JP4972215B2 - Developing unit and image forming apparatus - Google Patents

Description

  The present invention relates to a developing unit and an image forming apparatus.

  Among the development units equipped in the image forming apparatus so far, as disclosed in Japanese Patent Application Laid-Open No. 2004-228688, there is a development unit in which a developer storage unit that supplies a developer is detachable from the development unit.

JP 2005-17478 A

  On the other hand, this developer unit is pre-filled with a small amount of developer in order to confirm the initial quality and reduce the initial driving load before mounting the developer accommodating unit. Packed and shipped.

  Therefore, when storing and transporting the development unit without the developer supply unit attached, a means for closing the developer supply port of the development unit, that is, the opening through which the developer is supplied from the developer supply unit is necessary. there were.

  As means for closing the opening of the developing unit, means has been used to tape the cylindrical foaming urethane to the opening and close the opening, but as the hole shape of the opening of the developing unit increases, There has been a problem that the pressure contact force of the portion not taped becomes weak and the developer leaks from there. In addition, fixing the tape at a plurality of locations also leads to an increase in cost, and there is also a problem that it takes time and effort when the operator peels off the tape.

  The present invention has been made in view of such circumstances, and the opening of the developing unit is sealed with a sealing member to prevent the developer from leaking from the developing unit and to remove the sealing member. It is an object of the present invention to provide a developing unit and an image forming apparatus having a sealing member that can be easily performed.

In order to solve the above-described problems, the developing unit according to the present invention forms a developer image using a developer discharged through a developer discharge port provided in the first bottom surface portion of the developer containing unit . In the developing unit, a housing in which the developer containing unit is detachably mounted, and a position facing the developer discharging port when the developer containing unit is mounted on the housing are provided corresponding to the shape of the developer discharging port. The developer supply port for supplying the developer discharged through the developer discharge port into the housing and the periphery of the developer supply port are provided when the developer containing unit is attached to the housing. A sealing member made of an elastic material that can be compressed by a pressing force and a sealing member that seals the developer supply port, and the sealing member is formed in a circular arc shape corresponding to the shape of the developer accommodating unit Second bottom surface portion A, and the cap member for covering a surface developer supply opening is provided in the casing, is constituted by a locking member for locking the cap member to the housing, the second bottom surface portion is provided with a developer supply port The cap member is locked to the casing so as to press-contact the seal member against the formed surface side to seal the developer supply port. The sealing surface of the developer supply port by the second bottom surface portion is the developer. It is characterized by not being located on the inner side of the housing than the surface provided with the supply port.

  According to this configuration, in the developing unit in which the developer containing unit can be mounted, the developer leaks from the developing unit by covering the developer supply port provided in the developing unit with the sealing member and the cap member. Can be prevented.

It is sectional drawing which shows the structure of the image development part which is the principal part of a image development unit. 2 is a cross-sectional view illustrating the image forming apparatus main body 100. FIG. It is a perspective view of the appearance of the developing unit. FIG. 3 is a cross-sectional view of the developing unit as viewed from the Y-axis direction. FIG. 3 is a perspective view of the appearance of a developer storage unit. FIG. 3 is a perspective view of the appearance of a developer storage unit. FIG. 10 is a perspective view illustrating a mounting method for mounting the developer containing unit to the developing unit. FIG. 10 is a perspective view illustrating a mounting method for mounting the developer containing unit to the developing unit. It is a perspective view which shows a mode that the cap member was mounted | worn to the image development unit. It is sectional drawing seen from the Y-axis direction which shows a mode that the cap member was mounted | worn to the image development unit. It is sectional drawing seen from the X-axis direction which shows a mode that the cap member was mounted | worn to the image development unit. It is a perspective view which shows a mode that the sealing tape member was mounted | worn with the developer supply port of the image development unit. It is sectional drawing seen from the Y-axis direction which shows a mode that the sealing tape member was mounted | worn with the developer supply port of the image development unit. FIG. 4 is a top view of a developer supply port as viewed from the Z-axis direction. It is a perspective view of the appearance of the developing unit. It is a principal part enlarged view in 2nd Embodiment. It is a perspective view which shows a mode that the cap member was mounted | worn to the image development unit. It is a principal part enlarged view in 3rd Embodiment. FIG. 4 is a top view of a developer supply port as viewed from the Z-axis direction. FIG. 4 is a top view of a developer supply port as viewed from the Z-axis direction. It is sectional drawing seen from the X-axis direction which shows a mode that the cap member was mounted | worn to the image development unit.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a developing unit 45 which is a main part of the developing unit 40 according to the present invention.

  The developing unit 45 includes a photosensitive drum 1, a charging roller 2, an exposure device 3, a developer 4, a developing roller 6, a developing blade 7, a developer supply roller 8, and a cleaning blade 9.

  A drum-shaped photosensitive drum that is rotatable about a central axis is mounted in a developing unit 40 that detachably mounts a developer containing unit 5 that contains an opening and closing mechanism for containing the developer 4 and supplies it. 1 is held.

  The photosensitive drum 1 can store electric charges on the outer peripheral surface thereof, the electric charges on the outer peripheral surface are removed by exposure, and a printed image is formed by an electrostatic latent image.

  Around the photosensitive drum 1, a charging roller 2 for charging the outer peripheral surface of the photosensitive drum 1 to a uniform potential is provided so as to contact the photosensitive drum 1 with a constant pressure. An exposure device 3 that exposes the outer peripheral surface of the photosensitive drum 1 to form an electrostatic latent image based on the print data is attached to the upper portion of the photosensitive drum 1.

  The developing roller 6 that develops the developer by attaching the developer to the electrostatic latent image described above, the transfer roller 12 attached to the image forming apparatus main body 100, and the transfer roller 12 is charged to a charge opposite to that of the developer 4. A cleaning blade 9 for scraping off the waste developer remaining on the outer peripheral surface of the photosensitive drum 1 after being transferred to the recording medium 13 is disposed.

  The developing roller 6 and the developer supply roller 8 that is in pressure contact with the developing roller are in the developing unit 45. The developer 4 discharged from the developer discharge port 34 of the developer supply unit 5 is supplied to the pressure contact portion between the developing roller 6 and the developer supply roller 8. Further, the developing blade 7 is disposed so as to be in pressure contact with the outer peripheral surface of the developing roller 6, and the developer 4 attached to the outer peripheral surface of the developing roller 6 is uniformly thinned.

  The developing unit 40 includes an image forming apparatus main body so that the photosensitive drum 1 mounted in the unit can cooperate with the transfer roller 12 installed in the image forming apparatus main body 100 via the transfer belt 11. 100 is detachably mounted.

  Note that the X, Y, and Z coordinate axes in FIG. 1 take the Y axis parallel to the rotation axis of the photosensitive drum 1, and set the X axis parallel to the direction in which the recording body 13 is conveyed. The Z axis is set in a direction perpendicular to the axis. The coordinates used in the drawings described later also indicate the same coordinate axis.

  Therefore, the photosensitive drum 1 is rotationally driven in the A direction from the arrow B around the Y axis, and the recording medium 13 is conveyed in the positive direction of the X axis.

  FIG. 2 is a cross-sectional view illustrating the image forming apparatus main body 100.

  The image forming apparatus main body 100 includes a recording medium cassette 20, a recording medium feeding unit 22, conveyance rollers 16 to 19, a transfer belt 11, a transfer roller 12, and a fixing unit 25.

  A recording medium cassette 20 for storing the recording medium 13 is disposed at the bottom of the image forming apparatus main body 100. A recording medium feeding unit 22 that feeds the recording medium 13 from the recording medium cassette 20 is provided at the upper end of the sheet feeding cassette 20 in the negative direction of the X axis. The fed recording medium 13 is conveyed in the direction of arrow A to B around the Y axis along the sheet conveying path 15 having the conveying rollers 16 to 19 and is attached to the transfer belt 11 by the electrostatic effect, and then in the X axis direction. Will go on.

  When the recording medium 13 on the transfer belt 11 passes through the pressure contact portion between the photosensitive drum 1 and the transfer roller 12, the print image is transferred from the photosensitive drum 1 to the recording medium 13. The print image transferred from the photosensitive drum 1 to the recording medium 13 is fixed on the recording medium 13 by the fixing unit 25 and then discharged to the outside of the image forming apparatus main body 100.

  3A is a perspective view of the appearance of the developing unit 40, and FIG. 3-B is a cross-sectional view of the developing unit 40 as viewed from the Y-axis direction.

  The development unit 40 includes a development unit 45, a side frame 50, a projection 51, guide projections 64 and 65, a frame upper 52, a developer supply port 52-b, and a urethane foam sheet 53.

  The side frame 50 of the developing unit 40 is provided with a protrusion 51 for fitting into an opening 35 of the developer accommodating unit 5 described later. Further, a guide protrusion 64 is provided on the side frame 50, and a guide protrusion 64 is provided on an outer peripheral frame wall portion that is a surface facing the side frame 50 on the Y axis minus direction side of the frame upper 52 that is a mounting portion of the developer containing unit 5. 65 is provided.

  A developer receiving port that communicates with the inside of the developing unit 40 is located at a position facing the developer discharge port 34 of the developer accommodating unit 5 to be mounted in the recessed portion 52-a that is the bottom surface of the developer accommodating unit 5 mounting portion. A certain supply port 52-b is formed.

  Further, as shown in FIG. 3B, a urethane foam sheet 53 having a thickness of 2 mm is bonded around the supply port 52-b.

  4A and 4B are perspective views of the appearance of the developer containing unit 5, and FIG. 5A is a perspective view for explaining a mounting method for mounting the developer containing unit 5 to the developing unit 40. FIG. 5B is a cross-sectional view seen from the Y-axis direction showing a state in which the developer containing unit 5 is completely attached to the developing unit 40.

  The developer storage unit 5 includes a developer storage unit 30, a developer filling port 31, a cap member 32, a lever member 33, a developer discharge port 34, and an opening 35 provided at the end of the unit. A screw member 36 and a developer stirring bar 39 are provided.

  As shown in FIGS. 4A and 4B, the bottom surface portion of the developer containing unit 5 is formed in an arc shape in cross section, and a developer discharge port 34 for discharging the developer 4 is formed at the lowermost center. ing. Further, the developer containing unit 5 is provided with a developer filling port 31 at an end portion in the longitudinal direction, and the developer filling port 31 is covered and sealed with a removable cap member 32. Further, the cap member 32 is formed with an X-shaped groove 32-a extending in a fan shape from the center of the end surface of the cap member 32.

  When the developer containing unit 5 is attached to the developing unit 40, first, the protrusion 51 provided on the side guide frame 50 is inserted into the opening 35 of the developer supplying unit 5. Next, the developer supply unit 5 is guided so that the guide protrusion 65 is accommodated in the X-shaped groove 32-a. The cap member 32 connected to the lever 33 is rotated by rotating the lever 33, and the guide protrusion 65 and the X-shaped groove 32-a are completely fitted. Therefore, the developer supply unit 5 is fixed with respect to the developing unit 40.

  As illustrated in FIG. 5B, the urethane foam sheet 53 prevents the developer 4 from leaking to the outside when the developer supply unit 5 is mounted on the development unit 40 and the developer 4 is supplied. The developer is compressed between the developer containing unit 5 and the frame upper 52 to prevent the developer 4 from leaking to the outside.

  FIG. 6 is a perspective view showing a state where the cap member 63 which is a sealing member according to the present invention is attached to the developing unit 40. FIG. 7 is a cross-sectional view of the cap unit 63, which is a sealing member according to the present invention, attached to the developing unit 40 as viewed from the Y-axis direction, and FIG. 8 is a cross-sectional view as viewed from the X-axis direction.

  The cap member 63 includes a polystyrene cap portion main body formed in a circular arc shape corresponding to the shape of the developer accommodating unit mounting surface (frame upper 52) of the developing unit 40, and a Y axis plus from the center portion of the cap member 63. And a lever member 63-a provided on the upper end of the cap member 63 on the Y axis plus direction side. In addition, in order to increase the rigidity of the cap member 63, the ribs in the longitudinal direction and the ribs in the short direction are formed on the inner side of the arc wall formed in the arc shape, thereby forming a grid-like rib.

  The cap member 63 is attached to a recessed portion 52-a of the developing unit 40 in which a small amount of the developer 4 is placed.

  The cap member 63 is installed in the developing unit 40 by first bringing the cap member 63 in the Y-axis minus direction while bringing the bottom surface of the cap member 63 in the Y-axis minus direction side into contact with the recess 52-a of the developing unit 40. Slide until the end of the cap member 63 is engaged with the guide protrusion 65 provided on the frame upper 52.

  When the end of the cap member 63 is engaged by sliding, the entire cap member 63 fits into the frame upper 52, and the cap member 63 is placed so that the bottom surface of the cap member 63 completely covers the recessed portion 52-b of the developing unit 40. . Next, as shown in FIGS. 6 and 8, the cap member 63 is tilted around the Y axis in the direction of arrow A → B, and the lever member 63-a is provided in the guide projection 64 provided on the side frame 50 of the developing unit 40. , The cap member 63 is fixed to the developing unit 40.

  At this time, the cap member 63 is engaged with the developing unit 40 by the engaging portions formed at both ends in the longitudinal direction of the cap member 63, and the urethane foam sheet 53 is, as shown in FIG. Compressed between the bottom surface portion 63 and the frame upper 52, prevents a small amount of the image agent 4 existing in the developing unit 40 from leaking to the outside. Further, since the cap member 63 is formed with the ribs as described above, the deformation can be suppressed and the urethane foam sheet 53 can be compressed firmly.

  It should be noted that when removing the cap member 63 from the developer unit 40, the procedure is reversed from the installation method described above. That is, when the lever member 63-a of the cap member 63 is held and rotated around the Y axis in the direction of arrow B → A, the engagement with the guide protrusion 65 is released, so that the cap member 63 is removed from the developer unit 40. Can be removed.

  After removing the cap member 63 from the developing unit 40, the developer containing unit 5 is mounted on the developing unit 40 and mounted at a predetermined position of the image forming apparatus 100, whereby the image forming apparatus 100 can perform a printing operation. . The removed cap member 63 can prevent developer leakage from the developer supply port 52-b when an old developing unit is installed and discarded / or recycled.

  As described above, according to the first embodiment, the urethane foam sheet 53 that is an elastic member is disposed around the developer supply port 52-b of the developing unit 40, and the developer supply port 52 is compressed while compressing it. By providing the cap member 63 covering -b, a stable developer sealing effect can be expected over the entire opening regardless of the size of the supply port. Further, since the operator has to remove the cap member 63 with only one lever operation, the operation can be easily performed. Furthermore, when the cap member 63 is mounted on the developing unit 40 that is no longer needed, it can be performed in the reverse order of the above-described operation without much time and effort.

(Second Embodiment)
FIG. 9 is a perspective view showing a state in which a seal tape member, which is a sealing member according to the present invention, is attached to the developer supply port of the developing unit 40, and FIG. 10 is a view seen from the Y-axis direction.

  In the second embodiment, the seal tape member 70 is used as the sealing means. Since other configurations have many parts in common with the first embodiment, the same reference numerals are used for the reference numerals in the drawings.

  The seal tape member 70 is a predetermined region provided between the developer supply port 52-b provided in the developing unit 40 described above and the urethane foam sheet 71 disposed around the developer supply port 52-b. C is disposed. The predetermined area C will be described with reference to FIG.

  As shown in FIG. 11, the hole formed by the urethane foam sheet 71 has a wide shape with respect to the developer supply port 52-b. At this time, the length in the longitudinal direction of the hole formed by the urethane foam sheet 71 is L2, and the length in the short direction is W2. On the other hand, when the length in the longitudinal direction of the hole formed by the developer supply port 52-b is L1, and the length in the short direction is W1, the following relational expression holds.

  W2> W1, W2-W1 ≧ 4 mm, L2> L1, L2-L1 ≧ 4 mm

  FIG. 12 shows the developing unit 40 having a predetermined region C formed by satisfying the above relational expression. A urethane foam sheet 71 having a thickness of 2 mm is disposed with a predetermined area C around the developer supply port 52-b, so that an adhesive margin portion having a width of at least 2 mm is provided around the developer supply port 52-b. The sealing tape member 70 is disposed in this portion.

  Also, as shown in FIG. 10, the seal tape member 70 is disposed only in the predetermined region C described above, and the seal tape member 70 is not in contact with the urethane foam sheet 71. Therefore, the adhesive component of the seal tape 70 does not adhere to the urethane foam sheet 53.

  Further, as shown in FIG. 9, the end of the seal tape member 70 in the negative Y-axis direction is bonded to the upper edge of the outer peripheral frame wall that is the surface facing the side frame 50, and Folded in the direction of the outer surface and bonded.

  That is, as shown in FIG. 13, the seal tape member 70 covers the drive gear 72 that passes through the portion D of the urethane foam sheet 71 and transmits power to the developer stirring bar 39 provided in the developer containing unit 5. And pasted over the outer wall of the frame upper 52.

  The final end 70-a of the seal tape member 70 is folded back in the direction opposite to the extending direction, and is not bonded to the outer wall of the frame upper 52.

  The width of the seal tape member 70 does not exceed W2 described above, and the adhesive for attaching the seal tape member 70 to a predetermined area corresponds to the developer supply port 52-b of the development unit 40. Since the portion to be applied does not contribute to the adhesive force, the adhesive for this portion may be omitted. Further, the same seal tape member 70 with release paper is attached to the new development unit 40.

  When a new or stored developing unit 40 is mounted, the operator has the folded end portion 70-a of the seal tape member 70 and peels it off along the longitudinal direction of the developer supply port 52-b. Thereafter, the developer accommodating unit 5 is mounted on the developing unit 40 and is mounted at a predetermined position of the image forming apparatus 100, whereby the image forming apparatus 100 can perform a printing operation.

  Discard the removed seal tape member 70, or if there is an old development unit, remove the release paper of the seal tape member 70 with release paper and paste it in place to discard or recycle the development unit 40 In doing so, it is possible to prevent the developer 4 from leaking from the developer supply port 52-b.

  Further, even if the developer accommodating unit 5 is to be mounted without removing the seal tape member 70, the seal tape member 70 is disposed so as to cover the drive gear 72. Since the gear for driving the developer stirring bar 39 cannot be engaged with each other, the developer containing unit 5 and the developing unit 40 cannot be connected to each other, so that troubles caused by forgetting to remove the seal tape member 70 can be prevented. Can do.

  Unlike the conventional sealing member that seals the developer supply port, the sealing tape member of this embodiment does not affect the urethane foam sheet at all. In other words, when the developing unit is stored, the urethane foam sheet is not compressed by the sealing member, so there is little distortion of the urethane foam sheet, and the developer sealing performance remains high even when the developer supply unit is attached to the developing unit. Is done.

(Third embodiment)
FIG. 14 is a perspective view showing a state in which a cap member, which is a sealing member according to the present invention, is attached to the developer supply port of the developing unit 40, and FIG. 15 is a cross-sectional view of the principal part viewed from the X-axis direction. is there.

  In the third embodiment, the cap member 80 is used as the sealing means. Since other configurations have many parts in common with the first embodiment, the same reference numerals are used for the reference numerals in the drawings.

  The cap member 80 includes a cap portion main body, a handle member attached to the end portion in the longitudinal direction of the cap member 80, and a rim portion 80-a attached to the cap portion main body.

  The cap member 80 is a predetermined region E provided between the developer supply port 82-b provided in the developing unit 40 described above and the urethane foam sheet 71 disposed around the developer supply port 82-b. The rim portion 80-a is disposed so as to adhere to the surface. The predetermined area E will be described with reference to FIG.

  As shown in FIG. 16, the hole formed by the urethane foam sheet 71 has a wide shape with respect to the developer supply port 82-b. At this time, the length in the longitudinal direction of the hole formed by the urethane foam sheet 71 is L2, and the length in the short direction is W2. On the other hand, when the length in the longitudinal direction of the hole formed by the developer supply port 82-b is L1, and the length in the short direction is W1, the following relational expression holds.

  W2> W1, W2-W1 ≧ 2 mm, L2> L1, L2-L1 ≧ 2 mm

  A rim portion 80-a having a width of approximately 1 mm corresponding to a predetermined region E formed by satisfying the above relational expression is provided on the cap member 80. On the other hand, the corner portions of the four corners of the developer supply port 82-b are formed in a circular arc shape 82-c having an appropriate curvature.

  Further, as shown in FIG. 15, a rim portion 80-a having a size larger than that of the developer supply port 82-b is provided on the outer periphery of the cap member 80. The shape of the part is a tapered shape. Therefore, when the cap member 80 is pushed into the developer supply port 82-b, the tip of the cap member 80 inside the developer supply port 82-b is biased toward the outside of the developer supply port 82-b. Thus, the cap member 80 is fixed in the developer supply port 82-b.

  On the other hand, the 80-b surface of the cap member 80, that is, the rim portion 80-a comes into close contact with the predetermined region E, thereby preventing the developer 4 from leaking.

(Modification of the third embodiment)
A modification of the third embodiment will be described with reference to FIGS. 17 and 18.

  FIG. 17 is a top view of the developer supply port 92-b as viewed from the Z-axis direction. On the other hand, FIG. 18 is a cross-sectional view as seen from the X-axis direction when the cap member 90 in the modified example is attached to the developer supply port 92-b.

  Also in this modification, the cap member 90 is used as the sealing means. Since other configurations have many parts in common with the first embodiment, the same reference numerals are used for the reference numerals in the drawings.

  The cap member 90 has a concave shape for fitting with a cap portion main body, a handle member attached to the longitudinal end portion of the cap member 90, a rim portion 90-a attached to the cap portion main body, and a convex rib portion. Receiving part 90-b.

  As shown in FIG. 17, in a predetermined area E around one developer supply port 92-b, a convex shape for fitting with a concave receiving portion 90-b provided in the cap member 90. The rib portion 92-d is disposed along the periphery of the developer supply port 92-b.

  Other configurations and operations are the same as those of the third embodiment, but the cap member 90 is provided around the developer supply port 92-b so that the cap member 90 is connected to the developer supply port 92-b. It becomes possible to fix to more stably. That is, as shown in FIG. 18, in addition to the force that the tip of the cap member 90 inside the developer supply port 92-b urges toward the outside of the developer supply port 92-b, Both ends are fixed by locking members. Therefore, the cap member 90 is fixed more closely to the developer supply port 92-b.

  As described above, according to the third embodiment and the modification thereof, when the developer storage unit is attached to a new development unit, the operator has the handle portion of the cap member and the length of the developer supply port. The cap member can be easily detached from the developing unit by pulling along the direction. In the case of mounting, the cap member can be easily mounted on the developer supply port of the developing unit and the developer can be sealed in the reverse procedure.

In many cases, a small amount of developer is put in the developing unit in advance in order to carry out inspections necessary at the time of manufacture, and the developing unit is shipped in that state.
By mounting the sealing member in the developing unit in the present invention, it becomes possible to prevent leakage of the developer from the developer unit. Further, since the sealing member in the present invention can be easily detached from the developing unit, the burden on the operator can be reduced.

  Moreover, it is possible to produce the sealing member according to the present invention at a relatively low material cost. Furthermore, since the sealing member of the present invention removed from the new developing unit can be reused for an old developing unit, the running cost can be reduced.

  Each embodiment described above is a preferred embodiment of the present invention, but the present invention is not limited to this, and each configuration can be appropriately changed without departing from the spirit of the present invention. is there.

  The present invention can be applied not only to image forming apparatuses such as printer apparatuses, but also to copiers or facsimile apparatuses, and multifunction machines having various functions such as a copy function, a printer function, a scanner function, and a facsimile function. It is.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Exposure apparatus 4 Developer 5 Developer accommodation unit 6 Development roller 7 Development blade 8 Developer supply roller 9 Cleaning blade 11 Transfer belt 12 Transfer roller 13 Recording medium 14 Print image 16-19 Transport roller 20 Recording medium cassette 21 Stacker 22 Recording medium feeding unit 23 Image forming unit 25 Fixing unit 30 Developer container 31 Developer filling port 32 Cap member 32-a X-shaped groove 33 Lever member 34 Developer discharge port 35 Opening portion 36 Screw member 39 Developer stirring bar 40 Developing unit 45 Developing unit 50 Side frame 51 Protruding part 52 Frame upper 52-a Depressed portions 52-b, 82-b, 92-b on the bottom surface of the developer accommodating unit mounting part Developer supply port 64 , 65 Guide projection 53, 71 Urethane foam sheet 63, 80, 90 Cap member 63-a Lever member 70 Seal tape member 70-a Folding end portion 72 Drive gear 80-a, 90-a Rim portion 80-c Handle portion 90-b Concave receiving portion 92-d Convex shape Rib unit 100 Image forming apparatus main body

Claims (6)

In the developing unit for forming a developer image using the developer discharged through the developer discharge port provided in the first bottom surface portion of the developer containing unit,
A housing in which the developer containing unit is detachably mounted;
The developer provided corresponding to the shape of the developer discharge port at a position facing the developer discharge port when the developer containing unit is attached to the housing, and discharged through the developer discharge port A developer supply port for supplying the developer into the housing;
A seal member that is disposed around the developer supply port and is made of an elastic material that can be compressed by a pressing force applied when the developer containing unit is attached to the housing;
A sealing member for sealing the developer supply port,
The sealing member is
A cap member having a second bottom surface portion having an arcuate cross section corresponding to the shape of the developer containing unit and covering a surface of the housing provided with the developer supply port; and the cap member And the cap member so that the second bottom surface is in pressure contact with the surface on which the developer supply port is provided. The developer supply port is sealed by being locked to
The developing unit, wherein a sealing surface of the developer supply port by the second bottom surface portion is not located closer to an inner side of the housing than a surface provided with the developer supply port.   The developing unit according to claim 1, wherein the cap member has a handle portion for opening the developer supply port sealed by the sealing member.   The said cap member has a rib extended in each direction of a longitudinal direction and a transversal direction, The said rib is formed so that it may become a grid | lattice form, or Claim 2 characterized by the above-mentioned. The developing unit described. The locking member is provided at an end portion in the longitudinal direction of the cap member, and is locked with a locked member provided in the casing in accordance with a rotation operation in which the longitudinal direction of the cap member is a rotation axis direction. The developing unit according to any one of claims 1 to 3, wherein the developing unit is characterized in that: The locking member has a lever portion extending from an end portion in the longitudinal direction of the cap member, and an edge of the lever portion is formed as a locking portion bent in a U-shape, and the locking portion 5. The developing unit according to claim 4, wherein the developing unit is locked with a locked portion provided in the housing in accordance with a rotation operation with the longitudinal direction of the cap member as a rotation axis. A paper feeding unit that feeds recording paper, a transport unit that transports the recording paper in the direction of the developing unit, an exposure unit that forms a latent image, a developing unit that develops a toner image on the latent image, and a recording In an image forming apparatus comprising a transfer unit for transferring a toner image to paper and a fixing unit for fixing the toner image to recording paper,
An image forming apparatus comprising the developing unit according to claim 1.