatus main body) 15 that constitutes a housing of the image forming apparatus. That is, the cartridge 10 includes a first side cover (not shown) that rotatably supports one end of the photosensitive drum 10a in the axial direction, and a second side that rotatably supports the other axial end of the photosensitive drum 10a. It has a cover (not shown). The first side cover and the second side cover are each provided with a protrusion 10g coaxially with the rotational axis of the photosensitive drum 10a. On the other hand, in the cartridge housing portion S, the first inner wall surface facing the first side cover of the cartridge 10 and the second inner wall surface facing the second side cover of the cartridge 10 are respectively provided with protrusions 10g. A guide groove 23 for guiding the guide is formed. When removing the cartridge 10 from the apparatus main body 15, the user first opens the cartridge cover 17 provided in the apparatus main body 15 so as to be openable and closable from a closed position indicated by a solid line with a cover shaft (not shown) as a fulcrum. Rotate to position and open. Next, the cartridge 10 set at the image forming position in the cartridge storage portion S is pulled upward and obliquely to the right along the guide groove 23 from the image forming position and pulled out of the apparatus main body 15. The image forming position is a position where the photosensitive drum 10 a of the cartridge 10 forms the above-described transfer nip portion Tn together with the transfer roller 11. When the cartridge 10 is attached to the apparatus main body 15, first, the cartridge cover 17 is rotated to the open position indicated by a one-dot chain line to open. Next, the protrusion 10 g of the cartridge 10 is fitted into the guide groove 23 from the upper right side of the apparatus main body 15. Then, when the cartridge 10 is pushed down to the image forming position of the cartridge storage portion S along the guide groove 23, the cartridge 10 is set at the image forming position indicated by the solid line. After the cartridge 10 is set at the image forming position, the cartridge cover 17 is rotated from the open position indicated by the alternate long and short dash line to the closed position indicated by the solid line with the cover shaft as a fulcrum.

(3) Jam Processing Method In the image forming apparatus according to this embodiment, the conveyance path of the recording material P is exposed to the cartridge housing portion S when the cartridge 10 is detached from the apparatus main body 15. Therefore, the user removes the cartridge 10, accesses the conveyance path from the cartridge storage unit S, and performs jam processing for pulling out the jammed recording material (hereinafter referred to as jammed paper) from the apparatus main body 15. In order to prevent the user from touching the fixing pressure roller 14 a and the fixing heating member 14 b of the fixing device 14 when performing jam processing, the image forming apparatus of this embodiment uses the transfer fixing guide 13. A configuration in which the recording material introduction port 14e of the fixing device 14 is shielded is employed. It is necessary to consider that the user may accidentally touch the transfer and fixing guide 13 when performing the jam processing. Therefore, the non-guide surface (surface) 13a2 opposite to the guide surface 13a1 of the recording material guide portion 13a of the transfer fixing guide 13 is exposed so as to face the transfer roller 11. Since the non-guide surface 13a2 is on the opposite side of the guide surface 13a1 in the recording material guide portion 13a, the non-guide surface 13a2 is a surface less affected by the temperature rise due to the heat of the fixing device 14 than the guide surface 13a1. Hereinafter, the configuration of the transfer fixing guide 13 and the recording material introduction port shielding operation of the transfer fixing guide 13 will be described.

3-1) Configuration of Transfer Fixing Guide 13 As shown in FIG. 1, the transfer fixing guide 13 has a plate-shaped recording material guide portion 13a that is long in the longitudinal direction. The length of the recording material guide portion 13a in the longitudinal direction is substantially equal to the longitudinal width of the recording material P perpendicular to the recording material conveyance direction. At both ends in the longitudinal direction of the recording material guide portion 13a, lever portions 13d longer than the length of the recording material guide portion 13a are provided. A rotation support shaft 13c provided at an end of the lever portion 13d on the recording material guide portion 13a side is rotatably coupled to the feeding frame 22. A transfer / transfer fixing guide spring 25 (see FIG. 2) is hooked between the lever portion 13d and the apparatus main body 15, whereby the transfer / fixing guide 13 shields the recording material introduction port 14e of the fixing device 14 (counterclockwise in FIG. 1). Rotating direction). The rotation area of the transfer / fixing guide 13 biased by the transfer / transfer / fixing guide spring 25 is the transfer fixing guide 13 indicated by the solid line in FIG. 2 from the opening opening position of the transfer / fixing guide 13 indicated by the solid line in FIG. This is a region up to the inlet shielding position. The lever portion 13d of the transfer fixing guide 13 is in contact with the protruding portion 10g of the cartridge 10 at the inlet opening position, whereby the transfer fixing guide 13 is positioned at the inlet opening position by the cartridge 10. The lever portion 13d of the transfer and fixing guide 13 is in contact with the fixing cover 14c provided in the apparatus main body 15 at the introduction port shielding position, whereby the transfer and fixing guide 13 is positioned at the introduction port shielding position by the fixing cover 14c.

3-2) Introduction Port Shielding Operation of Transfer Fixing Guide 13 As shown in FIG. 1, when the cartridge 10 is mounted at the image forming position of the apparatus main body 15, the protrusion 10 g of the cartridge 10 is formed by the transfer transfer fixing guide spring 25. The lever portion 13d of the transfer fixing guide 13 is in contact with the urging force. As a result, the transfer fixing guide 13 is supported at an optimal position for introducing the recording material P into the recording material introduction port 14e. That is, the transfer and fixing guide 13 can be rotated (moved) to the first position where the back surface of the recording material P opposite to the toner image forming surface is guided by the guide surface 13a1 in a state where the cartridge 10 is mounted on the apparatus main body 15. Possible).

  A case where the user accesses the inside of the apparatus main body 15 in order to remove the jammed paper will be described with reference to FIG. First, in order to take out the cartridge 10, the cartridge cover 17 is opened. Next, the cartridge 10 is taken out from the cartridge housing portion S to the outside of the apparatus main body 15. At this time, the protrusion 10 of the cartridge 10 guided by the guide groove 23 of the apparatus body 15 is in contact with the lever portion 13 d of the transfer fixing guide 13 biased by the transfer fixing guide spring 25. For this reason, the transfer and fixing guide 13 rotates (moves) counterclockwise around the rotation support shaft 13c as it moves obliquely upward to the right when the cartridge 1 is removed. Then, before the protruding portion 10 of the cartridge 10 comes out of the guide groove 23 of the apparatus main body 15, the lever portion 13d of the transfer fixing guide 13 comes into contact with the fixing cover 14c, and the counterclockwise rotation of the transfer fixing guide 13 is stopped. . As a result, the transfer fixing guide 13 is positioned at the introduction port shielding position by the fixing cover 14. At this introduction port shielding position, the transfer fixing guide 13 shields the recording material introduction port 14 e so that the non-guide surface 13 a 2 of the conveyance guide portion 13 a of the transfer fixing guide 13 is exposed to face the transfer roller 11. That is, the transfer / fixing guide 13 exposes the non-guide surface 13a2 opposite to the guide surface 13a1 so as to face the transfer roller 11 in a state where the cartridge 10 is detached from the apparatus main body 15, thereby shielding the recording material introduction port 14e. It can be rotated to a second position.

  When the cartridge 10 is detached from the apparatus main body 15, the recording material introduction port 14 e of the fixing device 14 is shielded by the conveyance guide portion 13 a of the transfer fixing guide 13. For this reason, even if the user accesses the inside of the cartridge housing portion S to perform jam processing, the user does not touch the fixing pressure roller 14a or the fixing heating member 14b. Further, since the non-guide surface 13a2 of the conveyance guide portion 13a that does not receive heat directly from the fixing device 14 is exposed so as to face the transfer roller 11 in the cartridge storage portion S accessible by the user, the jamming process is performed. The influence on the user due to the heat of the fixing device 14 can be reduced.

  The transfer / fixing guide 13 is in a state where the recording material introduction port 14e is shielded by the conveyance guide portion 13a, and the user cannot access the inside of the fixing device 14 between the conveyance guide portion 13a and the fixing cover 14c. A slight gap c (see FIG. 2) that can pass is formed. In a state where the recording material introduction port 14e of the fixing device 14 is shielded by the conveyance guide portion 13a of the transfer fixing guide 13, a gap c through which the recording material P can pass is formed in a part of the shielded recording material introduction port 14e. It is desirable. When the operation of the image forming apparatus stops and a jam occurs with the leading edge of the recording material P protruding from the discharge roller 16 to the outside of the apparatus main body 15, the jammed paper is discharged with the cartridge 10 removed from the apparatus main body 15. It may be pulled out from the 16 side in the transport direction. When the recording material conveyance direction rear end of the conveyance guide portion 13a is brought into contact with the recording material conveyance direction rear end of the fixing cover 14c and the recording material introduction port 14e is shielded, the conveyance guide portion 13a and the fixing cover 14c jam the jammed paper. The rear end will be sandwiched. When the jammed paper is pulled out in the recording material conveyance direction, the unfixed toner on the recording material P scatters and adheres to the fixing cover 14c due to an impact when the recording material P is pulled out. In the image forming apparatus according to the present exemplary embodiment, in a state where the recording material introduction port 14e of the fixing device 14 is shielded by the conveyance guide portion 13a of the transfer fixing guide 13, the recording material P is formed in a part of the shielded recording material introduction port 14e. Is formed through the gap c. As a result, when the jammed paper is pulled out in the recording material conveyance direction, it is possible to prevent the unfixed toner on the recording material P from scattering and adhering to the fixing cover 14c.

  The image forming apparatus according to the present exemplary embodiment has a configuration in which the transfer and fixing guide 13 is retracted from the introduction port shielding position in conjunction with the operation of mounting the cartridge 10 in the cartridge storage portion S in the apparatus main body 15. Therefore, it is not necessary to separately secure a rotation area of the transfer and fixing guide 13 that serves to shield the recording material introduction port 14e of the fixing device 14, and the image forming apparatus can be downsized.

  In the image forming apparatus according to the present exemplary embodiment, when the cartridge 10 is removed and the user can access the cartridge storage unit S in the apparatus main body 15, the recording of the fixing unit 14 is performed by the conveyance guide unit 13 a of the transfer fixing guide 13. The material inlet 14e is shielded. In this shielded state, the non-guide surface 13a2 that is less affected by the temperature rise due to heat of the fixing device 14 of the conveyance guide portion 13a is exposed so as to face the transfer roller 11. For this reason, in addition to the effect of preventing the user from touching the fixing pressure roller and the fixing heating member of the fixing device when the user accesses the cartridge storing section by jamming or the like, the temperature rise of the cartridge storing section can be suppressed. It is possible to improve the jam handling workability. Further, since it is possible to prevent the user from touching the guide surface 13a1 of the conveyance guide portion 13a, it is possible to reduce the influence on the user due to the heat of the fixing device during the jam processing.

[Example 2]
Another example of the image forming apparatus will be described. FIG. 3 is a schematic configuration diagram of the image forming apparatus according to the present embodiment. FIG. 4 is an explanatory diagram showing the shielding state of the recording material introduction port of the fixing device by the transfer fixing guide of the image forming apparatus according to the present embodiment.

  The image forming apparatus according to the present exemplary embodiment is the same as the image forming apparatus according to the first exemplary embodiment except that the transfer and fixing guide 13 forms a part of the air path A (see FIG. 3) provided inside the apparatus main body 15. It has the same configuration as The conveyance guide portion 13a of the transfer fixing guide 13 is provided with a hole 13e that penetrates the conveyance guide portion 13a from the guide surface 13a1 to the non-guide surface 13a2. The hole 13 e forms an air passage A for cooling the inside of the apparatus main body 15 by the hole 22 e provided in the feeding frame 22 and the hole 15 e provided in the apparatus main body 15. The hole 22e of the feeding frame 22 is provided so as to face the hole 13e of the transport guide portion 13a in a state where the transfer fixing guide 13 is positioned at the introduction port open position. The hole 15 e of the apparatus main body 15 is provided so as to face the hole 22 e of the feeding frame 22. The air taken in from the outside of the apparatus main body 15 into the apparatus main body 15 through the holes 15e and 22e passes through the holes 13e of the conveyance guide portion 13a, so that the temperature of the transfer fixing cover 13 is further suppressed. . When removing the jammed paper, the non-guide surface 13a2 of the transport guide portion 13a of the transfer and fixing cover 13 with the temperature rise suppressed, as in the image forming apparatus of Embodiment 1, the recording material introduction port 14e of the fixing device 14 is inserted. The lever portion 13d comes into contact with the fixing cover 14 so as to be shielded (see FIG. 4).

  In the image forming apparatus according to the present exemplary embodiment, in a state where the cartridge 10 is mounted in the apparatus main body 15, the holes 13 e provided in the conveyance guide portion 13 a of the transfer fixing guide 13 are provided in the holes 15 e provided in the apparatus main body 15. The air path A is formed with 22e. The temperature of the non-guide surface 13a2 of the conveyance guide portion 13a can be suppressed by the air passing through the air path A. Therefore, in the state where the cartridge 10 is removed from the apparatus main body 15 and the conveyance guide portion 13a of the transfer and fixing guide 13 shields the recording material introduction port 14e of the fixing device 14, the following effects are obtained. That is, the temperature of the non-guide surface 13a2 of the conveyance guide portion 13a exposed so as to face the transfer roller 11 in the cartridge storage portion S accessible by the user is suppressed to be lower than that of the image forming apparatus of the first embodiment. It has become possible. Therefore, according to the present embodiment, it is possible to provide an image forming apparatus that is more excellent in jam handling workability than the image forming apparatus of the first embodiment.

[Example 3]
Another example of the image forming apparatus will be described. FIG. 5 is a schematic configuration diagram of the image forming apparatus according to the present embodiment. FIG. 6 is an explanatory diagram showing a shielding state of the recording material introduction port of the fixing device by the transfer fixing guide of the image forming apparatus according to the present embodiment.

  In the image forming apparatuses according to the first and second embodiments, the tip of the charge removal needle 12 on the recording material P side needs to have a sharp shape in order to enhance the charge removal effect for separating the recording material P from the photosensitive drum 10a. Is done. In order to realize the shape, a thin metal such as SUS is generally used as the material (material) of the static elimination needle 12. Further, the tip of the static elimination needle 12 is set to a width substantially equal to the width orthogonal to the recording material conveyance direction of the recording material P in order to improve the static elimination performance. In the image forming apparatuses according to the first and second embodiments, when the cartridge 10 is detached from the apparatus main body 15 and the user can access the inside of the cartridge storage unit S, the user points the finger at the tip of the static elimination needle 12. There is a risk of catching. At this time, the static elimination needle 12 may be deformed. Due to the deformation of the static elimination needle 12, the static elimination performance is deteriorated.

  The image forming apparatus according to the third embodiment has the same configuration as that of the image forming apparatus according to the second embodiment except that the static elimination needle 12 is integrally provided on the transfer fixing guide 13. In a state where the cartridge 10 is mounted on the apparatus main body 15 and the recording material introduction port 14e of the fixing device 14 is shielded by the conveyance guide portion 13a of the transfer and fixing guide 13 (see FIG. 5), the static elimination needle 12 removes the recording paper P from the photosensitive drum. 10a is positioned at a position where electricity is removed from the surface. That is, the static elimination needle 12 is positioned at a position where the tip sharp portion 12a of the static elimination needle 12 intersects the conveyance path indicated by a two-dot chain line between the transfer nip portion Tn and the fixing device 14 via a predetermined gap. . The position where the static elimination needle 12 is positioned is a standby position of the static elimination needle 12, and a contact portion (not shown) formed in a part of the static elimination needle 12 at this standby position is provided on the feeding frame 22. A ground path with the image forming apparatus is formed in electrical contact with (not shown). In a state where the cartridge 10 is removed from the apparatus main body 15 and the conveyance guide portion 13a of the transfer fixing guide 13 opens the recording material introduction port 14e of the fixing device 14 (see FIG. 6), the static elimination needle 12 does not face the transfer roller 11. Positioned. That is, the static elimination needle 12 is positioned at a position where the tip sharp portion 12a of the static elimination needle 12 intersects the back surface of the fixing cover 14c contacting the lever portion 13d of the transfer fixing guide 13 with a predetermined gap. The above-mentioned position where the static elimination needle 12 is positioned is a position where the tip of the static elimination needle 12 cannot be touched when the user can access the cartridge storage portion S.

  In the image forming apparatus according to the present exemplary embodiment, the static elimination needle 12 is provided integrally with the transfer fixing guide 13. In a state where the cartridge 10 is mounted on the apparatus main body 15 and the recording material introduction port 14e is shielded by the conveyance guide portion 13a of the transfer and fixing guide 13, the static elimination needle 12 is positioned at a position where the recording paper P is neutralized from the surface of the photosensitive drum 10a. Is done. In a state where the cartridge 10 is detached from the apparatus main body 15 and the conveyance guide portion 13a of the transfer fixing guide 13 opens the recording material introduction port 14e, the static elimination needle 12 is positioned at a position not facing the transfer roller 11. Therefore, when the cartridge 10 is detached from the apparatus main body 15 and the user can access the inside of the cartridge housing portion S, damage to the static elimination needle 12 due to the user's contact can be avoided. Therefore, according to this embodiment, it is possible to provide an image forming apparatus that is more excellent in jam handling workability than the image forming apparatus of the second embodiment.

  In this embodiment, the example in which the charge eliminating needle 12 is integrally provided in the transfer fixing guide 13 in the image forming apparatus according to the second embodiment has been described. However, in the image forming apparatus according to the first embodiment, the charge eliminating needle 12 is provided in the transfer fixing guide 13. Even if they are provided integrally, the same effect can be obtained.

DESCRIPTION OF SYMBOLS 10 ... Cartridge, 10a ... Photosensitive drum, 11 ... Transfer roller, 12 ... Static elimination needle, 13 ... Transfer fixing guide, 13a1 ... Guide surface, 13a2 ... Non-guide surface, 14 ... Fixing device, 15 Image forming device body, A Air path, c Air gap

Claims (4)

  A cartridge having an image carrier, which is detachably mounted on the image forming apparatus main body, a transfer means for transferring a toner image carried by the image carrier onto a recording material, and a toner transferred onto the recording material A fixing unit that fixes the image on the recording material; and a conveyance guide that guides the recording material that has passed through the transfer unit to a recording material introduction port of the fixing unit. The conveyance guide is configured so that the cartridge forms the image. A first position that guides the back surface of the recording material opposite to the toner image forming surface of the recording material with the guide surface when the recording material is mounted on the apparatus main body; and the guide surface when the cartridge is detached from the image forming apparatus main body. An image shape characterized by being movable to a second position where the opposite surface is exposed so as to face the transfer means and the recording material introduction port is shielded. Apparatus.   The image forming apparatus according to claim 1, wherein the conveyance guide forms a gap through which the recording material can pass in a part of the blocked recording material introduction port at the second position.   The image forming apparatus according to claim 1, wherein the conveyance guide forms a part of an air path provided inside the image forming apparatus main body at the first position.   A neutralization unit for separating the recording material from the image carrier is provided in the conveyance guide, and the neutralization unit is a position for neutralizing the recording material from the image carrier at the first position of the conveyance guide. The image forming apparatus according to claim 1, wherein the image forming apparatus is positioned at a position that is not opposed to the transfer unit at the second position of the conveyance guide.