JP6314536B2 - Unit and image forming apparatus - Google Patents

Description

  The present invention relates to a unit that can be attached to and detached from an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine thereof, and an image forming apparatus including the unit.

  In an image forming apparatus such as a copying machine or a printer, a method is often adopted in which a plurality of apparatuses and members are unitized and can be integrally attached to and detached from the image forming apparatus main body for replacement and maintenance. . Representative examples of what is unitized include, for example, a process unit in which a photosensitive member and process means acting thereon are unitized, and an intermediate transfer unit in which an intermediate transfer belt and its peripheral members are unitized. In addition, in an image forming apparatus including such a unit, a configuration is known in which a part of the exterior is a cover member that can be opened and closed, and the unit is detachable through an opening formed by opening the cover member.

  In Patent Document 1, when the cover member (door) is opened, an opening is formed, and the secondary transfer roller and the like are retracted from the front of the intermediate transfer unit together with the cover member. A configuration is described in which the intermediate transfer unit can be attached and detached without interfering with. Further, in this configuration, the fixing device and its peripheral members are also moved together with the cover member.

  If the fixing device and its peripheral members are movable together with the cover member as in the configuration described in Patent Document 1, a large entrance / exit for attaching / detaching the unit can be secured, so that the intermediate transfer belt can be attached / detached. Work becomes easier.

  However, it is not preferable from the viewpoint of safety that the fixing device that becomes high temperature is exposed following the opening operation of the cover member. Further, since the fixing device is a relatively heavy device, when the fixing device is provided on the cover member, it is difficult to operate the cover member, and there is a possibility that the cover member may be damaged due to a load. Further, when the fixing device is provided on the cover member, it is necessary to provide a power supply path from the power supply on the image forming apparatus main body side to the fixing device in the cover member, and it is easy to install the power supply path on a movable member such as the cover member. There is also a problem that is not.

  Therefore, in consideration of safety, operability and durability of the cover member, difficulty in installing the power supply path, etc., it is preferable to install the fixing device on the image forming apparatus main body without providing the cover member. However, on the other hand, when the fixing device is installed on the image forming apparatus main body, the entrance for attaching / detaching the unit is narrowed by the fixing device, which causes a problem that it becomes difficult to attach / detach the unit.

  Therefore, in view of such circumstances, the present invention intends to provide a unit that can be easily attached and detached from between the opened cover member and the fixing device provided in the main body of the image forming apparatus, and an image forming apparatus including such a unit. To do.

In order to solve the above-described problems, the present invention is configured to be detachable from an image forming apparatus that includes a fixing device that fixes an image on a recording medium and a cover member that can be opened and closed on the image forming apparatus main body. And a guide member for guiding the recording medium, wherein the guide member has a first position where the recording medium can be guided from the unit to the fixing device, and the unit is taken out from the first position. The cover member and the image forming apparatus are configured to be movable between a second position positioned in a direction, the cover member is opened, and the guide member is moved to the second position. It is configured to be detachable from the fixing device provided in the main body.

  In this invention, a guide member can be arrange | positioned rather than a 1st position in a unit taking-out direction by moving a guide member to a 2nd position. That is, since the guide member is disposed at a position where the worker can easily reach, the operator can attach and detach the unit by gripping the guide member. Accordingly, the unit can be easily attached and detached between the opened cover member and the fixing device provided in the image forming apparatus main body.

1 is a schematic configuration diagram of a monochrome printer as an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the printer with a cover member opened. FIG. 3 is a perspective view of the printer with a cover member closed. FIG. 2 is a perspective view of the printer with a cover member opened. It is an enlarged view of a guide member periphery. It is a schematic block diagram of the process unit which concerns on embodiment of this invention. It is a figure for demonstrating the attachment or detachment method of a process unit. It is a figure which shows embodiment which provided the protrusion in the guide member. It is a figure which shows embodiment which a guide member has two guide surfaces. FIG. 2 is a diagram illustrating a state where a process unit is mounted on an image forming apparatus main body. It is a figure which shows embodiment which provided the processus | protrusion in the guide member which has two guide surfaces. It is a schematic block diagram of the printer using the exposure apparatus provided with LED. It is a figure for demonstrating the attachment or detachment method of a process unit. It is a schematic block diagram of a printer provided with a duplex printing function. It is an enlarged view of a guide member periphery.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, components such as members and components having the same function or shape are denoted by the same reference numerals as much as possible, and once described, the description is omitted.

FIG. 1 is a schematic configuration diagram of a monochrome printer as an image forming apparatus according to an embodiment of the present invention.
In the following description, “image forming apparatus” refers to an apparatus that forms an image by attaching toner or ink as a developer to a sheet that is a recording medium for recording an image. “Image formation” not only means that an image having a meaning such as a character or a figure is given to the medium but also an image having no meaning such as a pattern is given to the medium. The “sheet” is not limited to paper (paper) but also includes OHP sheets, fabrics, and the like, and means a medium or an original on which a developer can be attached. In addition to plain paper, “paper” includes cardboard, postcard, envelope, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, and the like. In the following embodiment, “developer” is described as toner, and sheet is “paper”, and the dimensions, materials, shapes, relative arrangements, and the like in the description of each component are examples, and are particularly specific. Unless stated otherwise, the scope of the present invention is not intended to be limited thereto.

  The printer shown in FIG. 1 includes a process unit 1 for forming an image with a black developer in the image forming unit. The process unit 1 includes a photosensitive member 2 as a latent image carrier that carries a latent image on the surface, a charging device 3 as a charging unit that charges the surface of the photosensitive member 2, and toner that is a developer on the photosensitive member 2. Developing device 4 as a developing means for forming an image (developer image), a drum cleaning device (not shown) as a cleaning means for cleaning the surface of photoconductor 2, and an illustration for discharging the surface of photoconductor 2. It has a static eliminator that does not. The process unit 1 is configured to be detachable from the image forming apparatus main body 100 so that consumable parts can be replaced at a time.

  An exposure device 6 that exposes the surface of the photoreceptor 2 is disposed on the right side of the drawing with respect to the process unit 1. The exposure device 6 is configured to emit laser light L from the laser diode to the surface of the photoreceptor 2 based on the image data. Further, on the left side of the drawing with respect to the process unit 1, a transfer roller 7 is disposed as a transfer unit that transfers an image on the photosensitive member 2 to a sheet. The transfer roller 7 is disposed at a position where the transfer roller 7 can come into contact with the photoreceptor 2, and a transfer nip is formed at the contact portion between the two.

  Under the image forming apparatus main body 100, a feeding roller 9 is disposed as a feeding unit that feeds the paper P placed on the paper feed tray 8. A timing roller that is downstream of the feeding roller 9 in the sheet conveyance direction and upstream of the transfer nip, temporarily stops the sheet fed by the feeding roller 9 and then conveys the sheet at a predetermined timing. Pair 10 is arranged.

  Further, a fixing device 11 for fixing the image transferred to the paper is disposed downstream of the transfer nip in the paper conveyance direction, and further, on the downstream side, paper discharge as a discharge means for discharging the paper to the outside of the device. A roller pair 14 is arranged. The fixing device 11 includes a fixing roller 12 that includes a heat source such as a halogen lamp (not shown), and a pressure roller 13 that rotates while contacting the fixing roller 12 with a predetermined pressure. In addition, a paper discharge tray 15 on which the paper discharged outside the apparatus is placed is arranged on the upper part of the image forming apparatus main body 100.

Next, the basic operation of the printer according to the present embodiment will be described with reference to FIG.
When the feed roller 9 is rotated by a paper feed signal from a control unit (not shown), only the uppermost paper P stacked on the paper feed tray 8 is separated and sent out. When the leading edge of the sheet P reaches the nip portion of the timing roller pair 10, a slack is formed on the sheet P in order to take timing (synchronization) with the toner image formed on the photoreceptor 2 and to correct the leading edge skew of the sheet P. Wait in the state.

  The image forming operation will be described. First, the charging device 3 charges the surface of the photoreceptor 2 to a uniform high potential. Next, based on image information from a reading device or a computer (not shown), the exposure device 6 irradiates the surface of the photoreceptor 2 with the laser beam L, and the potential of the irradiated portion is lowered to form an electrostatic latent image. Is done. To this electrostatic latent image, toner is supplied by the developing device 4 to form (develop) a toner image (developer image).

  When the toner image is formed on the photosensitive member 2, the timing roller pair 10 and the feeding roller 9 start driving, and the paper P is sent to the transfer nip in synchronization with the toner image on the photosensitive member 2. Then, the transfer roller 7 transfers the toner image on the photoreceptor 2 to the fed paper P. The residual toner on the photosensitive member 2 that could not be transferred onto the paper P is removed by a drum cleaning device (not shown), and then the surface of the photosensitive member 2 is neutralized by a neutralizing device (not shown).

  The paper P on which the toner image is transferred is conveyed to the fixing device 11. The paper P sent to the fixing device 11 is sandwiched between the fixing roller 12 and the pressure roller 13, and the unfixed toner image is heated and pressed to be fixed on the paper P. Then, the paper P on which the toner image is fixed is discharged to the paper discharge tray 15 by the paper discharge roller pair 14.

  As shown in FIG. 1, an openable / closable cover member 16 is provided on the front portion (left side of the drawing) of the image forming apparatus main body 100. The cover member 16 is rotatable around a horizontal rotation shaft 17 provided at the lower front portion of the image forming apparatus main body 100.

  As shown in FIG. 2, when the cover member 16 is turned around the rotation shaft 17 so as to be tilted to the left side of the drawing, the cover member 16 is opened. 3 is a perspective view of the cover member 16 in a closed state, and FIG. 4 is a perspective view of the cover member 16 in an open state.

  The cover member 16 is provided with a transfer roller 7 and one timing roller 10. For this reason, when the cover member 16 is opened, the transfer roller 7 is separated from the photoreceptor 2 following this, and one timing roller 10 is separated from the other timing roller 10. As described above, in this embodiment, the transfer roller 7, the photosensitive member 2, and the timing roller 10 are separated from each other as the cover member 16 is opened. It is possible to remove.

  Further, by opening the cover member 16, an opening 18 is formed on the front surface of the image forming apparatus main body 100. Here, if the process unit 1 can be taken out to the front side through the opening 18, it is efficient because it is not necessary to provide another path or opening for taking out the process unit 1. If the process unit 1 is taken out, for example, upward rather than on the front side, it is necessary to secure a region A through which the process unit 1 is passed above the image forming apparatus. Then, the area A through which the process unit 1 passes becomes a dead space where no other device can be arranged, or even if another device is arranged, the device must be removed when the process unit 1 is attached or detached. Very cumbersome. In addition, a cover member that opens the upper part of the image forming apparatus main body 100 is required, and accordingly, an upper space for opening the cover member is also required, so that the space necessary for installing the apparatus is in the vertical direction. It becomes difficult to achieve the market demand for space saving in recent years. Therefore, it is desirable that the cover member 16 is provided on the front side and the process unit 1 is also taken out to the front side (the side opposite to the side where the exposure apparatus 6 is disposed).

  However, in this embodiment, the transfer roller 7 and the timing roller 10 are provided integrally with the cover member 16, whereas the fixing device 11 is not provided on the cover member 16 in consideration of safety and the like. The image forming apparatus main body 100 is stationary. For this reason, compared with the structure which provides a fixing device in a cover member, the vertical width of the opening part 18 becomes narrow, and it is the structure which cannot attach or detach the process unit 1 easily.

  Further, a guide member 19 is integrally provided in the process unit 1 (see FIG. 2), and a height Hp1 that is a distance dimension from the upper end portion of the guide member 19 to the lower surface of the casing of the process unit 1 is provided. Is higher than the height Hm1, which is the distance between the cover member 16 in the opened state and the fixing device 11 (opening 18). Therefore, in this state, the process unit 1 cannot be detached from the cover member 16 and the fixing device 11.

  Further, as shown in FIG. 5, the guide member 19 guides the leading edge Pa of the curled paper P, and prevents the paper P from entering the gap B between the process unit 1 and the fixing device 11. belongs to. If the guide member 19 is not provided, the curled paper P enters the gap B between the process uni 1 and the fixing device 11 (shown by the dotted line in FIG. 5), and there is a risk of paper conveyance failure or jamming. is there. Further, when the gap B between the process unit 1 and the fixing device 11 is eliminated, the guide member 19 is not necessary, but this gap B is a passage for airflow for insulating the heat of the fixing device 11. Necessary space. Therefore, the guide member 19 is an important member that is necessary to prevent the paper P from entering the gap B and is difficult to omit.

  In addition, the guide member 19 can be provided not in the process unit 1 but in the lower part of the fixing device 11 so that the height of the process unit 1 can be reduced. However, if a guide member is provided in the lower part of the fixing device 11, the height of the opening 18 is reduced by the length of the guide member (becomes Hm2). If the guide member is provided so as to protrude below the fixing device 11, the guide member may come into contact with the mounting surface and be damaged when the fixing device 11 is removed and placed. Therefore, providing the guide member 19 in the fixing device 11 is not a preferable solution.

  As described above, the image forming apparatus according to the present embodiment has a configuration in which the process unit 1 is difficult to attach and detach from the opening 18, but this problem is solved as follows. Hereafter, the characteristic part of this invention is demonstrated in detail.

  As shown in FIG. 6, in this embodiment, the guide member 19 is configured to be rotatable around a fulcrum 20 that is coaxial with the rotation axis of the photosensitive member 2. Thereby, the guide member 19 is between the first position arranged along the vertical direction (paper conveyance direction) indicated by the two-dot chain line and the second position inclined with respect to the vertical direction indicated by the solid line. It is movable. The process unit 1 is provided with a stopper (not shown) for holding the guide member 19 in the second position.

  Thus, the guide member 19 is movable between the first position and the second position, so that the height from the upper end of the guide member 19 to the lower surface of the casing of the process unit 1 changes. It is supposed to be. That is, when the guide member 19 is disposed at the second position, the height Hp2 is smaller than the height Hp1 when the guide member 19 is disposed at the first position. In the state where the guide member 19 is disposed at the second position, the guide member 19 is placed within the height Hp0 of the housing of the process unit 1.

Next, a process unit attaching / detaching method according to the present embodiment will be described.
As shown in FIG. 7, first, the cover member 16 is opened until it is in a horizontal state, and then the guide member 19 is rotated to move from the first position (the position indicated by the two-dot chain line in the figure) to the second position. Move to the position indicated by the solid line in the figure. In the state where the guide member 19 is moved to the second position, the guide member 19 is accommodated within the height Hp0 of the housing of the process unit 1. Further, the height Hp0 of the housing of the process unit 1 is smaller than the height Hm1 of the opening 18. That is, by moving the guide member 19 to the second position, the height of the process unit 1 including the guide member 19 becomes smaller than the height Hm1 of the opening 18, and the process unit 1 is removed from the opening 18. It becomes possible.

  Further, when the guide member 19 is moved to the second position, the guide member 19 is positioned in the removal direction (left side in the drawing) of the process unit 1 from the first position. As a result, the guide member 19 is disposed at a position where the operator's hand such as the user can easily reach, so that the operator can grasp the guide member 19 as a handle and remove the process unit 1 through the opening 18. .

  Conversely, when the process unit 1 is attached to the image forming apparatus main body 100, the guide member 19 disposed at the second position is held as a handle, and the process unit 1 is moved into the image forming apparatus main body 100 through the opening 18. To house. Then, with the process unit 1 mounted at a predetermined position, the guide member 19 is rotated and moved from the second position to the first position. Thereby, the guide member 19 is disposed at a position where the sheet can be guided. The guide member 19 is disposed at a position where it does not contact the image forming surface of the paper so as not to disturb the toner image before fixing. Moreover, since the guide member 19 is disposed at a position where it does not interfere with the cover member 16 (moving in the closing direction) by disposing the guide member 19 at the first position, the cover member 16 is closed in this state. Is possible.

  Further, the rotation operation of the guide member 19 may be performed by an operator directly operating the guide member 19, or the guide member 19 rotates in conjunction with the opening / closing operation of the cover member 16 via a link mechanism. You may make it do. Further, the guide member 19 may be automatically rotated by a biasing member such as a spring.

  As described above, in the present embodiment, the process unit 1 is attached and detached even from a relatively narrow opening between the cover member 16 and the fixing device 11 by arranging the guide member 19 at the second position. It is possible. That is, by arranging the guide member 19 at the second position, the height of the process unit 1 including the guide member 19 can be made smaller than the height of the opening 18, and the process unit 1 can be attached and detached through the opening 18. Can be dimensioned. When the guide member 19 is moved to the second position, the guide member 19 moves in the direction of taking out the process unit 1, so that the operator can hold the guide member 19 as a handle. Thereby, it becomes easy to attach and detach the process unit 1 from the opening 18.

  In the present embodiment, the fulcrum 20 serving as the rotation center of the guide member 19 is arranged coaxially with the rotation axis of the photosensitive member 2, so that even if the guide member 19 rotates, The distance from the surface of the photoreceptor 2 can be kept constant. As a result, it is possible to avoid contact with the photoreceptor 2 due to the rotation of the guide member 19 and to prevent the surface of the photoreceptor 2 from being damaged.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. Hereinafter, other embodiments of the present invention will be described. In addition, the same code | symbol is attached | subjected to the location which has the same function as said embodiment, and duplication description is abbreviate | omitted.

  In the embodiment shown in FIG. 8, the guide member 19 is provided with a protrusion 21 as a gripping part that is gripped by an operator when attaching and detaching. The protrusion 21 is provided on the non-guide surface 19b opposite to the guide surface 19a for guiding the sheet of the guide member 19 so as not to hinder the sheet conveyance. Thus, by providing the guide member 19 with the projection 21 as a grip portion, when the operator attaches or detaches the process unit 1, the projection 21 becomes a non-slip, and the guide member 19 can be securely gripped. It becomes possible. Furthermore, the protrusion 21 is provided on the end side of the guide member 19 that has moved to the second position, which is located in the process unit removal direction. That is, since the protrusion 21 is located at a position where the worker can easily reach, the protrusion 21 can be easily held. Moreover, since the protrusion 21 is also provided to reinforce the guide member 19, the reliability as a handle is improved. In the example shown in FIG. 8, only one protrusion 21 is provided, but a plurality of protrusions 21 may be provided.

  Next, in the embodiment shown in FIG. 9, the guide member 19 has two guide surfaces 19a and 19c facing the front and back surfaces of the paper. FIG. 10 shows a state in which the process unit 1 shown in FIG. 9 is mounted on the image forming apparatus main body 100 and the guide member 19 is arranged at a first position where the sheet can be guided.

  Incidentally, the curl of the paper includes a normal curl in which the front end of the paper curls to the image forming surface side, and a back curl in which the front end of the paper curls to the side opposite to the image forming surface side. Therefore, as in this embodiment, the guide member 19 has the two guide surfaces 19a and 19c, so that it is possible to guide the leading edge of either the positively curled paper or the backcurled paper. Further, when attaching or detaching the process unit 1, the operator uses the non-guide surfaces 19b and 19d on the opposite side of the guide surfaces 19a and 19c as a grip portion, so that the guide can be provided without touching the guide surfaces 19a and 19c. The member 19 can be gripped. In addition, in this case, since the strength of the guide member 19 is increased, reliability as a handle is also improved.

  Further, as in the embodiment shown in FIG. 11, in the guide member 19 having the two guide surfaces 19a and 19c, the non-guide surfaces 19b and 19d on the opposite side to the guide surfaces 19a and 19c are respectively provided for slip prevention. The protrusion 21 may be provided. In this case, since the anti-slip protrusions 21 are on both sides of the guide surface 19, the guide member 19 can be gripped more reliably, and the guide member 19 can be reinforced to improve reliability.

  The embodiment shown in FIG. 12 is different from the above embodiment in the configuration of the exposure apparatus 6. Here, the exposure apparatus 6 is provided with an LED. Specifically, the exposure apparatus 6 includes an LED array head 22 in which a large number of LEDs are arranged in the axial direction (main scanning direction) of the photoreceptor 2 and a holding member 23 that holds the LED array head 22 at one end. The holding member 23 is supported so as to be rotatable about the fulcrum 25 with respect to the image forming apparatus main body 100. Further, the other end portion of the holding member 23 opposite to the one end portion where the LED array head 22 is provided is held by a frame or the like of the image forming apparatus main body 100 via a spring 24 as a biasing member. One end portion of the holding member 23 provided with the LED array head 22 is disposed so as to protrude into the accommodation space 26 in which the process unit 1 is accommodated. Further, a hole 27 through which one end portions of the LED array head 22 and the holding member 23 can enter is formed in the housing of the process unit 1. As shown in FIG. 12, when the process unit 1 is attached to the image forming apparatus main body 100, the LED array head 22 and one end of the holding member 23 enter the hole 27 of the process unit 1, and the LED array head 22 It is arranged in a state (exposure position) close to the photoreceptor 2.

FIG. 13 is a diagram showing a state in which the process unit 1 is removed in the embodiment shown in FIG.
As shown in FIG. 13, in this embodiment as well, in the same manner as in the above-described embodiment, the guide member 19 is tilted obliquely and disposed at the second position, and the guide member 19 is gripped as a handle, whereby the image forming apparatus It can be removed from the main body 100. Specifically, the process unit 1 is moved to the side opposite to the side where the LED array head 22 is close to the photosensitive member 2 (left side in FIG. 13), so that the LED array head 22 is accompanied by the removal operation. Comes out of the hole 27 of the process unit 1. As a result, the process unit 1 and the LED array head 22 are separated from each other, and the LED array head 22 and the holding member 23 are left on the image forming apparatus main body 100 side. As described above, the process unit 1 can be detached from the side opposite to the side where the LED array head 22 is close to the photosensitive member 2, so that the LED array head 22 is not separately retracted from the photosensitive member 2. However, the process unit 1 can be taken out without interfering with the LED array head 22.

  On the other hand, when attaching the process unit 1, the process unit 1 is inserted into the image forming apparatus main body 100, so that the LED array head 22 enters from the hole 27 of the process unit 1. Then, the LED array head 22 is arranged at a position close to the photoreceptor 2 in a state where the attachment of the process unit 1 is completed. As described above, in the embodiment shown in FIGS. 12 and 13, the separation operation and the approaching operation of the LED array head 22 with respect to the photosensitive member 2 can be performed simultaneously with the attachment / detachment operation of the process unit 1. The evacuation operation 22 and the approaching operation 22 need not be performed separately, and the operability is excellent.

  Further, since the holding member 23 can be rotated around the fulcrum 25, when the process unit 1 is attached or detached, the angle of entry or retraction of the LED array head 22 into the hole 27 can be adjusted. it can. As a result, the process unit 1 can be mounted smoothly and the LED array head 22 can be prevented from being damaged. Furthermore, in the example shown in FIG. 12, the hole 27 and the holding member 23 have inclined surfaces 27 a and 23 a, respectively, and are formed so that the width becomes narrower in the direction in which the LED array head 22 enters. The LED array head 22 and the holding member 23 can easily enter the hole 27.

The present invention can also be applied to an image forming apparatus capable of duplex printing as shown in FIG.
When performing double-sided printing with the image forming apparatus shown in FIG. 14, first, similarly to the above, paper is fed from the paper feed tray 8, and the toner image on the photoreceptor 2 is transferred to the front surface of this paper. After that, the fixing device 11 fixes the image on the paper. Thereafter, the paper discharge operation by the paper discharge roller pair 14 is stopped halfway, and the paper discharge roller pair 14 is rotated in the reverse direction to switch back the paper. At this time, the switching member 28 is switched to guide the paper to the reverse conveyance path R2 different from the conveyance path R1 toward the fixing device 11. The sheet passes through the reverse conveyance path R2 and is conveyed again to the timing roller pair 10 with the front and back sides reversed. Then, the sheet passes through the conveyance path R1, and a toner image is transferred to the back side of the sheet, and after the image is fixed by the fixing device 11, the sheet is discharged onto the sheet discharge tray 15. In this way, a series of double-sided printing operations are completed.

  Further, here, as shown in FIG. 15, for the positively curled paper P <b> 1, the guide member 19 is disposed between the process unit 1 and the fixing device 11 in the same manner as in the above-described embodiment, so that the paper P <b> 1 is prevented from entering between the process unit 1 and the fixing device 11. On the other hand, for the back-curled paper P2, another guide member 29 is disposed between the cover member 16 and the fixing device 11, so that the leading edge of the paper P2 is connected to the cover member 16 and the fixing device 11. It is possible to prevent entry during this period. As these guide members 19 and 29, for example, a plurality of ribs arranged in the paper width direction can be used.

  In recent years, various types of paper have been used in image forming apparatuses, and some types of paper have increased curl depending on the type of paper. In particular, when performing double-sided printing, the paper tends to curl due to the influence of the temperature difference between the fixing roller 12 and the pressure roller 13 and the shape of the nip portion between these rollers. Therefore, in an image forming apparatus having a double-sided printing function, a guide member is required between the fixing device and the process unit. Therefore, by applying the configuration of the present invention also to such an image forming apparatus, it can be expected that the detachability of the process unit is improved.

  In addition, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention. In the above-described embodiment, the guide member 19 is rotated when the guide member 19 is moved between the first position and the second position. However, the guide member 19 is moved to the first position by a slide movement or the like. You may make it move with a 2nd position. In the above-described embodiment, the height is reduced by moving the guide member 19 to the second position. However, the changing dimension may be the height or the width. Absent. Further, the present invention is not limited to the case where the present invention is applied to the guide member 19 provided integrally with the process unit 1. The present invention can be similarly applied to guide members provided integrally with other detachable units. The image forming apparatus according to the present invention is not limited to the monochrome printer as described above, but may be a color printer, or may be a copier, a facsimile, or a complex machine of these in addition to the printer.

1 process unit 2 photoconductor (latent image carrier)
6 exposure device 11 fixing device 16 cover member 18 opening 19 guide member 19a guide surface 19b non-guide surface 19c guide surface 19d non-guide surface 20 fulcrum 21 protrusion 22 LED array head 100 image forming apparatus main body P sheet (recording medium)

JP-A-8-272229

Claims (12)

A guide member that guides the recording medium and is configured to be detachable from an image forming apparatus that includes a fixing device that fixes an image on the recording medium and a cover member that is openable and closable on the main body of the image forming apparatus. A unit comprising:
The guide member is configured to be movable between a first position where the recording medium can be guided from the unit to the fixing device and a second position which is located in the unit removal direction from the first position. ,
The cover member is opened and the guide member is moved to the second position, and is configured to be detachable between the cover member and the fixing device provided in the image forming apparatus main body. A unit characterized by. Wherein the guide member is moved to said second position, the dimensions of the unit, according to claim 1 which is to be smaller than the distance dimension between the fixing device and the cover member state was opened unit.   The unit according to claim 1 or 2, wherein the guide member is configured to be movable between the first position and the second position by rotating the guide member.   The unit according to any one of claims 1 to 3, wherein the guide member is provided with a grip portion that is gripped when the unit is attached or detached.   The unit according to claim 4, wherein a protrusion as the grip portion is provided on a non-guide surface opposite to the guide surface of the guide member.   The unit according to claim 5, wherein the protrusion is provided on an end side of the guide member that has moved to the second position, the end being located in the unit extraction direction.   The unit according to claim 1, wherein the guide member has two guide surfaces facing the front and back surfaces of the recording medium.   The unit according to claim 7, wherein the two non-guide surfaces arranged on the opposite sides of the two guide surfaces are gripping portions that are gripped when the unit is attached and detached. A unit having a latent image carrier capable of carrying a latent image on its surface,
2. The guide member is configured to be movable between the first position and the second position by rotating about a fulcrum coaxial with the rotation axis of the latent image carrier. The unit according to any one of 8. The image forming apparatus includes an exposure device that exposes a surface of the latent image carrier.
The unit according to claim 9, wherein the unit can be attached to and detached from the image forming apparatus body from a side opposite to a side where the exposure apparatus is disposed. The exposure apparatus includes an LED,
The unit according to claim 10, wherein the unit is detachable from the side opposite to the side where the latent image carrier and the exposure device are close to the image forming apparatus main body.   An image forming apparatus comprising the unit according to claim 1.

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