JP5358493B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus including an image carrier and a developing device.

  In an image forming apparatus using an electrophotographic system such as a copying machine, a printer, or a FAX, a powdered developer (hereinafter referred to as toner) is mainly used. Then, an electrostatic latent image formed by charging and exposure on an image carrier such as a photosensitive drum is visualized by toner in the developing device, and the toner image is transferred onto a recording medium, followed by fixing processing. An image forming process to be performed is generally performed. In such an image forming apparatus, a duct is provided in the developing device, and air in the developing device is discharged, thereby avoiding cooling in the developing device and scattering of toner in the developing device.

  For example, in Patent Document 1, a developing roller and a stirring roller are provided in a developing tank, a through cylinder that penetrates the developing tank is provided in the axial direction, and the inside of the through tank is used as a cold air passage to cool the inside of the developing tank. Techniques to do this are disclosed.

  Further, Patent Document 2 includes a toner carrier covering member that covers a part of the outer peripheral surface of the toner carrier via a gap, and a suction mechanism that forcibly sucks air in the gap, whereby the development process is performed. A technique for preventing toner scattering and heat generation even when the speed is increased is disclosed.

JP-A-4-109267 JP 2002-278268 A

  Here, some conventional image forming apparatuses have a developing device that can be attached to and detached from the apparatus main body. After the developing apparatus is supported by a support portion provided in the apparatus main body, the developing device is attached together with the support portion. By rotating, the developing roller disposed in the developing device may be disposed at a developing position where toner can be supplied to the photosensitive drum.

  FIG. 10 and FIG. 11 show the state in which the developing device is mounted on the apparatus main body in this way. FIG. 10 is a partial perspective view showing a state in which the developing device is arranged at the developing position in the conventional image forming apparatus, and FIG. 11 is a partial perspective view showing a state in which the developing device is arranged at the attaching / detaching position.

  As shown in FIG. 10, a first support frame 61 capable of supporting a developing unit (developing device) 8 is disposed in the apparatus main body. The first support frame 61 is disposed along a direction perpendicular to the conveyance direction of the sheet on which an image is formed, and the first support shaft extends from the upper end of both longitudinal walls of the first support frame 61 toward both outer sides in the longitudinal direction. 61a protrudes. The first support shaft 61a is rotatably inserted into an engagement hole (not shown) provided in the apparatus main body, whereby the first support frame 61 is connected to the first support shaft 61a, that is, the first rotation shaft. It is supported so as to be rotatable in the paper transport direction with X as a fulcrum.

  Further, as shown in FIG. 10, the first support frame 61 has a position where a developing roller (not shown here) provided in the developing unit 8 can supply toner to a photosensitive drum (not shown here). The developing unit 8 can be rotated between a developing position) and a position below the developing position where the developing unit 8 can be attached to and detached from the first support frame 61 (attachment / detachment position). Further, the developing unit 8 is attached to and detached from the first support frame 61 by being inserted into and pulled out from the first support frame 61 along the longitudinal direction.

  In addition, a cylindrical first relay portion 61b penetrating through both end portions in the longitudinal direction is provided at a position different from the first support shaft 61a in one longitudinal end portion (for example, the rear side end portion) of the first support frame 61. Is formed. The first opening end 61ba on the developing unit 8 side with respect to the first support frame 61 in the first relay portion 61b is formed of a duct provided in the developing unit 8, and an exhaust unit 47 that discharges the air in the developing unit 8 to the outside. The first opening 47a is fitted.

  Thereby, when the developing unit 8 is inserted into the first support frame 61 rotated to the attachment / detachment position, the first opening 47a of the exhaust part 47 and the first opening end 61ba of the first relay part 61b are fitted, The exhaust part 47 and the first relay part 61b communicate with each other. On the other hand, the second opening end portion 61bb of the first relay portion 61b opposite to the developing unit 8 is a main body side duct (duct portion) extended from an exhaust fan (not shown here) provided in the apparatus main body. The second opening 55a at the tip of 55 is engaged with the second opening 55a at the development position.

  As a result, when the first support frame 61 to which the developing unit 8 is mounted rotates from the attachment / detachment position to the development position with the first rotation axis X as a fulcrum, the second opening end 61bb of the first relay portion 61b becomes the main body. The side duct 55 slides in the rotation direction with respect to the opening surface of the second opening 55a, and both engage and communicate with each other as shown in FIG. When the two communicate with each other, the exhaust part 47 of the developing unit 8 and the main body side duct 55 communicate with each other via the first relay part 61b, so that an exhaust path for discharging the air in the developing unit 8 from the main body side duct 55 is provided. Can be formed.

  Here, when the first support frame 61 is rotated to connect the exhaust part 47 and the main body side duct 55, if the rotation of the first support frame 61 to the developing position is not appropriate, it is shown in FIG. Thus, there is a possibility that the arrangement of the second opening end portion 61bb with respect to the second opening portion 55a is shifted. When such a displacement occurs, the airtightness in the exhaust path from the exhaust part 47 to the main body side duct 55 is lowered, and there is a possibility that the cooling efficiency in the developing unit 8 is lowered and the toner is scattered.

  As described above, when the air in the developing device is discharged to the outside of the apparatus main body, maintaining the airtightness of the exhaust path is extremely important from the viewpoint of maintaining the cooling in the developing device and preventing toner leakage. . However, Patent Documents 1 and 2 do not disclose or suggest that the developing device is attached to or detached from the apparatus main body, nor does it disclose or suggest the airtightness of the exhaust path from the developing device to the exhaust fan. .

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of effectively discharging the air in a detachable developing device to the outside of the apparatus main body.

  In order to achieve the above object, the present invention provides an image carrier, a developer container that is detachably attached to the apparatus main body, and a developer carrier that is disposed in the developer container and supplies developer to the image carrier. A developing device for exhausting air in the developing container; and an exhaust means connected to the exhaust unit of the developing device and capable of exhausting the air in the developing device to the outside of the apparatus main body. The image forming apparatus includes: a duct portion extending from the exhaust unit; and a support for the developing device. The image forming device is rotatably supported by the device main body, and the developing device is attached and detached. And a support part that rotates between the attaching / detaching position and the developing position where the attached developing device supplies the developer to the image carrier, and the support part includes the exhaust part and the exhaust part. A cylindrical relay portion that relays between the duct portion, The first opening end of the joint is connected to the duct on the rotation shaft of the support, and the second opening end opposite to the first opening is The developing device is attached to the support portion rotated to the attachment / detachment position, and is connected to the exhaust portion.

  Further, the present invention is characterized in that the second opening end is arranged at a position different from the first opening end in the direction perpendicular to the rotation shaft.

  According to the first configuration of the present invention, the duct portion is extended from the exhaust unit and is for supporting the developing device. A support portion that rotates between a position and a developing position at which the mounted developing device supplies developer to the image carrier, and the support portion relays between the exhaust portion and the duct portion. A support portion in which the first opening end portion of the relay portion is connected to the duct portion on the rotation shaft of the support portion, and the second opening end portion is rotated to the attachment / detachment position. Since the arrangement of the first opening end portion of the relay portion and the duct portion does not deviate even when the support portion rotates by connecting the exhaust device to the exhaust portion by mounting the developing device to the exhaust portion, the exhaust means from the exhaust portion of the developing means In the developing device that can be removed, it is possible to prevent a decrease in hermeticity in the exhaust route up to It is possible to discharge the air efficiently to the apparatus main body outside.

  According to the second configuration of the present invention, in the image forming apparatus having the first configuration, the second opening end is positioned at a position different from the first opening end in the direction perpendicular to the rotation shaft. This arrangement is effective because the degree of freedom in disposing the exhaust section in the developing device can be increased.

1 is a schematic configuration diagram of an image forming apparatus including an image reading apparatus according to an embodiment of the present invention. Side surface sectional view of the developing device used in the image forming apparatus of this embodiment The perspective view of the image development apparatus used for the image forming apparatus of this embodiment. A perspective view showing the periphery of the second support frame Side view showing the periphery of the second support frame The perspective view which shows the state by which the developing device was mounted | worn with the 2nd support frame rotated to the attachment or detachment position. The side view which shows the state with which the developing device was mounted | worn with the 2nd support frame rotated to the attachment or detachment position. The perspective view which shows the state which the 2nd support frame rotated with the image development apparatus to the image development position. The side view which shows the state which the 2nd support frame rotated with the image development apparatus to the image development position. The fragmentary perspective view which shows the state by which the image development apparatus was arrange | positioned in the image development apparatus in the image development position. The fragmentary perspective view which shows the state by which the image development apparatus was arrange | positioned in the attachment / detachment position in the conventional image forming apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus including an image reading apparatus according to an embodiment of the present invention. In FIG. 1, in the image forming apparatus 100 (here, a digital multi-function peripheral is shown as an example), when performing a copying operation, image data of a document is read and converted into an image signal by an image reading apparatus 6 described later. On the other hand, in the image forming unit 3 in the MFP main body 2, the photosensitive drum 5 rotating in the direction A in the figure is uniformly charged by the charging unit 4, and is based on the document image data read by the image reading device 6. An electrostatic latent image is formed on the photosensitive drum 5 by a laser beam from an exposure unit (laser scanning unit or the like) 7, and a developer (hereinafter referred to as toner) is applied to the electrostatic latent image by a developing unit (developing device) 8. A toner image is formed by adhesion. The toner is supplied to the developing unit 8 from the toner container 9.

  The sheet is conveyed from the sheet feeding mechanism 10 to the image forming unit 3 via the sheet conveying path 11 and the registration roller pair 12 toward the photosensitive drum 5 on which the toner image is formed as described above. 3, the toner image on the surface of the photosensitive drum 5 is transferred to the sheet by the transfer roller 13 (image transfer unit). The sheet onto which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to a fixing unit 14 having a fixing roller pair 14a to fix the toner image. The paper that has passed through the fixing unit 14 is sent to a paper conveyance path 15 that branches in a plurality of directions, and is fed by a path switching mechanism 21, 22 having a plurality of path switching guides provided at branch points of the paper conveyance path 15. The transport directions are sorted, and the sheets are discharged as they are (or after being sent to the sheet transport path 16 and double-sided copying) to the sheet discharge section including the first discharge tray 17a and the second discharge tray 17b.

  Although not shown, a static elimination device that removes residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 18. Further, the paper feed mechanism 10 is detachably attached to the multifunction machine main body 2 and includes a plurality of paper feed cassettes 10a and 10b for storing paper, and a stack bypass (manual feed tray) 10c provided above the paper feed cassettes 10a and 10b. These are connected to the image forming unit 3 including the photosensitive drum 5 and the developing unit 8 by the paper transport path 11.

  An image reading device 6 is disposed on the upper part of the apparatus main body. The image reading unit 6 reads image information of a document. When reading each document by hand, the document reading device 27 is opened and the contact glass 6a provided on the upper surface of the apparatus main body is opened. When a document is placed on the document stack and the document bundle is automatically read one by one, the document bundle is placed on the paper feed tray 27a of the document transport device 27 in a closed state. When the original bundle is placed on the paper feed tray 27a, the originals one by one from the original bundle are automatically and sequentially sent onto the contact glass 6a. In any case, the original positioned on the contact glass 6a is irradiated with light from an exposure lamp (not shown), and the reflected light is photoelectrically converted as image light through an optical system such as a reflection mirror (not shown) and an imaging lens. Part (CCD).

  Specifically, the sheet conveyance path 15 first branches into a left and right fork on the downstream side of the fixing roller pair 14a, and one path (a path branching rightward in FIG. 1) communicates with the first discharge tray 17a. It is configured as follows. The other path (the path that branches in the left direction in FIG. 1) is bifurcated via the conveying roller pair 19, and the other path (the path that branches in the left direction in FIG. 1) is the second discharge tray 17b. It is comprised so that it may communicate with. On the other hand, the other path (the path that branches downward in FIG. 1) is configured to communicate with the sheet conveyance path 16.

  Further, an exhaust fan 57 is provided on the back side of the apparatus main body to exhaust air discharged from an exhaust section 47 of the developing unit 8 described later to the outside of the apparatus main body. The main body side fan 55 (see FIG. 10) extends from the exhaust fan 57, and the second opening 55a (see FIG. 10) of the main body side fan 55 is connected to the exhaust portion via the second relay portion 53, as will be described later. 47 is connected. Further, a filter (not shown) is arranged at a connection portion of the exhaust fan 57 with the main body side duct 55 so that toner or the like is captured by the filter.

  FIG. 2 is a side sectional view of a developing device used in the image forming apparatus of the present embodiment, and FIG. 3 is a perspective view. 2 shows a state viewed from the back side of FIG. 1, and the arrangement of each member in the developing device is opposite to that in FIG.

  As shown in FIG. 2, the developing unit 8 includes a developing container 30 in which a two-component developer (hereinafter simply referred to as a developer) is accommodated, and the developing container 30 is stirred and conveyed by partition walls 30a and 30b. 31, a supply transfer chamber 32, and a collection transfer chamber 33. In the agitating / conveying chamber 31 and the supply / conveying chamber 32, the agitating / conveying screw 35 a and the supplying and conveying the toner (positively charged toner) supplied from the toner container 9 (see FIG. 1) are mixed with the carrier and stirred. Each screw 35b is rotatably arranged. In the collection and conveyance chamber 33, a collection and conveyance screw 35c for conveying the developer peeled off from a magnetic roller 40 (described later) is rotatably disposed.

  Then, the developer is agitated by the agitating and conveying screw 35a and the supply and conveying screw 35b while being conveyed in the axial direction (perpendicular to the paper surface of FIG. 2), and passes through the developer (not shown) formed at both ends of the partition wall 30a. It circulates between the agitating and conveying chamber 31 and the supply and conveying chamber 32 through the path. Further, the developer peeled off from the magnetic roller 40 (described later) is transported in the axial direction by the collecting and transporting screw 35c, and the developer in the supply stirring chamber 32 from a communication portion (not shown) formed at one end of the partition wall 30b. To join. That is, a developer circulation path is formed in the developer container 30 by the agitating and conveying chamber 31, the supply and conveying chamber 32, the recovery and conveying chamber 33, the developer passage and the communication portion.

  The developing container 30 extends diagonally upward to the right in FIG. 2. A magnetic roller 40 is disposed above the supply / conveyance screw 35 b in the developing container 30, and a developing roller 41 is diagonally upward to the right of the magnetic roller 40. Opposed. The developing roller 41 faces the photosensitive drum 5 (see FIG. 1) on the opening side (the right side in FIG. 2) of the developing container 30, and the magnetic roller 40 is rotated clockwise in FIG. The developing roller 41 rotates counterclockwise in the drawing.

  A toner concentration sensor (not shown) is disposed in the agitating / conveying chamber 31 so as to face the first agitating / conveying screw 35a. Based on the detection result of the toner concentration sensor, the toner container 9 passes through a toner supply port (not shown). Toner is supplied to the agitating / conveying chamber 31. As the toner concentration sensor, for example, a magnetic permeability sensor that detects the magnetic permeability of a two-component developer composed of toner and magnetic carrier in the developing container 30 is used.

  The magnetic roller 40 is composed of a non-magnetic rotating sleeve that rotates clockwise in FIG. 2 and a fixed magnet body having a plurality of magnetic poles enclosed in the rotating sleeve.

  The developing roller 41 includes a cylindrical developing sleeve that rotates counterclockwise in FIG. 2 and a developing roller side magnetic pole that is fixed in the developing sleeve. The magnetic roller 40 and the developing roller 41 face each other. It faces with a predetermined gap at (opposite position). The developing roller side magnetic pole has a different polarity from the opposing magnetic pole (main pole) of the fixed magnet body.

  Further, a spike cutting blade 45 is attached to the developing container 30 along the longitudinal direction of the magnetic roller 40 (a direction perpendicular to the paper surface of FIG. 2), and the spike cutting blade 45 is rotated in the direction of rotation of the magnetic roller 40 (see FIG. In the middle clockwise direction), it is positioned upstream of the position where the developing roller 41 and the magnetic roller 40 face each other. A slight gap (gap) is formed between the tip of the ear cutting blade 45 and the surface of the magnetic roller 40.

  A DC voltage (hereinafter referred to as Vslv (DC)) and an AC voltage (hereinafter referred to as Vslv (AC)) are applied to the developing roller 41, and a DC voltage (hereinafter referred to as Vmag (DC)) is applied to the magnetic roller 40. And an alternating voltage (hereinafter referred to as Vmag (AC)) is applied. These DC voltage and AC voltage are applied from the developing bias power source to the developing roller 41 and the magnetic roller 40 via a bias control circuit (both not shown).

  As described above, the developer is agitated by the agitating / conveying screw 35a and the supply / conveying screw 35b, and is circulated through the agitating / conveying chamber 31 and the supplying / conveying chamber 32 in the developing container 30 to charge the toner. The developer is conveyed to the magnetic roller 40. Then, a magnetic brush (not shown) is formed on the magnetic roller 40, and the thickness of the magnetic brush on the magnetic roller 40 is regulated by the earbrushing blade 45, and then the opposite portion between the magnetic roller 40 and the developing roller 41. A thin toner layer is formed on the developing roller 41 by the potential difference ΔV between the Vmag (DC) conveyed and applied to the magnetic roller 40 and the Vslv (DC) applied to the developing roller 41 and a magnetic field.

  The thickness of the toner layer on the developing roller 41 varies depending on the resistance of the developer and the rotational speed difference between the magnetic roller 40 and the developing roller 41, but can be controlled by ΔV. When ΔV is increased, the toner layer on the developing roller 41 is thickened, and when ΔV is decreased, the toner layer is thinned. The range of ΔV at the time of development is generally about 100V to 350V.

  The toner thin layer formed on the developing roller 41 by the magnetic brush is conveyed to the opposite portion between the photosensitive drum 5 and the developing roller 41 by the rotation of the developing roller 41. Since Vslv (DC) and Vslv (AC) are applied to the developing roller 41, the toner flies due to a potential difference with the photosensitive drum 5, and the electrostatic latent image on the photosensitive drum 5 is developed. .

  The remaining toner that is not used for development is conveyed again to the opposite portion between the developing roller 41 and the magnetic roller 40 and is collected by the magnetic brush on the magnetic roller 40. Then, the magnetic brush is peeled off from the magnetic roller 40 at the same pole portion of the fixed magnet body, and then falls into the collection conveyance chamber 33. The developer in the collection conveyance chamber 33 is conveyed in the axial direction by the collection conveyance screw 35c, and merges with the developer in the supply conveyance chamber 32 from a communication portion (not shown).

  Thereafter, a predetermined amount of toner is replenished from a toner replenishing port (not shown) based on a detection result of a toner density sensor (not shown), and an appropriate toner concentration is again circulated through the supply transport chamber 32 and the agitation transport chamber 31 The two-component developer is uniformly charged. This developer is again supplied onto the magnetic roller 40 by the supply stirring screw 35 b to form a magnetic brush, and is conveyed to the ear cutting blade 45.

  Further, in the developing container 30, a first through hole 30 c is formed in the vicinity of the developing roller 41 on the right side wall of FIG. 2, and a second through hole 30 d is formed in the vicinity of the magnetic roller 40. A plurality of the first through holes 30c and the second through holes 30d are formed along the longitudinal direction of the developing container 30 (a direction perpendicular to the paper surface of FIG. 2).

  Further, an exhaust part 47 made of a duct is provided on the outer side surface of the right side wall, and as shown in FIG. 3, a first opening is formed at one longitudinal end (right end in the figure) of the exhaust part 47. 47a is formed. The air that has moved from the inside of the developing container 30 to the exhaust part 47 via the first through hole 30c and the second through hole 30d moves to the first opening part 47a, and the second relay part 53 described later from the first opening part 47a. (See FIG. 4).

  In the developing container 30, an air flow generated by the counterclockwise rotation of the developing roller 41 in FIG. 2 between the opposing portion of the developing roller 41 and the magnetic roller 40 and the right side wall of the developing container 30, The air flow generated by the clockwise rotation of the magnetic roller 40 in FIG. 2 is merged, and the pressure is more positive than the other portions. For this reason, the toner tends to scatter from the merging point toward the opening toward the photosensitive drum 5 provided at the upper end of the developing container 30.

  Therefore, by forming the first through hole 30c and the second through hole 30d, the internal pressure around the merging point is reduced to prevent toner scattering. In particular, the toner moving from the merging point to the opening is moved to the exhaust part 47 through the first through hole 30c and collected. Further, the air moved from the developing container 30 to the exhaust unit 47 moves to the main body side duct 55 via the second relay unit 53 as will be described later, and is then moved to the outside of the apparatus main body by the exhaust fan 57 (see FIG. 1). Discharged.

  FIG. 4 is a perspective view showing the periphery of the second support frame, and FIG. 5 is a side view. FIG. 6 is a perspective view showing a state in which the developing device is mounted on the second support frame rotated to the attachment / detachment position, and FIG. 7 is a side view. FIG. 8 is a perspective view showing a state where the second support frame is rotated to the developing position together with the developing device, and FIG. 9 is a side view. Portions common to FIGS. 1 to 3 are denoted by common reference numerals and description thereof is omitted.

  As shown in FIG. 4, a second support frame (support portion) 51 that can support the developing unit 8 is disposed in the apparatus main body. The second support frame 51 is arranged along a direction perpendicular to the conveyance direction of the paper on which an image is formed. The second support frame 51 includes a back side frame portion 51a provided along the back side plate 50a of the apparatus body, a front side frame portion 51b provided along the front side plate 50b, a back side frame 51a, and a front side frame. 51b, and a bottom surface portion 51c on which the developing unit 8 can be placed.

  The 2nd relay part 53 is provided along the upper end part of the inner surface of the back side frame part 51a. The third opening end portion (first opening end portion) 53a on the left side of FIG. 4 in the second relay portion 53 is bent into a substantially L shape so that the back side frame portion 51a faces the back side (the back side in the figure). Further, it penetrates through an engagement hole (not shown) formed in the back side plate 50a in a rotatable manner.

  Further, the third opening end portion 53a is fitted to the second opening portion 55a (see FIG. 10) of the main body side duct 55 while being rotatable and airtight. Thereby, while the 2nd relay part 53 and the main body side duct 55 are connected in the state in which airtightness was maintained, the back side frame part 51a with respect to the back side board 50a in the state connected in this way, The third opening end 53a is pivotally supported with the fulcrum as a fulcrum.

  Further, the fourth opening end portion (second opening end portion) 53b on the right side in FIG. 4 in the second relay portion 53 is bent into a substantially L shape and protrudes toward the front side (the front side in the drawing). The first opening 47a of the exhaust part 47 of the developing unit 8 can be fitted to the fourth opening end 53b in a state where the airtightness is maintained.

  The second support frame 51 is connected to a drive motor (not shown), and is a drive for transmitting rotational driving to the agitating and conveying screw 35a, the supply and conveying screw 35b, the collecting and conveying screw 35c, the magnetic roller 40, and the developing roller 41. A coupling 54 is arranged.

  On the other hand, an engagement hole 51ba is formed at the upper end portion of the front side frame portion 51b so as to be rotatably engaged with a protruding portion 50ba that protrudes outward in the longitudinal direction from the front side plate 50b. Thereby, the front side frame part 51b is rotatably supported by the front side plate 50b. Accordingly, the second support frame 51 is supported by the rear side plate 50a and the front side plate 50b so as to be rotatable in the paper transport direction. Further, the second rotation shaft (rotation shaft) Y, which is the rotation fulcrum of the second support frame 51, is provided with a third opening end portion 53a on the back surface side and an engagement hole 51ba on the front surface side.

  The bottom surface 51c of the second support frame 51 is placed on a cam member (not shown) that is rotated by the lever 56. When the lever 56 is rotated clockwise as shown in FIG. 51 is rotated clockwise with the second rotation axis Y as a fulcrum, and the developing unit 8 is disposed at a detachable position.

  Further, when the lever 56 is rotated counterclockwise in the figure, the second support frame 51 is rotated counterclockwise with the second rotation axis Y as a fulcrum, and the developing roller 41 is moved with respect to the photosensitive drum 5. They are opposed to each other with a predetermined gap, and are arranged at a development position where toner can be supplied to the photosensitive drum 5 (see FIG. 7).

  The developing unit 8 is attached to and detached from (attached to and detached from) the second support frame 51 by being inserted into and removed from the second support frame 51 disposed in the attachment / detachment position along the longitudinal direction, and the exhaust unit. The first opening 47 a of 47 is fitted and detached from the fourth opening end 53 b of the second relay portion 53. In addition, when the second support frame 51 is rotated to the developing position with the developing unit 8 attached, toner can be supplied from the developing unit 8 to the photosensitive drum 5.

  Next, the attaching / detaching operation of the developing unit 8 will be described. First, when the developing unit 8 is inserted from the front side of the apparatus main body along the longitudinal direction of the second support frame 51 in a state where the second support frame 51 is disposed at the attachment / detachment position, as shown in FIGS. The developing unit 8 is supported by the second support frame 51. At this time, the first opening 47 a of the exhaust portion 47 of the developing unit 8 is fitted with the fourth opening end portion 53 b of the second relay portion 53, and the exhaust portion 47 and the second relay portion 53 communicate with each other. Thereby, the exhaust part 47 and the main body side duct 55 communicate with each other through the second relay part 53 in a state where airtightness is maintained.

  When the lever 56 is rotated counterclockwise from this state, as shown in FIGS. 8 and 9, the second support frame 51 is attached and detached with the second rotation axis Y (third opening end 53a) as a fulcrum. The toner can be supplied from the developing unit 8 to the photosensitive drum 5 by rotating from the position to the developing position. At this time, since the second support frame 51 rotates with the third opening end 53a as a fulcrum, airtightness between the third opening end 53a and the second opening 55a is maintained during the rotation. . Further, the airtightness between the fourth opening end portion 53b and the first opening portion 47a is maintained.

  As described above, in the present embodiment, the main body side duct 55 extended from the exhaust fan 57 and the developing unit 8 are supported. The developing unit 8 is rotatably supported by the apparatus main body. A second support frame 51 that rotates between the attach / detach position and the development position at which the mounted developing unit 8 supplies toner to the photosensitive drum 5 is provided. It has a cylindrical second relay part 53 that relays the exhaust part 47 of the unit 8 and the main body side duct 55, and the third opening end part 53 a of the second relay part 53 is connected to the second support frame 51. The fourth opening end 53b is connected to the exhaust unit 47 by mounting the developing unit 8 on the second support frame 51 rotated to the attachment / detachment position.

  Thus, even if the second support frame 51 rotates, the arrangement of the third opening end portion 53a of the second relay portion 53 and the main body side duct 55 does not deviate from the exhaust portion 47 of the developing unit 8 to the exhaust fan 57. It is possible to prevent a decrease in hermeticity in the exhaust path up to. Therefore, the air in the detachable developing unit 8 can be effectively discharged outside the apparatus main body.

  Further, in the present embodiment, the fourth opening end portion 53b is arranged at a position different from the third opening end portion 53a in the direction perpendicular to the second rotation axis Y. Since the degree of freedom can be increased, it is effective. However, as long as the third opening end portion 53a is disposed on the second rotation axis Y, the arrangement of the fourth opening end portion 53b is not particularly limited. It may be formed from a straight cylindrical member, and the third opening end 53a and the fourth opening end 53b may be arranged along the second rotation axis Y.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, the shape of the second relay unit 53 shown in the above embodiment, the arrangement in the developing unit 8 and the like are not particularly limited to the above embodiment, and can be appropriately set according to the apparatus configuration and the like. .

  In the above embodiment, the monochrome image forming apparatus 100 having the image reading unit 6 is used. However, the present invention can be applied to an image forming apparatus other than a multifunction peripheral, for example, a laser printer or a facsimile machine. Needless to say, the present invention can be applied to a color complex machine, a color printer, a color fax machine, and the like.

  The present invention is for supporting a duct portion extending from an exhaust unit and a developing device, and is rotatably supported by the apparatus main body, and an attaching / detaching position where the developing device is attached / detached, and an attached developing device. A support portion that rotates between the developing position at which the apparatus supplies developer to the image carrier, and the support portion includes a cylindrical relay portion that relays between the exhaust portion and the duct portion. The first opening end portion of the relay portion is connected to the duct portion on the rotation shaft of the support portion, and the second opening end portion is mounted by mounting the developing device on the support portion rotated to the attachment / detachment position. An image forming apparatus connected to an exhaust unit.

  Thereby, air in the detachable developing device can be effectively discharged to the outside of the main body of the apparatus, and toner scattering can be prevented.

5 Photosensitive drum 8 Developing unit (developing device)
30 Developing container 30c First through hole 30d Second through hole 47 Exhaust part 47a First opening 50a Rear side plate 50b Front side plate 50ba Protruding part 51 Second support frame (support part)
51a Rear side frame part 51b Front side frame part 51ba Engagement hole 51c Bottom face part 53 Second relay part (relay part)
53a Third opening end (first opening end)
53b Fourth opening end (second opening end)
55 Body side duct (duct part)
55a Second opening 100 Image forming apparatus Y Second rotation axis (rotation axis)

Claims (2)

An image carrier;
A detachably mounted developer body; a developer carrier disposed in the developer container for supplying a developer to the image carrier; and an exhaust unit for discharging the air in the developer container; A developing device having
An image forming apparatus comprising: an exhaust unit coupled to an exhaust portion of the developing device and capable of exhausting air in the developing device to the outside of the apparatus main body;
A duct portion extending from the discharge means;
The developing device is for supporting the developing device, is rotatably supported by the device main body, and is attached to and detached from the developing device. The attached developing device supplies developer to the image carrier. A developing position that rotates, and a support portion that rotates between,
The support part has a cylindrical relay part that relays the exhaust part and the duct part,
The first opening end of the relay portion is connected to the duct portion on the rotation shaft of the support portion, and the second opening end opposite to the first opening end is An image forming apparatus connected to the exhaust unit by mounting the developing device to the support unit rotated to the attachment / detachment position.   The image forming apparatus according to claim 1, wherein the second opening end portion is disposed at a position different from the first opening end portion in a direction perpendicular to the rotation shaft.

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