JP6414417B2 - Image forming apparatus - Google Patents

Description

  The technology disclosed in this specification relates to an image forming apparatus.

  Among image forming apparatuses, there is an image forming apparatus that is configured such that the sheet conveyance path is folded back in a C-shape in order to reduce the size of the apparatus, and further has a function of forming images on both sides of the sheet ( For example, Patent Document 1). In this image forming apparatus, the conveyance path extends from the sheet placement portion to the outside of the housing of the device via a transfer position between the photosensitive member and the transfer portion. An image is formed on one surface of the sheet stored in the sheet placement portion while being folded back in a C shape along the conveyance path. The sheet on which the image is formed on one side is reversed in the traveling direction by the switchback means. The sheet whose traveling direction is reversed is conveyed along a double-sided conveyance path that joins the conveyance path via a photosensitive member and an exposure unit that exposes the photosensitive member, and is conveyed again to a transfer position. An image is formed on the other surface.

JP 2009-31508 A

  However, in the conventional image forming apparatus described above, the double-sided conveyance path is configured to pass between the photosensitive member and the exposure unit, and thus the following problem may occur. That is, when the leading edge of a sheet with an image formed on one side is conveyed again from the duplex conveyance path to the transfer position, the trailing edge of the sheet still passes between the photoconductor and the exposure unit. By not using the sheet, the light path for the exposure unit to expose the photosensitive member is blocked by the sheet, and there is a possibility that an image cannot be formed on the other surface.

  The present specification discloses a technique capable of solving at least a part of the problems described above.

(1) An image forming apparatus disclosed in this specification includes a housing, a sheet placement portion on which a sheet is placed, and a main guide that is folded back from the sheet placement portion and extends toward the outside of the housing. A photosensitive member disposed on the inner peripheral side of the main guide portion in the casing, and disposed on the inner peripheral side of the main guide portion in the casing. An exposure unit that forms a latent image and a developer image that is disposed in the casing so as to face the photoconductor via the main guide unit and that has developed the electrostatic latent image is disposed between the photoconductor and the photoconductor. A transfer portion that transfers to a sheet that passes through the transfer position; a fixing portion that is disposed downstream of the photosensitive member in the main guide portion and fixes the developer image on the sheet; and the main guide portion Arranged downstream of the fixing unit A switchback portion for reversing the traveling direction of the sheet guided by the main guide portion, and a branch from the position between the fixing portion and the switchback portion in the main guide portion, and in the main guide portion A reversing guide portion that joins a position upstream of the transfer position, and the photosensitive member and the exposure portion are disposed between the main guide portion and the reversing guide portion.

  In this image forming apparatus, a photoconductor and an exposure unit are disposed between the main guide unit and the reverse guide unit. That is, in this image forming apparatus, the reversing guide portion does not pass between the photosensitive member and the exposure portion. As a result, according to this image forming apparatus, the main guide portion that is folded back from the sheet placement portion and extends to the outside of the housing is employed, thereby reducing the size of the device and transferring the image on the sheet whose traveling direction is reversed. It can suppress that the problem in the conventional structure that cannot be formed arises.

(2) The image forming apparatus includes a developer cartridge that stores a developer, and the developer cartridge is provided so as to be movable from the inside of the housing to the outside of the housing, and among the plurality of outer surfaces of the housing, An opening for moving the developer cartridge may be formed on the outer surface closer to the reversing guide portion than the main guide portion. According to this image forming apparatus, compared with the case where the opening is formed on the outer surface closer to the main guide part than the reversing guide part, the development is performed while suppressing interference with the member disposed on the main guide part side. The movement path of the agent cartridge can be secured. In addition, since the direction in which the main guide portion extends to the outside and the opening for moving the developer cartridge are on the same side, the user can easily access the sheet and the developer cartridge.

(3) In the image forming apparatus, a part of the reversing guide portion includes a cover provided so as to be displaceable between a closed position that covers the opening and an open position that opens the opening. The agent cartridge may be configured to be movable from the opening when the cover is disposed at the open position. According to this image forming apparatus, since a part of the reversing guide part also serves as a cover, the number of parts can be reduced as compared with the case where the reversing guide part is provided independently of the cover.

(4) In the image forming apparatus, a part of the reversing guide portion may be configured by the cover and an outer surface of the developer cartridge that faces the cover. According to this image forming apparatus, since the developing cartridge constitutes a part of the reversing guide portion, the number of parts can be reduced as compared with the case where the reversing guide portion is provided independently of the developing cartridge.

(5) In the image forming apparatus, the cover is provided in the housing and is displaceably provided between a closed position that covers the opening and an open position that opens the opening of the housing. The developer cartridge may be configured to be movable from the opening when the cover is disposed at the open position. According to this image forming apparatus, by disposing the cover in the open position, a part of the reversing guide portion is opened, so that the sheet jammed in the reversing guide portion can be easily removed.

(6) In the image forming apparatus, the cover may be provided integrally with the developer cartridge, and may cover the opening when the developer cartridge is disposed in the housing. . According to this image forming apparatus, since the cover is provided integrally with the developer cartridge, the number of parts can be reduced as compared with the case where the cover and the developer cartridge are provided independently.

(7) In the image forming apparatus, the cover may also serve as a grip portion of the developer cartridge. According to this image forming apparatus, the number of parts can be reduced as compared with the case where the cover and the gripping portion are configured independently.

(8) The image forming apparatus includes an exposure control unit that controls the exposure unit, and the exposure control unit is a position between the main guide unit and the reverse guide unit, and the developer. It is good also as a structure arrange | positioned in the position which overlaps with the said exposure part in the direction which cross | intersects the arrangement direction of a cartridge and the said opening part. According to this image forming apparatus, the wiring between the exposure unit and the exposure control unit can be simplified, and the developer cartridge is moved out of the housing while suppressing interference with the exposure unit and the exposure control unit. And can be moved.

(9) The image forming apparatus includes an exposure control unit that controls the exposure unit, and the exposure control unit is configured to be connected to the developer cartridge in a direction that intersects with an alignment direction of the developer cartridge and the opening. It is good also as a structure which overlaps. According to this image forming apparatus, the developer cartridge can be moved out of the housing while suppressing the interference between the developer cartridge and the exposure control unit.

(10) In the image forming apparatus, a part of the reversing guide portion includes a cover that is displaceable between a closed position that covers the opening and an open position that opens the opening. The agent cartridge is provided so as to be movable from the opening when the cover is disposed in the open position, and the cover has an uneven shape with the reversing guide portion fixed in the housing in the closed position. It is also possible to adopt a configuration that engages with each other. According to this image forming apparatus, the cover and the reversing guide portion form a concavo-convex shape and mesh with each other, so that the sheet can be smoothly conveyed between the cover and the reversing guide portion.

(11) In the image forming apparatus, the developer cartridge may be a process unit that moves integrally with the photoconductor. According to this image forming apparatus, compared with the configuration in which the opening is formed on the outer surface close to the main guide portion, the movement path of the process unit is reduced while suppressing interference with the member arranged on the main guide portion side. Can be secured.

(12) In the image forming apparatus, the switchback unit may serve as a discharge roller that discharges the sheet conveyed from the fixing unit to the outside of the housing. According to this image forming apparatus, the number of parts can be reduced as compared with the case where the switchback unit and the discharge roller are configured independently.

1 is a side sectional view schematically showing the configuration of a printer 10 according to an embodiment (when an upper cover is closed). Side sectional view schematically showing the configuration of the printer 10 (when the upper cover is open) Side sectional view schematically showing the configuration of the printer 10A of another embodiment (when the front cover 112A is in the closed position) Side sectional view schematically showing the configuration of the printer 10A (when the front cover 112A is in the open position) View of front cover 112A viewed from the front Side sectional view which shows schematically the structure of the printer 10B of another embodiment. Side sectional view which shows roughly the structure of the printer 10C of another embodiment. Side sectional view schematically showing the configuration of the related art printer 10D

  A printer 10 according to an embodiment will be described with reference to FIGS. In the following description, the left side of each drawing is the front side F of the printer 10, the front side of the drawing is the right side R of the printer 10, and the upper side of the drawing is the upper side U of the printer 10. The printer 10 is a printer that can form a monochrome image on both sides of a sheet P using, for example, black developer (toner), and is an example of an image forming apparatus.

  As illustrated in FIG. 1, the printer 10 includes a case unit 100, and a feeder unit 200, an image forming unit 300, a switchback unit 400, a main guide unit 500, and a reverse guide are included in the case unit 100. Part 600.

  The feeder unit 200 sends out the sheet P in a direction approaching one side wall of the case unit 100, specifically, a rear wall 116 of the casing 110 described later. The main guide unit 500 guides the sheet P so that the direction of the sheet P sent out by the feeder unit 200 is changed to a direction away from the rear wall 116 of the case unit 100. Specifically, as shown in FIG. 1, the main guide portion 500 guides the sheet P so as to be folded back into a substantially C shape. The switchback unit 400 reverses the traveling direction of the sheet P guided by the main guide unit 500.

  The reversing guide unit 600 reverses the front and back of the sheet P whose traveling direction has been reversed by the switchback unit 400 and guides the sheet P to join the main guide unit 500. The image forming unit 300 forms an image on one surface of the sheet P that is fed from the feeder unit 200 and guided by the main guide unit 500, and the main guide unit 500 is again turned upside down by the reversing guide unit 600. An image is formed on the other surface of the sheet P guided by the above. Hereinafter, the direction in which the main guide unit 500 and the reverse guide unit 600 guide the sheet P, in other words, the conveyance direction of the sheet P may be simply referred to as a guide direction.

  The case unit 100 includes a housing 110 and a tray 120. The housing | casing 110 has a rectangular parallelepiped shape as a whole, and the accommodation space is formed in the inside. The upper wall of the housing 110 has a shape that is raised by one step on the way from the front end to the rear end, and a discharge port 111 for discharging the sheet P from the inside of the housing 110 to the outside is formed in this step portion. Has been. An opening 117 is formed in a portion on the front end side of the upper wall of the housing 110, and an upper cover 112 is provided so as to cover the opening 117. The upper cover 112 is supported by the housing 110 so as to be rotatable about a portion located at the rear end when the upper cover 112 is in a posture to cover the opening 117, and as shown in FIG. It can be displaced to a position and an open position that opens the opening 117 as shown in FIG. A discharge tray 113 is formed on the upper surface of the upper cover 112.

  An insertion port 114 for inserting the sheet P is formed in the lower part of the front wall 115 of the housing 110. The tray 120 can cover the front wall 115 of the housing 110, and is supported by the housing 110 so as to be rotatable about a portion positioned at the lower end when the front wall 115 is covered. It can be displaced between a closed position for closing the insertion port 114 and an open position for opening the insertion port 114 as shown in FIGS.

  The feeder unit 200 is disposed at the bottom of the case unit 100, and includes a tray 120, a pressing plate 211, a lifting mechanism 212, and a sending unit 220. The tray 120 and the pressing plate 211 are an example of a sheet placement unit, and can place one or a plurality of sheets P. The tray 120 described above is configured such that the front end side of the sheet P is placed when the tray 120 is in the open position, and covers the front wall 115 of the housing 110 when the tray 120 is in the closed position. The pressing plate 211 is supported by the housing 110 so as to be swingable about the front end, and the raising mechanism 212 pushes up the rear end side of the pressing plate 211. As a result, the rear portion of the sheet P placed on the pressing plate 211 and the leading end portion in the guide direction are lifted upward.

  The sending unit 220 is disposed above the pressing plate 211 and sends the sheet P placed on the pressing plate 211 toward the rear wall 116 side of the housing 110. Specifically, the delivery unit 220 includes a delivery roller 221, a separation roller 222, and a separation pad 223. The feeding roller 221 is disposed above the pressing plate 211 and can contact the upper surface of the leading end portion of the sheet P placed on the pressing plate 211. When the feeding roller 221 is driven to rotate, the contacting sheet P is sent out toward the rear wall 116 side. The separation roller 222 and the separation pad 223 are arranged so as to face each other at a position downstream of the sending roller 221 in the guide direction, and the sheet P sent by the sending roller 221 is separated one by one to form an image. Send to section 300.

  The image forming unit 300 is located above the sending unit 220 and at a position downstream of the sending unit 220 in the guide direction in the main guide unit 500, and the sheet P sent out by the sending unit 220. Etc. to form an image. Specifically, the image forming unit 300 includes a process cartridge 310, a transfer roller 320, an exposure unit 330, and a fixing unit 340.

  The process cartridge 310 is an example of a developer cartridge and a process unit. The process cartridge 310 is disposed at a position on the inner peripheral side of the main guide portion 500 and is movable from the inside of the housing 110 to the outside. Specifically, the process cartridge 310 is detachably attached to the housing 110, and the process cartridge 310 is moved forward and obliquely upward with the upper cover 112 opened as shown in FIG. As a result, the housing 110 is taken in and out through the opening 117 described above.

  The process cartridge 310 includes a frame 311 having an accommodating space therein, and in this frame 311, a photosensitive drum 312, a charging unit (not shown), a developing roller 313, a supply roller 314, and a developer that accommodates a developer. Agent storage chamber 315. The photosensitive drum 312 is an example of a photosensitive member. The charging unit uniformly charges the surface of the photosensitive drum 312 that is driven to rotate. The charged photosensitive drum 312 is exposed to the exposure unit 330 by being irradiated with the laser beam L, whereby an electrostatic latent image based on image data is formed on the surface of the photosensitive drum 312. The supply roller 314 and the developing roller 313 supply the developer stored in the developer storage chamber 315 to the electrostatic latent image. As a result, a developer image is formed on the surface of the photosensitive drum 312.

  The transfer roller 320 is an example of a transfer unit, and is disposed at a position on the outer peripheral side of the main guide unit 500 in the housing 110, in other words, a position facing the photosensitive drum 312 via the main guide unit 500. . The transfer roller 320 transfers the developer image formed on the photosensitive drum 312 to the sheet P that passes the transfer position X <b> 1 between the photosensitive drum 312 and the transfer roller 320. The fixing unit 340 is disposed in the housing 110 above the process cartridge 310 and at a position downstream of the transfer position X1 in the main guide unit 500 in the guide direction. A pressure roller 342 is included. When the sheet P conveyed from the transfer position X1 passes between the heating roller 341 and the pressure roller 342, the developer image is thermally fixed on the sheet P.

  Similar to the photosensitive drum 312, the exposure unit 330 is arranged on the inner peripheral side of the main guide unit 500 in the housing 110, and is not shown in the figure arranged in the rotational axis direction of the photosensitive drum 312 and the left-right direction in FIG. It has a plurality of LEDs. The exposure unit 330 is supported by the housing 110 so as to be displaceable between an exposure position shown in FIG. 1 and a retracted position shown in FIG. As shown in FIG. 1, when the upper cover 112 is in the closed position, the exposure unit 330 is positioned at an exposure position where the surface of the photosensitive drum 312 can be exposed by being irradiated with the laser light L. On the other hand, as shown in FIG. 2, when the upper cover 112 is in the open position, the exposure unit 330 is displaced from the exposure position to a retracted position above the exposure position in conjunction with the opening. Thereby, the process cartridge 310 can be taken out of the housing 110 while suppressing interference with the exposure unit 330.

  The switchback unit 400 is disposed in the housing 110 at a position above the fixing unit 340 and in the main guide unit 500 at a position downstream of the fixing unit 340 in the guide direction. The traveling direction of the sheet P conveyed by 500 is reversed. Specifically, the switchback unit 400 includes a switching member 410, a driving roller 420, and a driven roller 430. The switching member 410 can be displaced between a main feed position indicated by a one-dot chain line in FIG. 1 and a reverse feed position indicated by a solid line. The driving roller 420 and the driven roller 430 are disposed so as to face each other at a position downstream of the switching member 410 in the main guide portion 500 in the guide direction. The drive roller 420 can rotate in two directions, a forward direction and a reverse direction.

  When the sheet P is conveyed from the fixing unit 340 to the switchback unit 400, a control unit (not shown) displaces the switching member 410 to the main feed position and conveys the driving roller 420 to the discharge port 111 side. It is driven to rotate in the forward direction, clockwise in FIG. As a result, the sheet P is guided toward the discharge port 111 and conveyed toward the outside of the housing 110. Next, when the rear end of the sheet P reaches a position downstream of the switching member 410, the control unit pulls the drive roller 420 in the reverse direction to pull the sheet P into the housing 110, as shown in FIG. It is rotated counterclockwise, and the switching member 410 is displaced to the reverse feed position. As a result, the traveling direction of the sheet P is reversed, and the sheet P is guided to the inversion guide unit 600 by the switching member 410.

  The control unit rotates the drive roller 420 in the forward direction when an image is formed on one side of the sheet P during single-sided printing or when an image is formed on both sides of the sheet P during double-sided printing. Then, the entire sheet P is discharged to the discharge tray 113. At this time, the driving roller 420 and the driven roller 430 function as discharge rollers. Thus, since the switchback unit 400 also serves as a discharge roller that discharges the sheet P to the outside of the housing 110, the switchback unit 400 and the discharge roller for configuring both are configured independently. Thus, the number of parts can be reduced, and the printer can be miniaturized.

  The main guide part 500 forms a part of the main transport path R1 that is folded back from the pressing plate 211 and extends to the outside of the housing 110. Specifically, the main guide unit 500 includes a first main guide 510, a second main guide 520, and a third main guide 530, and the sheet P sent out from the pressing plate 211 is transferred to the main transport path R1. And guide it so that it is folded only once. In the main conveyance path R1, the sheet P placed on the pressing plate 211 extends to the discharge port 111 through the delivery unit 220, the transfer position X1, the fixing unit 340, and the switchback unit 400 in order. This is a substantially C-shaped path.

  The first main guide 510 is disposed between the delivery unit 220 and the transfer position X1, extends from the separation pad 223 obliquely upward to the rear side, and has a shape that bends and extends upward at a position below the transfer roller 320. . Thus, the first main guide 510 can guide the sheet P sent out by the sending unit 220 to the transfer position X1. The second main guide 520 is disposed between the transfer position X1 and the fixing unit 340 and has a pair of guide walls 521 and 522. The pair of guide walls 521 and 522 have a shape extending in the vertical direction, and are arranged at an interval in the front-rear direction. Accordingly, the second main guide 520 can guide the sheet P conveyed from the transfer position X1 to the fixing unit 340. The third main guide 530 is disposed between the fixing unit 340 and the switchback unit 400, and has a shape that is curved obliquely upward in the front side. Accordingly, the third main guide 530 can guide the sheet P conveyed from the fixing unit 340 to the discharge port 111.

  The reversing guide unit 600 branches off from a position between the fixing unit 340 and the switchback unit 400 in the main guide unit 500 and joins the main guide unit 500 at a position upstream of the transfer position X1 in the guide direction. . Specifically, the reversing guide unit 600 includes a first reversing guide 610 and a second reversing guide 620, and the sheet P whose traveling direction is reversed by the switchback unit 400 is moved along the reversing conveyance path R2. To guide. The reverse conveyance path R2 is a path extending from the switchback unit 400 to the junction position X2 with the main conveyance path R1 through the vicinity of the upper cover 112 and the vicinity of the front wall 115 of the housing 110 in order.

  The first reversing guide 610 is disposed between the switchback unit 400 and the front wall 115 of the housing 110 in the reversing conveyance path R <b> 2, and includes a first outer guide wall 611 and a first inner guide wall 612. The first outer guide wall 611 and the first inner guide wall 612 extend forward from the vicinity of the switchback portion 400 and have a shape curved downward before the front wall 115. The first inner guide wall 612 is disposed below the first outer guide wall 611, in other words, closer to the process cartridge 310. Accordingly, the first reversing guide 610 can guide the sheet P whose traveling direction has been reversed by the switchback unit 400 to the second reversing guide 620. The first reversing guide 610 is fixed to the upper cover 112, and integrally opens and closes together with the upper cover 112 (see FIGS. 1 and 2).

  The first reversing guide 610 is provided with a conveying roller 613. The conveying roller 613 is gear-coupled to a driving mechanism (not shown) when the upper cover 112 is in the closed position, and is rotated to drive the sheet P. Can be transported. On the other hand, when the upper cover 112 is in the open position, the transport roller 613 is disengaged from the gear mechanism and can idle. Thereby, when the sheet P is jammed in the first reversing guide 610, the jammed sheet P can be easily removed by opening the upper cover 112.

  The second reversing guide 620 is disposed between the first reversing guide 610 and the merge position X2 in the reversing conveyance path R2, and includes a second outer guide wall 621 and a second inner guide wall 622. The second outer guide wall 621 extends downward from a position facing the end portion of the first outer guide wall 611 and curves backward so as to be parallel to the outer surface shape of the frame 311 of the process cartridge 310. It has a shape extending to the front of the position X2. The second inner guide wall 622 is disposed between the frame 311 and the second outer guide wall 621, and has a shape extending from the vicinity of the lower front side of the frame 311 to the front of the joining position X2 toward the rear. Accordingly, the second reversing guide 620 can guide the sheet P conveyed from the first reversing guide 610 toward the joining position X2.

  Here, the second inner guide wall 622 does not exist between the second outer guide wall 621 and the front surface 316 of the frame 311, and the second outer guide wall 621 and the front surface 316 of the frame 311 directly face each other. doing. That is, a part of the reversing guide portion 600 is constituted by the outer surface of the process cartridge 310. As a result, compared to the case where the entire reversing guide unit 600 is provided independently of the outer surface of the process cartridge 310, the number of parts for constituting the reversing guide unit 600 can be reduced, and the entire printer 10 can be reduced in size. Can be planned.

  In the printer 10 of the present embodiment, a photosensitive drum 312 and an exposure unit 330 are disposed between the main guide unit 500 and the reverse guide unit 600. That is, in the printer 10, the reversing guide unit 600 does not pass between the photosensitive drum 312 and the exposure unit 330. Thus, according to the present embodiment, the main guide portion 500 that is folded back from the pressing plate 211 and extends to the outside of the housing 110 is employed to reduce the size of the apparatus, and the image is displayed on the sheet P whose traveling direction is reversed. It is possible to suppress the occurrence of a problem in the conventional configuration that cannot be formed.

  3 to 5 show a printer 10A according to another embodiment. A configuration that is common to the printer 10 of the above-described embodiment shown in FIG. 1 or that differs only in position and size is assigned the same reference numeral as in FIG. In addition, about the structure different from the printer 10, the code | symbol which added alphabet "A" to the end shall be attached | subjected. The configuration different from the printer 10 has the same kind of function as the configuration of the printer 10 of FIG. 1 and corresponds to each other, and the same numerals as those of the printer 10 are appended with a letter with an alphabet “A” added to the end. To do.

  As shown in FIGS. 3 and 4, the case portion 100 </ b> A includes a housing 110 </ b> A and a front cover 120. The front wall 115 of the housing 110A is formed with an opening 117A for moving a process cartridge 310A described later. As described above, the opening 117A is formed on the outer surface closer to the reversal guide portion 600A than the main guide portion 500A among the plurality of outer surfaces of the housing 110A, that is, the front wall 115. Therefore, compared with the case where the opening 117A is formed on the rear wall 116 closer to the main guide portion 500A than the reversing guide portion 600A, interference with the transfer roller 320 and the like disposed on the main guide portion 500A side is suppressed. However, the movement path of the process cartridge 310A can be secured. The opening 117A is disposed on the same side as the sheet P discharging direction, that is, on the front side of the housing 110A. As a result, the user can easily access the sheet P and the process cartridge 310A.

  The main guide portion 500A forms a part of the main transport path R1A that is folded back from the pressing plate 211 and extends to the outside of the housing 110A. Specifically, the main guide portion 500A includes a first main guide 510, a second main guide 520A, and a third main guide 530A. The second main guide 520A is disposed between the transfer position X1 and the fixing unit 340, and has a pair of guide walls 521A and 522A. The pair of guide walls 521A and 522A have a shape extending in the vertical direction, and are arranged at intervals in the front-rear direction. The third main guide 530A is disposed between the fixing unit 340 and the switchback unit 400, and includes a pair of guide walls 531A and 532A. The pair of guide walls 531A and 532A have a shape that is curved obliquely upward in the front side, and are arranged at an interval from each other.

  The process cartridge 310A is arranged at a position on the inner peripheral side of the main guide portion 500A, and is movable from the inside of the housing 110A to the outside. The process cartridge 310A has a frame 311A having an accommodating space inside, and the frame 311A has the same configuration as the process cartridge 310 shown in FIG. A front cover 112A is integrally provided on the front surface 316A side of the process cartridge 310A.

  The front cover 112A is an example of a cover, has a size corresponding to the opening 117A, and is disposed at a closed position that covers the opening 117A when the process cartridge 310A is disposed in the housing 110A. (See FIG. 3). Further, the front cover 112A can be horizontally moved integrally with the process cartridge 310A to be displaced to an open position where the opening 117A is opened (see FIG. 4). Thereby, compared with the case where front cover 112A and process cartridge 310A are provided independently, the number of parts for constituting both can be reduced.

  Further, an internal path through which the sheet P can pass is formed in the vertical direction between the front cover 112A and the front surface 316A of the frame 311A. Further, the front cover 112A also serves as a grip portion of the process cartridge 310A. Specifically, as shown in FIG. 5, one or a plurality of through holes 118A into which human fingers can be inserted are formed on the outer surface of the front cover 112A. Thus, the process cartridge 310A can be easily taken in and out of the housing 110A by putting a finger into the through hole 118A and the like and holding the front cover 112A. Moreover, compared with the case where front cover 112A and a holding part are comprised independently, the number of parts for comprising both can be reduced.

  The exposure unit 330 is disposed on the inner peripheral side of the main guide unit 500A in the housing 110A. With respect to the housing 110A, an exposure position indicated by a solid line in FIG. 3 and a retracted position indicated by a solid line in FIG. It is supported so that it can be displaced. The exposure position is a position where the exposure unit 330 and the process cartridge 310A overlap when viewed from the moving direction of the process cartridge 310A toward the opening 117A, and the standby position is the exposure unit 330 and the process cartridge 310A when viewed from the moving direction. Are positions that do not overlap with each other, that is, positions that are further from the process cartridge 310A than the exposure position.

  As shown in FIG. 3, when the front cover 112 </ b> A is in the closed position, when the exposure unit 330 receives an exposure start instruction from the control unit, the exposure unit 330 is displaced from the standby position to the exposure position, and the laser light L is transferred to the photosensitive drum 312. The surface can be irradiated for exposure. On the other hand, when the exposure unit 330 receives an exposure end instruction from the control unit, the exposure unit 330 returns to the standby position. Thus, when exposure is stopped, the process cartridge 310A can be taken out of the housing 110A while suppressing interference with the exposure unit 330.

  An exposure control board 331A is connected to the exposure unit 330 via a signal line (not shown). The exposure control board 331A is an example of an exposure control unit, and controls the lighting operation of the exposure unit 330 based on an instruction from the control unit. The exposure control substrate 331A is located between the main guide portion 500A and the reversal guide portion 600A and overlaps the process cartridge 310A in the direction (vertical direction) intersecting the moving direction of the process cartridge 310A, specifically, The cartridge is disposed at a position above the process cartridge 310A. In other words, the exposure control substrate 331A is arranged at a position aligned with the process cartridge 310A in a direction crossing the moving direction or a position not overlapping the process cartridge 310A when viewed from the moving direction. Thereby, the process cartridge 310A can be moved out of the housing 110A while suppressing the interference between the process cartridge 310A and the exposure control substrate 331A.

  Further, the exposure control board 331A is disposed at a position overlapping the exposure unit 330 in a direction crossing the moving direction of the process cartridge 310A. Specifically, the exposure control substrate 331A is disposed at a position facing the process cartridge 310A via the exposure unit 330 in a direction crossing the moving direction. Thereby, since the exposure part 330 and the exposure control board | substrate 331A are arrange | positioned in the comparatively near position, wiring, such as a signal wire | line and a harness, can be simplified.

  The reversing guide portion 600A branches from a position between the fixing portion 340 and the switchback portion 400 in the main guide portion 500A, and joins the joining position X2 in the main guide portion 500A. Specifically, the reversing guide portion 600A includes a first reversing guide 610A, a front cover 112A, a process cartridge 310A, and a second reversing guide 620A.

  The first reversing guide 610A is disposed between the switchback unit 400 and the front cover 112A in the reversing conveyance path R2A, and includes a first outer guide wall 611A and a first inner guide wall 612A. The first outer guide wall 611A and the first inner guide wall 612A are curved from the vicinity of the switchback portion 400 while being spaced apart from each other, and have a shape extending to the vicinity of the upper end of the front cover 112A at the closed position. Thereby, the first reversing guide 610A can guide the sheet P whose traveling direction is reversed by the switchback unit 400 to the internal path between the front cover 112A and the front surface 316A of the frame 311A.

  The sheet P guided by the first reversing guide 610A is guided to the second reversing guide 620A by the front cover 112A and the front surface 316A of the frame 311A. As described above, since a part of the reversing guide portion 600A also serves as the front cover 112A, the number of parts for configuring both is reduced compared to the case where the reversing guide portion 600A is provided independently of the front cover 112A. be able to. Further, since the process cartridge 310A constitutes a part of the reversing guide portion 600A, the number of parts for constituting both can be reduced as compared with the case where the reversing guide portion 600A is provided independently of the process cartridge 310A. Can do.

  Here, as shown in FIG. 5, the upper end portion 119A of the front cover 112A and the corresponding first outer guide wall 611A and the lower end 614A of the front wall 115 have an uneven shape and are arranged so as to mesh with each other. ing. Accordingly, the sheet P can be smoothly guided between the front cover 112A and the first outer guide wall 611A.

  The second reversing guide 620A is disposed between the front cover 112A and the joining position X2 in the reversing conveyance path R2A, and is parallel to the outer surface shape of the frame 311A from the vicinity of the lower end of the front cover 112A at the closed position. Thus, it has a shape curved toward the front of the merging position X2 while extending backward. Thus, the second reversing guide 620A can guide the sheet P conveyed from the internal path toward the joining position X2 between the second reversing guide 620A and the outer surface of the frame 311A of the process cartridge 310A.

  In the printer 10A of the present embodiment, a photosensitive drum 312 and an exposure unit 330 are disposed between the main guide unit 500A and the reverse guide unit 600A. As a result, according to the present embodiment, the main guide portion 500A that is folded back from the pressing plate 211 and extends to the outside of the housing 110A is used to reduce the size of the apparatus, and the image is displayed on the sheet P whose traveling direction is reversed. It is possible to suppress the occurrence of a problem in the conventional configuration that cannot be formed.

  FIG. 6 shows a printer 10B according to another embodiment. Configurations common to the printers 10 and 10A of the above-described embodiment shown in FIGS. 1 and 3 or configurations that differ only in position and size are assigned the same reference numerals as the printers 10 and 10A, and descriptions thereof are omitted. Will be described next. Note that components different from those of the printers 10 and 10A are denoted by reference numerals with an alphabet “B” added to the end. In the case where the configurations different from the printers 10 and 10A have the same functions as the configurations of the printers 10 and 10A, etc., and correspond to each other, the same numerals as those of the printers 10 and 10A are suffixed with an alphabet “B”. It shall be attached.

  As shown in FIG. 6, the case portion 100B includes a housing 110B and a front cover 120. An opening 117B for moving a process cartridge 310B, which will be described later, is formed in the front wall 115 of the housing 110B. As described above, the opening 117B is formed on the outer surface closer to the reversal guide portion 600B than the main guide portion 500A among the plurality of outer surfaces of the housing 110B, that is, the front wall 115. Therefore, compared with the case where the opening 117B is formed on the rear wall 116 closer to the main guide portion 500A than the reversing guide portion 600B, interference with the transfer roller 320 and the like disposed on the main guide portion 500A side is suppressed. In addition, the movement path of the process cartridge 310B can be secured.

  The casing 110B is provided with a front cover 112B so as to cover the opening 117B. The front cover 112B is supported by the housing 110B so as to be rotatable about a portion positioned at the lower end when the posture covers the opening 117B, and closes the opening 117B as shown by a solid line in FIG. It can be displaced to a closed position and an open position that opens the opening 117B as indicated by a two-dot chain line. By setting the front cover 112B to the open position, the process cartridge 310B can be taken out of the housing 110B.

  The process cartridge 310B is disposed at a position on the inner peripheral side of the main guide portion 500A, and is movable from the inside of the housing 110B to the outside. The process cartridge 310B has a frame 311B having an accommodation space inside, and the frame 311B has the same configuration as the process cartridge 310 shown in FIG. The front surface 316B of the process cartridge 310B is opposed to be parallel to the inner surface of the front cover 112B at the closed position. In addition, since there is a gap between the front cover 112B and the front surface 316B of the frame 311B, an internal path through which the sheet P can pass is formed in the vertical direction. As in the case of the front cover 112A in FIG. 5, a through hole or a recess (not shown) is formed in the protruding portion 317B protruding upward from the front surface 316B of the frame 311B, so that the protruding portion 317B holds the process cartridge 310B. It may also serve as a part.

  The exposure unit 330B is fixedly disposed on the inner peripheral side of the main guide unit 500A in the housing 110B, and includes a laser light emitting unit, a polygon mirror, a lens, and a reflecting mirror (not shown). The exposure unit 330B is disposed at a position where the process cartridge 310B overlaps the process cartridge 310A in a direction intersecting the moving direction toward the opening 117B, in other words, a position where the process cartridge 310B does not overlap the process cartridge 310A when viewed from the moving direction. Has been. Thereby, the process cartridge 310B can be taken out of the housing 110B while suppressing interference with the exposure unit 330B.

  The reversing guide portion 600B branches from the position between the fixing portion 340 and the switchback portion 400 in the main guide portion 500A, and joins the joining position X2 in the main guide portion 500A. Specifically, the reverse guide portion 600B includes a first reverse guide 610B, a front cover 112B, a process cartridge 310B, and a second reverse guide 620B.

  The first reversing guide 610B is disposed between the switchback unit 400 and the front cover 112B in the reversing transport path R2B, and includes a first outer guide wall 611B and a first inner guide wall 612B. The first outer guide wall 611B and the first inner guide wall 612B are curved from the vicinity of the switchback portion 400 while being spaced apart from each other, and have a shape extending to the vicinity of the upper end of the front cover 112B in the closed position. . Accordingly, the first reversing guide 610B can guide the sheet P whose traveling direction is reversed by the switchback unit 400 to an internal path between the front cover 112B and the front surface 316B of the frame 311B.

  The sheet P guided by the first reversing guide 610B is guided to the second reversing guide 620B by the front cover 112B and the front surface 316B of the frame 311B. In this way, since a part of the reversing guide portion 600B also serves as the front cover 112B, the number of parts for configuring both is reduced compared to the case where the reversing guide portion 600B is provided independently of the front cover 112B. be able to. Further, since the process cartridge 310B constitutes a part of the reversing guide portion 600B, the number of parts for constituting both can be reduced as compared with the case where the reversing guide portion 600B is provided independently of the process cartridge 310B. Can do.

  Similar to the configuration shown in FIG. 5, the upper end portions of the front cover 112B and the protruding portion 317B and the corresponding first outer guide wall 611B and the lower end portion of the front wall 115 are made uneven so as to engage with each other. (Not shown). Accordingly, the sheet P can be smoothly guided between the first outer guide wall 611B and the front cover 112B, or between the first inner guide wall 612B and the protruding portion 317B.

  The second reversing guide 620B is disposed between the front cover 112B and the joining position X2 in the reversing conveyance path R2B, and is parallel to the outer surface shape of the frame 311B from the vicinity of the lower end of the front cover 112B when in the closed position. Thus, it has a shape curved toward the front of the merging position X2 while extending backward. Accordingly, the second reversing guide 620B can guide the sheet P conveyed from the internal path toward the joining position X2 between the second reversing guide 620B and the outer surface of the frame 311B of the process cartridge 310B.

  In the printer 10B of the present embodiment, the photosensitive drum 312 and the exposure unit 330B are disposed between the main guide unit 500A and the reverse guide unit 600B. As a result, according to the present embodiment, the main guide portion 500A that is folded back from the pressing plate 211 and extends to the outside of the housing 110B is employed to reduce the size of the apparatus, and the image is displayed on the sheet P whose traveling direction is reversed. It is possible to suppress the occurrence of a problem in the conventional configuration that cannot be formed. Further, by disposing the front cover 112B at the open position, a part of the reversing guide portion 600B is opened, so that the sheet P jammed in the reversing guide portion 600B can be easily removed.

  FIG. 7 shows a printer 10C according to another embodiment. The configurations common to the printers 10, 10 </ b> A, 10 </ b> B of the above-described embodiment shown in FIG. 1 to FIG. Next, a different configuration will be described. Note that components different from the printers 10, 10 </ b> A, and 10 </ b> B are denoted by a symbol with an alphabetical “C” added at the end. When the configurations different from the printers 10, 10A, and 10B have the same functions as the configurations of the printers 10, 10A, and 10B and correspond to each other, the alphabet “C” is added to the end of the same numbers as the printers 10, 10A, and 10B. "Is added.

  As illustrated in FIG. 7, the case unit 100 </ b> C includes a housing 110 </ b> C and a front cover 120. The housing 110C has substantially the same shape as the housing 110B shown in FIG. An opening 117C for moving a process cartridge 310C described later is formed in the front wall 115 of the housing 110C. Thus, the opening 117C is formed in the front wall 115 closer to the inversion guide portion 600C than the main guide portion 500A among the plurality of outer surfaces of the housing 110C. Therefore, compared with the case where the opening 117C is formed on the rear wall 116 closer to the main guide portion 500A than the reversing guide portion 600C, interference with the transfer roller 320 and the like disposed on the main guide portion 500A side is suppressed. In addition, the movement path of the process cartridge 310C can be secured.

  The housing 110C is provided with a front cover 112C so as to cover the opening 117C. The front cover 112C is supported by the housing 110C so as to be rotatable about a portion positioned at the lower end when the opening 117C is covered, and closes the opening 117C as indicated by a solid line in FIG. It can be displaced to a closed position and an open position that opens the opening 117C as indicated by a two-dot chain line. By setting the front cover 112C to the open position, the process cartridge 310C can be taken out of the housing 110C. Further, an internal path 700 through which the sheet P can pass is formed in the front cover 112C in the vertical direction.

  The process cartridge 310C is disposed at a position on the inner peripheral side of the main guide portion 500A, and is movable from the inside of the housing 110C to the outside. The process cartridge 310C has a frame 311C having an accommodation space inside, and the frame 311C has the same configuration as the process cartridge 310 shown in FIG. The front surface 316C of the process cartridge 310C faces the inner surface of the front cover 112C when in the closed position.

  The reversing guide portion 600C branches from a position between the fixing portion 340 and the switchback portion 400 in the main guide portion 500A, and joins the joining position X2 in the main guide portion 500A. Specifically, the reversing guide portion 600C includes a first reversing guide 610B, a front cover 112C, and a second reversing guide 620B.

  The sheet P guided by the first reversing guide 610B is guided to the second reversing guide 620B by the internal path 700 of the front cover 112C. In this way, since a part of the reversing guide portion 600C also serves as the front cover 112C, the number of parts for constituting both is reduced compared to the case where the reversing guide portion 600C is provided independently of the front cover 112C. be able to.

  In the printer 10C of the present embodiment, the photosensitive drum 312 and the exposure unit 330B are disposed between the main guide unit 500A and the reverse guide unit 600C. As a result, according to the present embodiment, the main guide portion 500A that is folded back from the pressing plate 211 and extends to the outside of the housing 110C is used to reduce the size of the apparatus, and the image is displayed on the sheet P whose traveling direction is reversed. It is possible to suppress the occurrence of a problem in the conventional configuration that cannot be formed. In addition, by disposing the front cover 112C in the open position, the reversing guide portion 600C is divided in the middle, so that the sheet P jammed in the reversing guide portion 600C can be easily removed.

  FIG. 8 shows a related art printer 10D. Configurations common to the printers 10 and 10A of the above-described embodiment shown in FIGS. 1 to 6 or configurations that differ only in position and size are assigned the same reference numerals as those of the printers 10 and 10A, and descriptions thereof are omitted. Will be described next. Note that components different from those of the printers 10 and 10A are denoted by reference numerals with an alphabet “D” added to the end. In the case where the configurations different from the printers 10 and 10A have the same type of functions as the configurations of the printers 10 and 10A, etc., and correspond to each other, the same numerals as those of the printers 10 and 10A are suffixed with an alphabet “D”. It shall be attached.

  The case unit 100D includes a housing 110D and a front cover 120. The casing 110D has a rectangular parallelepiped shape as a whole, and an accommodation space is formed inside. The upper wall of the housing 110D has a shape that is raised by one step on the way from the front end to the rear end, and a discharge port 111 for discharging the sheet P from the inside of the housing 110 to the outside is formed in the step portion. Has been. An opening 117D is formed in a portion on the front end side of the upper wall of the housing 110, and an upper cover 112D is provided so as to cover the opening 117D. The upper cover 112D is supported by the housing 110D so as to be rotatable around a portion located at the rear end when the upper cover 112D is in a posture to cover the opening 117D, and closes the opening 117D as shown by a solid line in FIG. It can be displaced to a closed position where it is opened and an open position where the opening 117D is opened as indicated by a two-dot chain line. A discharge tray 113D is formed on the upper surface of the upper cover 112D.

  The process cartridge 310D is disposed at a position on the inner peripheral side of the main guide portion 500A and is movable from the inside of the housing 110D to the outside. Specifically, the process cartridge 310D is detachably attached to the housing 110D, and the opening 117D is moved by moving the process cartridge 310D obliquely upward in the forward direction with the upper cover 112D in the open position. Through the housing 110D. The process cartridge 310D has a frame 311D having an accommodation space inside, and the frame 311D has the same configuration as the process cartridge 310 shown in FIG.

  The exposure unit 330D is fixedly disposed outside the region surrounded by the main guide unit 500A and the reversing guide unit 600D, and includes a laser light emitting unit, a polygon mirror, a lens, and a reflecting mirror (not shown). Specifically, the exposure unit 330D does not overlap with the process cartridge 310D in a position where the process cartridge 310D overlaps with the process cartridge 310D in a direction intersecting the moving direction toward the opening 117D, in other words, when viewed from the moving direction. Placed in position. Thus, the process cartridge 310D can be taken out of the housing 110D while suppressing interference with the exposure unit 330D.

  The reversing guide portion 600D branches from a position between the fixing portion 340 and the switchback portion 400 in the main guide portion 500A, and joins the joining position X2 in the main guide portion 500A. Specifically, the reversing guide unit 600D includes a movable guide unit 601D, a first reversing guide 610D, and a second reversing guide 620D, and reverses the sheet P whose traveling direction is reversed by the switchback unit 400. Guide along the transport path R2D. The reverse conveyance path R2D traverses the optical path of the laser light L between the process cartridge 310D and the exposure unit 330D from the switchback unit 400, travels below the exposure unit 330D, and reverses the direction below the exposure unit 330D. This is a path that is folded back so as to pass through the lower part of the process cartridge 310D to the joining position X2 with the main transport path R1.

  The movable guide portion 601D is configured to move in conjunction with the displacement of the upper cover 112D. Specifically, when the upper cover 112D is in the closed position, the movable guide unit 601D is disposed between the switchback unit 400 and the optical path of the laser beam L in the reverse conveyance path R2D as shown by a solid line in FIG. In addition, it has a shape that extends downward from the vicinity of the switchback portion 400 while curving backward. Thereby, the movable guide part 601D can guide the sheet P whose traveling direction is reversed by the switchback part 400 to the first reversing guide 610D. When the upper cover 112D is displaced to the open / close position, the movable guide portion 601D moves upward together with the upper cover 112D, so that the process cartridge 310D can be taken in and out of the housing 110D.

  The first inversion guide 610D is disposed between the optical path of the laser light L and the front wall 115 of the housing 110D in the inversion conveyance path R2B, and includes a first outer guide wall 611D and a first inner guide wall 612D. . The first outer guide wall 611D and the first inner guide wall 612D are curved from the vicinity of the optical path of the laser light L while being spaced apart from each other, and have a shape extending to the vicinity of the front wall 115. Accordingly, the first reversing guide 610D can guide the sheet P whose traveling direction is reversed by the switchback unit 400 to the second reversing guide 620.

  The second reversing guide 620D is disposed between the first reversing guide 610D and the joining position X2 in the reversing conveyance path R2D, and includes a second outer guide wall 621D and a second inner guide wall 622D. The second outer guide wall 621D has a shape that is curved in a substantially C shape from a position facing the end portion of the first outer guide wall 611D, faces the rear wall 116, and extends to the front of the merging position X2. The second inner guide wall 622D is disposed between the frame 311D and the second outer guide wall 621D, and has a shape extending from near the lower front side of the frame 311D toward the rear wall 116 up to the junction position X2. Have. Accordingly, the second reversing guide 620D can guide the sheet P conveyed from the first reversing guide 610D toward the joining position X2.

  With this configuration, in this related technique, the length of the conveyance path of the sheet P from the vicinity of the optical path of the laser beam L to the transfer position X1 via the first inversion guide 610D and the second inversion guide 620D is reduced. The length of the long side of the maximum size sheet P that can be printed by the printer 10D is longer. For this reason, it can suppress that the problem in the conventional structure that an image cannot be formed in the sheet | seat P in which the advancing direction was reversed occurred.

  The technology disclosed in the present specification is not limited to the embodiments described with reference to the above description and drawings, and includes, for example, the following various aspects.

  In the above-described embodiment, the monochrome printer 10 or the like has been described as an example of the image forming apparatus. However, the image forming apparatus is not limited thereto, and may be an image forming apparatus capable of color printing. The image forming apparatus is not limited to a single printer, and may be a copier, a facsimile machine, a multi-function machine, or the like. The present invention is also applicable to these image forming apparatuses.

  In the above embodiment, the tray 120 and the pressing plate 211 are given as an example of the sheet placement unit. However, the present invention is not limited to this, and the entire sheet placement unit may be housed in the housing 110 or the like, and is not limited to the tray type, but a cassette type that can be inserted into the insertion port 114 of the housing 110 or the like. It may be. For example, a printer without the tray 120 may be used. In this case, for example, the front end side of the sheet P may be placed on the pressing plate 211 and the rear end side may be supported by a floor, a desk, or the like.

In the above-described embodiment, the process cartridge 310 and the like are described as an example of the developer cartridge and the process unit. However, the present invention is not limited to this, and the developer cartridge or the like may be configured such that the transfer roller 320 is also housed in the frame 311 of the process cartridge 310. The structure except at least one may be sufficient. In short, the developer cartridge only needs to accommodate at least the developer.
When the image forming apparatus has a configuration capable of forming a color image, the current agent cartridge or the like may be a drawer that is a unit that accommodates a plurality of colorant accommodating cartridges.

  Further, the process cartridge 310 or the like may be configured to protrude from the housing 110 at least partially without being detached from the housing 110 or the like. In short, the developer cartridge only needs to be movable from the inside of the housing to the outside of the housing.

  1 and 2, the conveyance roller 613 may be provided only in the second reversing guide 620, or may be provided in both the first reversing guide 610 and the second reversing guide 620.

  For example, in the printer 10 of FIG. 1, the ends facing each other in the cuts of the reversing guide portions 600 to 600 </ b> D, such as the facing portions of the first reversing guide 610 and the second reversing guide 620, are formed in an uneven shape. You may make it mesh. Thereby, the sheet | seat P can be smoothly guided in each break of the inversion guide parts 600-600D.

  The exposure unit 330 of the printers 10 and 10A may be of a polygon scanning exposure type, and the exposure unit 330B of the printers 10B and 10C may be of an LED exposure type. Further, for the printers 10 to 10C, the process cartridge 310 and the exposure unit 330 may be arranged in the horizontal direction between the main guide unit 500 and the reverse guide unit 600.

  10 to 10D: Printer 110 to 110D: Housing 112A to 112D: Cover 117 to 117D: Opening 120: Tray 211: Pressing plate 310 to 310D: Process cartridge 312: Photosensitive drum 320: Transfer roller 330, 330B, 330D: Exposure Part 331A: Exposure control board 340: Fixing part 400: Switchback part 500-500D: Main guide part 600-600D: Inversion guide part L: Laser light P: Sheet X1: Transfer position

Claims (11)

A housing,
A sheet placing portion provided at a lower portion of the housing and on which a sheet is placed;
A main guide portion extending upward from the sheet placement portion and extending outward from the housing;
A photoconductor disposed on the inner peripheral side of the main guide portion in the housing;
An exposure unit that is disposed on the inner peripheral side of the main guide unit in the housing and forms an electrostatic latent image by irradiating the photoconductor with light;
In the housing, the developer image, which is arranged to face the photoconductor through the main guide portion and has the electrostatic latent image developed, is transferred to a sheet that passes through a transfer position between the photoconductor and the photoconductor. A transfer section
A fixing unit disposed downstream of the photoconductor in the main guide unit and fixing the developer image on the sheet;
A switchback unit that is disposed downstream of the fixing unit in the main guide unit and reverses the traveling direction of the sheet guided by the main guide unit;
A reversing guide section that branches from a position between the fixing section and the switchback section in the main guide section and merges with a position upstream of the transfer position in the main guide section;
A developer cartridge for containing the developer;
An exposure control unit for controlling the exposure unit;
With
The photoconductor, the exposure unit, the developer cartridge, and the exposure control unit are disposed between the main guide unit and the reverse guide unit ,
The exposure control unit is disposed between the exposure unit and the fixing unit in the alignment direction of the developer cartridge and the sheet placement unit .
Image forming apparatus. The image forming apparatus according to claim 1,
The developer cartridge is movably provided from the inside of the housing to the outside of the housing,
An image forming apparatus in which an opening for moving the developer cartridge is formed on an outer surface closer to the reversing guide portion than the main guide portion among a plurality of outer surfaces of the housing. The image forming apparatus according to claim 2,
A part of the reversing guide part is composed of a cover that is displaceably provided at a closed position that covers the opening and an open position that opens the opening,
The image forming apparatus, wherein the developer cartridge is provided to be movable from the opening when the cover is disposed at the open position. The image forming apparatus according to claim 3, wherein
A part of the reversing guide part is constituted by the cover and an outer surface of the developer cartridge facing the cover, of the outer surface of the developer cartridge. The image forming apparatus according to claim 4,
The cover is provided in the housing and is displaceably provided at a closed position that covers the opening and an open position that opens the opening of the housing.
The image forming apparatus, wherein the developer cartridge is provided to be movable from the opening when the cover is disposed at the open position. The image forming apparatus according to claim 4,
The image forming apparatus, wherein the cover is provided integrally with the developer cartridge and covers the opening when the developer cartridge is disposed in the housing. The image forming apparatus according to claim 6,
The image forming apparatus, wherein the cover also serves as a grip portion of the developer cartridge. An image forming apparatus according to any one of claims 3 to 5 ,
The image forming apparatus according to claim 1, wherein the cover engages with each other in an uneven shape with a reversing guide portion fixed in the housing in the closed position. An image forming apparatus according to any one of claims 1 to 8,
The image forming apparatus, wherein the developer cartridge is a process unit that moves integrally with the photoconductor. An image forming apparatus according to any one of claims 1 to 9 , wherein
The switchback unit is an image forming apparatus that also serves as a discharge roller that discharges the sheet conveyed from the fixing unit to the outside of the casing.   A housing,
  A sheet placing portion provided at a lower portion of the housing and on which a sheet is placed;
  A main guide portion extending upward from the sheet placement portion and extending outward from the housing;
  A photoconductor disposed on the inner peripheral side of the main guide portion in the housing;
  An exposure unit that is disposed on the inner peripheral side of the main guide unit in the housing and forms an electrostatic latent image by irradiating the photoconductor with light;
  In the housing, the developer image, which is arranged to face the photoconductor through the main guide portion and has the electrostatic latent image developed, is transferred to a sheet that passes through a transfer position between the photoconductor and the photoconductor. A transfer section
  A fixing unit disposed downstream of the photoconductor in the main guide unit and fixing the developer image on the sheet;
  A switchback unit that is disposed downstream of the fixing unit in the main guide unit and reverses the traveling direction of the sheet guided by the main guide unit;
  A reversing guide section that branches from a position between the fixing section and the switchback section in the main guide section and merges with a position upstream of the transfer position in the main guide section;
  A developer cartridge containing the developer;
  An exposure control unit for controlling the exposure unit;
With
  The photoconductor, the exposure unit, the developer cartridge, and the exposure control unit are disposed between the main guide unit and the reverse guide unit, and the sheet placement unit and the development unit from below. It is arranged in the order of the agent cartridge, the exposure unit, the exposure control unit,
  The sheet placement unit, the developer cartridge, the exposure unit, and the exposure control unit overlap each other when viewed in the vertical direction.
  Image forming apparatus.

Images