JP5075030B2 - Toner replenishment mechanism and color image forming apparatus having the same - Google Patents

Description

  The present invention relates to a toner supply mechanism that rotates a container shutter of a toner container in conjunction with an opening / closing operation of a main body cover to open / close a toner supply port of the toner container, and a color image forming apparatus including the toner supply mechanism. is there.

  In an image forming apparatus such as a copying machine or a printer that forms an image on a sheet by electrophotography, an electrostatic latent image formed on an image carrier such as a photosensitive drum is developed as a toner image using toner in a developing device. However, there is known an image forming apparatus that employs a system that replenishes toner from a toner container when the toner in the developing device is consumed and its remaining amount is low.

  In an image forming apparatus provided with such a toner container, the main body cover is opened and the toner container is attached and detached. In order to prevent scattering of the toner when the toner container is attached and detached, the toner container has a container that opens and closes a toner supply port. A shutter is provided, and the toner supply port is closed by the container shutter when the toner is attached and detached, and when the toner container is mounted, the toner supply port is opened by the container shutter to enable toner supply (for example, Patent Documents). 1 and 2).

Incidentally, a toner replenishing mechanism is proposed in which the toner replenishing port is opened and closed by the container shutter in conjunction with the opening and closing operation of the main body cover. A main body joint gear for holding the joint, and a biasing means such as a spring for biasing the joint toward the container shutter side. It functions to open and close the toner supply port of the toner container by rotating the gear, transmitting the rotation to the container shutter through the joint, and rotating the container shutter.
JP 2003-316138 A JP-A-9-120204

  However, in the toner replenishing mechanism, since the main body cover can be closed even if the connection between the container shutter of the toner container and the main body side joint is incomplete, the user can connect the container shutter and the main body side joint. Is incomplete, and the image forming operation starts with the toner supply port of the container shutter closed. In such a case, since rotation is not transmitted to the container shutter, the toner replenishing port does not open and a problem such as toner leakage does not occur, but there is a problem that toner is not replenished from the toner container to the developing device. appear.

  The present invention has been made in view of the above problems, and an object of the present invention is to notify the user when the toner container is incompletely mounted, and the image with the container shutter closed. It is an object of the present invention to provide a toner replenishing mechanism capable of reliably preventing a forming operation and a color image forming apparatus including the toner replenishing mechanism.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a container shutter for opening and closing a toner replenishing port of a toner container containing replenishing toner, and a toner container mounted at a predetermined position in the image forming apparatus main body. A main body joint gear connected to the container shutter; a main body joint gear for holding the joint; and an urging means for urging the joint toward the container shutter side. A toner replenishment mechanism that opens and closes the toner replenishment port of the toner container by transmitting the rotation to the container shutter via the joint and rotating the container shutter.
A notch is formed in the outer periphery of the joint, and a rod that is in sliding contact with the outer periphery of the joint is interposed between the joint and the main body cover. When the container shutter of the toner container and the joint are normally connected, the rod The body cover is allowed to close by engaging with the notch on the outer periphery of the joint, and otherwise, the rod abuts against the body cover to prevent the body cover from being closed. It is characterized by that.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, urging means for urging the rod toward the body cover side is provided.

  According to a third aspect of the present invention, in the second aspect of the present invention, the biasing means includes at least a biasing force that opposes the weight of the rod.

  A color image forming apparatus according to a fourth aspect is capable of mounting a plurality of toner containers containing replenishing toners of different colors, and the toner replenishing mechanism according to any one of the first to third aspects is provided for each toner container. It is characterized by having.

  According to the first aspect of the present invention, when the container shutter of the toner container and the joint on the main body side are normally connected, the rod engages with the cut on the outer periphery of the joint and falls to allow the closing operation of the main body cover. In other cases, the rod is in contact with the main body cover so as to prevent the main body cover from being closed. Therefore, when the toner container is not completely installed, the user can be notified of this, and the container It is possible to reliably prevent the image forming operation with the shutter closed, and to stably supply toner from the toner container to the developing device.

  According to the second and third aspects of the invention, since the rod is urged toward the main body cover by the urging means, the rod engages with the notch on the outer periphery of the joint before loading the toner container into the apparatus main body. The closing operation of the main body cover in a state where the toner container is not completely mounted without being depressed is surely prevented.

  According to the fourth aspect of the present invention, since the image forming operation with the container shutter closed is reliably prevented, the toner is stably supplied from the toner container to the developing device. Can be formed stably.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Color image forming apparatus]
FIG. 1 is a front sectional view of a color image forming apparatus according to the present invention. The illustrated color image forming apparatus is a tandem type, and a magenta image forming unit 1M and a cyan image forming unit are formed in the center of the main body 100. The unit 1C, the yellow image forming unit 1Y, and the black image forming unit 1BK are arranged in tandem at regular intervals.

  Each of the image forming units 1M, 1C, 1Y, and 1BK is provided with photosensitive drums 2a, 2b, 2c, and 2d, which are image carriers, and a charger 3a is disposed around each of the photosensitive drums 2a to 2d. , 3b, 3c, 3d, developing devices 4a, 4b, 4c, 4d, transfer rollers 5a, 5b, 5c, 5d as transfer means, and drum cleaning devices 6a, 6b, 6c, 6d, respectively.

  Here, the photosensitive drums 2a to 2d are drum-shaped photosensitive members, and are rotationally driven at a predetermined process speed in the direction of the arrow (clockwise) by a motor (not shown). The chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d to a predetermined potential by a charging bias applied from a charging bias power source (not shown).

  Further, the developing devices 4a to 4d contain magenta (M) toner, cyan (C) toner, yellow (Y) toner, and black (BK) toner, respectively, and are formed on the respective photosensitive drums 2a to 2d. In addition, the toner of each color is attached to each electrostatic latent image to visualize each electrostatic latent image as a toner image of each color.

  The transfer rollers 5a to 5d as transfer means are disposed so as to be in contact with the photosensitive drums 2a to 2d via the intermediate transfer belt 7 in each primary transfer portion. Here, the intermediate transfer belt 7 is stretched between the secondary transfer counter roller 8 and the tension roller 9 and is disposed on the upper surface side of each of the photosensitive drums 2a to 2d. The roller 8 is disposed so as to be in contact with the secondary transfer roller 10 via the intermediate transfer belt 7 in the secondary transfer portion. A belt cleaning device 11 is provided in the vicinity of the tension roller 9. As a material for the intermediate transfer belt 7, for example, a dielectric resin such as polycarbonate, polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), or the like is selected.

  Incidentally, toner containers 12a, 12b, 12c and 12d for supplying toner to the developing devices 4a to 4d are arranged in a line above the image forming units 1M, 1C, 1Y and 1BK in the apparatus main body 100. It is installed.

  In addition, a laser scanner unit (LSU) 13 is disposed below the image forming units 1M, 1C, 1Y, and 1BK in the apparatus main body 100, and a paper feed cassette 14 is detachably attached to the bottom of the main body 100 below the image forming units. is set up. A plurality of sheets (not shown) are stacked and accommodated in the paper feed cassette 14, and a pickup roller 15 for taking out the paper one by one from the paper feed cassette 14 is taken out in the vicinity of the paper feed cassette 14. A feed roller 16 and a retard roller 17 are provided for feeding the fed paper to the transport path L.

  In addition, the conveyance path L extending in the vertical direction on the side of the apparatus main body 100 includes a conveyance roller pair 18 that conveys the sheet, and the secondary transfer counter roller 8 and the second transfer opposing roller 8 at a predetermined timing after the sheet is temporarily held. A registration roller pair 19 is provided to be supplied to a secondary transfer portion which is a contact portion with the next transfer roller 10. Next to the transport path L, another transport path L ′ used for forming an image on both sides of the sheet is formed, and a plurality of transport roller pairs 20 are appropriately used in the transport path L ′. Are provided at regular intervals.

  By the way, the conveyance path L arranged in the vertical direction on one side in the apparatus main body 100 extends to the paper discharge tray 21 provided on the upper surface of the apparatus main body 100, and the fixing device 22 and the discharge path are in the middle. A paper roller pair 23 and a paper discharge device 24 are provided.

  Next, an image forming operation by the color image forming apparatus having the above configuration will be described.

  When an image formation start signal is issued, the photosensitive drums 2a to 2d are driven to rotate at a predetermined process speed in the direction of the arrow in FIG. 1 (clockwise) in each of the image forming units 1M, 1C, 1Y, and 1BK. The drums 2a to 2d are uniformly charged by the chargers 3a to 3d. The laser scanner unit 13 emits a laser beam modulated by a color image signal for each color, irradiates the surface of each photosensitive drum 2a to 2d with the laser beam, and each color is applied to each photosensitive drum 2a to 2d. An electrostatic latent image corresponding to the color image signal is formed.

  First, magenta toner is attached to the electrostatic latent image formed on the photosensitive drum 2a of the magenta image forming unit 1M by the developing device 4a to which a developing bias having the same polarity as the charged polarity of the photosensitive drum 2a is applied. The electrostatic latent image is visualized as a magenta toner image. This magenta toner image is transferred to the arrow shown in FIG. 1 by the action of the transfer roller 5a to which a primary transfer bias having a polarity opposite to that of the toner is applied at the primary transfer portion (transfer nip portion) between the photosensitive drum 2a and the transfer roller 5a. Primary transfer is performed on the intermediate transfer belt 7 which is rotationally driven in the direction.

  The intermediate transfer belt 7 on which the magenta toner image has been primarily transferred as described above moves to the next cyan image forming unit 1C. In the cyan image forming unit 1C as well, the cyan toner image formed on the photosensitive drum 2b is transferred to the magenta toner image on the intermediate transfer belt 7 in the primary transfer portion in the same manner as described above.

  Similarly, yellow and black toners respectively formed on the photosensitive drums 2c and 2d of the yellow and black image forming units 1Y and 1BK on the magenta and cyan toner images superimposed and transferred on the intermediate transfer belt 7, respectively. The images are sequentially superimposed at each primary transfer portion, and a full-color toner image is formed on the intermediate transfer belt 7. The transfer residual toner which is not transferred onto the intermediate transfer belt 7 and remains on the photosensitive drums 2a to 2d is removed by the drum cleaning devices 6a to 6d, and the photosensitive drums 2a to 2d are prepared for the next image formation. It is done.

  Then, the pickup from the paper feed cassette 14 is performed in accordance with the timing at which the front end of the full color toner image on the intermediate transfer belt 7 reaches the secondary transfer portion (transfer nip portion) between the secondary transfer counter roller 8 and the secondary transfer roller 10. The sheet fed to the conveyance path L by the roller 15, the feed roller 16 and the retard roller 17 is conveyed to the secondary transfer unit by the registration roller pair 19. Then, a full-color toner image is collectively transferred from the intermediate transfer belt 7 to the sheet conveyed to the secondary transfer unit by the secondary transfer roller 10 to which a secondary transfer bias having a polarity opposite to that of the toner is applied. .

  Thus, the sheet on which the full-color toner image has been transferred is conveyed to the fixing device 22, and the sheet on which the full-color toner image has been fixed by being heated and pressurized and thermally fixed on the surface of the sheet. Then, the paper is conveyed to the paper discharge device 24 by the paper discharge roller pair 23 and is discharged onto the paper discharge tray 21 by the paper discharge device 24 to complete a series of image forming operations. The transfer residual toner that is not transferred onto the sheet and remains on the intermediate transfer belt 7 is removed by the belt cleaning device 11, and the intermediate transfer belt 7 is prepared for the next image formation.

[Toner supply mechanism]
Next, an embodiment of a toner replenishing mechanism according to the present invention will be described with reference to FIGS.

  2 is a partial perspective view of the toner container, FIG. 3 is a partial perspective view showing the relationship between the toner container and the main body joint gear, FIG. 4A is a partial perspective view showing the closed state of the container shutter, and FIG. Fig. 5 is a partial perspective view showing the open state of the container shutter, Fig. 5 is a perspective view of the main body side joint and spring and the main body joint gear, and Fig. 6A is a state where the container shutter of the toner container and the main body side joint are connected. FIG. 6B is an enlarged view of the main part of FIG. 6A, and FIG. 7A is a toner replenishing port when the container shutter of the toner container and the joint on the main body side are connected and rotated. FIG. 7B is an enlarged view of the main part of FIG. 7A, and FIG. 8 is a partial perspective view showing a state in which the top cover is closed after the toner supply port of the toner container is opened. 9A is a partial perspective view showing a state where the connection between the container shutter of the toner container and the joint is incomplete, FIG. 9B is an enlarged view of the main part of FIG. 9A, and FIG. FIG. 10 is a partial perspective view showing a state where the main body joint gear is rotated in a state where the coupling between the toner container and the joint is incomplete, FIG. 10B is an enlarged view of a main part of FIG. 10A, and FIG. FIGS. 12A and 12B are partial views of the main body of the image forming apparatus for explaining the interlocking mechanism of the opening / closing operation and the opening / closing operation of the toner supply opening of the toner container. FIGS. It is explanatory drawing of the interlocking mechanism which shows the opening / closing state of a replenishment port.

  Since the basic configurations of the toner containers 12a to 12d are the same, only the magenta toner container 12a will be described below.

  As shown in FIG. 4, a rectangular toner supply port 25 is opened on the bottom surface of the toner container 12 a, and the toner supply port 25 is opened and closed by a cylindrical container shutter 26. That is, the container shutter 26 is formed with a rectangular hole 26a having the same shape as the toner replenishing port 25, and the container shutter 26 rotates and the rectangular hole 26a selectively communicates with the toner replenishing port 25. 25 is opened and closed.

  As shown in FIG. 3, a coupling 27 having a fitting protrusion 27a is provided at the end of the container shutter 26, and a joint 28 is provided on the apparatus main body 100 side. The joint 28 is formed with a fitting recess 28a into which the fitting protrusion 27a of the coupling 27 is fitted.

  The joint 28 is slidably held in the axial direction (longitudinal direction of the toner container 12a) by the main body joint gear 29, and is a spring that is a biasing means that is contracted between the main joint gear 29 and the main body joint gear 29. 30 is biased toward the container shutter 26.

  Further, in the present embodiment, as shown in FIG. 8, a rod 31 whose lower end is in sliding contact with the outer periphery of the joint 28 is interposed between the joint 28 and the top cover 100a, and FIG. As shown in FIG. 3, a cut 28b is partially formed on the outer periphery of the joint 28.

  Thus, the toner container 12a is mounted by being dropped vertically into a predetermined location in the image forming apparatus main body 100 (see FIG. 1) with the toner supply port 25 closed by the container shutter 26. At this time, the fitting protrusion 27 a of the coupling 27 provided at the end of the container shutter 26 abuts on the joint 28 and pushes it into the body joint gear 29 against the urging force of the spring 30. When the fitting protrusion 27a of the coupling 27 is fitted into the fitting recess 28a of the joint 28 and the coupling 27 (container shutter 26) and the joint 28 are normally connected, the joint 28 is attached to the spring 30. It is pushed by the force and pops out from the main body joint gear 29 as shown in FIG.

  In the above state, the lower end of the rod 31 is in contact with a portion other than the notch 28b on the outer periphery of the joint 28 as shown in FIG. 6, but when the top cover 100a shown in FIG. 8 is closed, the top cover 100a is closed. The main body joint gear 29 rotates in the direction of the arrow in FIG. 7B in conjunction with the operation, and the joint 28 rotates together with the main body joint gear 29 to expose the notches 28b formed on the outer periphery thereof. Then, as shown in FIG. 7, the lower end of the rod 31 is engaged with the notch 28b of the joint 28 and falls, so that the rod 31 moves downward and the rod 31 does not protrude above the top cover 100a. For this reason, the top cover 100a can be normally closed as shown in FIG.

  On the other hand, when the coupling 27 (container shutter 26) and the joint 28 are not normally connected when the toner container 12a is mounted, the joint 28 enters the inside of the main body joint gear 29 as shown in FIG. In this state, the main body joint gear 29 rotates in the direction of the arrow in FIG. 10B in conjunction with the closing operation of the top cover 100a, and the joint 28 rotates in the same direction. Since the notch 28b formed on the outer periphery of the joint 28 enters the inside of the main body joint gear 29 and is not exposed to the outside, the rod 31 does not fall and the top cover 100a can be completely closed by interference with the rod 31. Can not. Therefore, this allows the user to know that the toner container 12a is not completely installed. As a result, it is possible to reliably prevent the occurrence of an image forming operation with the container shutter 26 closed, and to stably supply toner from the toner container 12a to the developing device 4a (see FIG. 1). Done.

  Here, a mechanism (interlocking mechanism) in which the toner replenishing port 25 of each of the toner containers 12a to 12d is opened and closed in conjunction with the opening and closing operation of the top cover 100a will be described with reference to FIGS. 11, 12A, and 12B. To do.

  As shown in FIG. 11, a rack member 32 is provided in the upper part of the apparatus main body 100 so as to be movable in the horizontal direction (in the direction of the arrow). Each of the four racks 32a formed on the lower surface of the rack member 32 has each toner. Main body joint gears 29 corresponding to the containers 12a to 12d are engaged with each other.

  On the other hand, a sector-shaped sector gear 34 is attached to the fulcrum shaft 33 of the top cover 100a, and the sector gear 34 meshes with a pinion gear 36 through an idle gear 35. The pinion gear 36 meshes with a rack 32 b formed on the upper surface of one end in the longitudinal direction of the rack member 32.

  Thus, when the top cover 100a is rotated about the fulcrum shaft 33 to open and close, the rack member 32 reciprocates in the horizontal direction, and the main body joint gear 29 that meshes with the four racks 32a formed thereon rotates. This rotation is transmitted to the container shutter 26 of each of the toner containers 12a to 12d via the joint 28 and the coupling 27, and the container shutter 26 rotates to open and close the toner supply port 25.

  That is, when the top cover 100a is closed, as shown in FIG. 12A, the fulcrum shaft 33 and the sector gear 34 coupled thereto rotate in the direction of the arrow, and the rotation is transmitted to the pinion gear 36 via the idle gear 35. Then, since the pinion gear 36 rotates in the direction of the arrow, the rack member 32 that meshes with the rack 32b moves in the direction of the arrow. When the rack member 32 moves in the arrow direction, the four main body joint gears 29 meshing with the rack 23a of the rack member 32 rotate in the arrow direction, so that the container shutters 26 of the toner containers 12a to 12d rotate in the same direction. As the container shutter 26 rotates in this manner, the toner supply ports 25 of the toner containers 12a to 12d are opened.

  Then, when the top cover 100a is rotated upward about the fulcrum shaft 33 from the closed state shown in FIG. 12 (a) and opened, the fulcrum shaft 33 and the fulcrum shaft 33 are connected to the fulcrum shaft 33 as shown in FIG. 12 (b). The worn sector gear 34 rotates in the direction of the arrow, and the rotation is transmitted to the pinion gear 36 through the idle gear 35. The pinion gear 36 rotates in the direction of the arrow, so that the rack member 32 meshed with the rack 32b moves in the direction of the arrow. Move to. When the rack member 32 moves in the arrow direction, the four main body joint gears 29 meshing with the rack 23a of the rack member 32 rotate in the arrow direction, so that the container shutters 26 of the toner containers 12a to 12d rotate in the same direction. Then, the toner supply ports 25 of the toner containers 12a to 12d are closed by the container shutter 26.

  As described above, the toner supply ports 25 of the toner containers 12a to 12d are opened and closed in conjunction with the opening and closing operation of the top cover 100a.

  Although only the magenta toner container 12a has been described above, the rods 31 are also provided for the other toner containers 12b to 12d, respectively, so that all the toner containers 12a to 12d are not mounted normally. Since the cover 100a cannot be completely closed, the user can know that all the toner containers 12a to 12d have been normally mounted when the top cover 100a is completely closed.

  By the way, as described above, for example, the toner container 12a is mounted by being dropped vertically into a predetermined position in the image forming apparatus main body 100 (see FIG. 1) in a state where the toner supply port 25 is closed by the container shutter 26. However, for some reason before the toner container 12a is loaded into the image forming apparatus main body 100 (for example, as a result of the toner container 12a being loaded in an inclined state as shown in FIG. 13). As a result, the lower end of the rod 31 is engaged with the notch 28b of the joint 28 as shown in FIG. 7, and the rod 31 is depressed as shown in FIG.

  More specifically, as shown in FIG. 13, when the toner container 12 a is loaded into the image forming apparatus main body 100 obliquely from above, when the top cover 100 a starts to be closed from this state, the main body on the image forming apparatus main body 100 side. The joint gear 29 rotates, and a cut 28a formed on the outer periphery of the joint 28 that rotates with the joint gear 29 appears. When the top cover 100a is further closed, the rod 31 falls by its own weight at a certain timing and engages with the cut 28a of the joint 28. In this state, the rod 31 does not interfere with the top cover 100a. Therefore, when the top cover 100a is further closed, the top cover 100a comes into contact with the upper surface of the toner container 12a and forcibly pushes the toner container 12a. The resin housing of the forming apparatus main body 100 is elastically deformed, and the top cover 100a is completely closed even when the toner container 12a is not normally loaded.

  In the above state, the toner replenishing port 25 of the toner container 12a remains closed. However, since the rod 31 is depressed at this time, the top cover 100a is allowed to close. Therefore, there is a possibility that the top cover 100a is closed even when the toner supply port 25 of the toner container 12a is closed.

  As a countermeasure against the above problem, as shown in FIG. 14, a torsion coil spring 37 as an urging means is provided on the image forming apparatus main body 100 side, and the torsion coil spring 37 constantly urges the rod 31 upward (to the top cover 100a side). The structure which performs is considered. When such a configuration is adopted, the rod 31 does not fall by engaging with the notch 28b of the joint 28 unless the top 31 is pushed down by the top cover 100a when the top cover 100a is closed. Therefore, when the toner container 12a is loaded into the image forming apparatus main body 100, the coupling 27 and the joint 28 are always securely connected. When the top cover 100a is closed, the toner in the toner container 12a is interlocked with the operation. The supply port 25 is reliably opened by the container shutter 26. Therefore, even when the toner supply port 25 of the toner container 12a is closed, the problem that the top cover 100a is closed can be reliably prevented. Here, it is sufficient that the torsion coil spring 37 has at least an urging force that opposes the own weight of the rod 31, and it is necessary to prevent the rod 31 from dropping by the urging force of the torsion coil spring 37.

  In the above description, the present invention has been described with respect to a full-color laser beam printer and a toner replenishment mechanism provided therein. However, the present invention is not limited to any color printer or color copier. Of course, the present invention can be similarly applied to the image forming apparatus and the toner replenishing mechanism provided therein.

1 is a front sectional view of a color image forming apparatus according to the present invention. FIG. 4 is a partial perspective view of a toner container of the toner supply mechanism according to the present invention. FIG. 6 is a partial perspective view illustrating a relationship between a toner container and a main body joint gear of the toner supply mechanism according to the present invention. (A) is a partial perspective view showing the closed state of the container shutter of the toner replenishing mechanism according to the present invention, and (b) is a partial perspective view showing the opened state of the container shutter. FIG. 4 is a perspective view of a main body side joint, a spring, and a main body joint gear of the toner supply mechanism according to the present invention. (A) is a fragmentary perspective view which shows the state which the container shutter of the toner container of the toner replenishing mechanism concerning this invention and the joint of the main body side were connected, (b) is a principal part enlarged view of (a). (A) is a partial perspective view showing a state in which a toner replenishing port opens when a container shutter of a toner container of a toner replenishing mechanism according to the present invention and a joint on the main body side are connected and rotated, and (b) is a perspective view of (a). It is a principal part enlarged view. FIG. 4 is a partial perspective view showing a state in which a top cover is closed after a toner supply port of a toner container of a toner supply mechanism according to the present invention is opened. (A) is a partial perspective view showing a state where the connection between the container shutter and the joint of the toner container of the toner replenishing mechanism according to the present invention is incomplete, and (b) is an enlarged view of the main part of (a). (A) is a partial perspective view showing a state where the main body joint gear is rotated in a state where the connection between the toner container and the joint of the toner replenishing mechanism according to the present invention is incomplete, and (b) is an enlarged view of the main part of (a). It is. FIG. 6 is a partial view of the main body of the image forming apparatus for explaining the interlocking mechanism of the opening / closing operation of the top cover and the opening / closing operation of the toner supply port of the toner container. (A), (b) is explanatory drawing of the interlock mechanism which shows the open / close state of the toner supply port of the toner container in the top cover closed state and the top cover open state. FIG. 6 is a perspective view illustrating a state in which a toner container is loaded in an inclined state. It is a perspective view which shows the structure which urges | biases a rod upward by a torsion coil spring.

Explanation of symbols

1M Magenta image forming unit 1C Cyan image forming unit 1Y Yellow image forming unit 1BK Black image forming unit 2a to 2d Photosensitive drum (photoconductor)
3a to 3d charger 4a to 4d developing device 5a to 5d transfer roller 6a to 6d drum cleaning device 7 intermediate transfer belt 8 secondary transfer counter roller 9 tension roller 10 secondary transfer roller 11 belt cleaning device 12a to 12d toner container 13 laser Scanner unit (LSU)
DESCRIPTION OF SYMBOLS 14 Paper feed cassette 15 Pickup roller 16 Feed roller 17 Retard roller 18 Conveyance roller pair 19 Registration roller pair 20 Conveyance roller pair 21 Paper discharge tray 22 Fixing device 23 Paper discharge roller pair 24 Paper discharge device 25 Toner supply port 26 Container shutter 26a Container Rectangular hole of shutter 27 Coupling 27a Coupling fitting projection 28 Joint 28a Joint fitting recess 28b Joint cut 29 Body joint gear 30 Spring (biasing means)
31 Rod 32 Rack member 32a, 32b Rack 33 Support shaft of top cover 34 Sector gear 35 Idle gear 36 Pinion gear 37 Torsion coil spring (biasing means)
100 Image forming apparatus main body 100a Top cover (main body cover)
L, L 'transport path

Claims (4)

A container shutter that opens and closes a toner replenishing port of a toner container that contains replenishing toner, a joint that is connected to the container shutter when the toner container is mounted at a predetermined position in the main body of the image forming apparatus, and holds the joint A main body joint gear, and biasing means for biasing the joint toward the container shutter; the main body joint gear is rotated in conjunction with an opening / closing operation of the main body cover; and the rotation of the main body joint gear is performed via the joint. A toner replenishing mechanism that opens and closes the toner replenishing port of the toner container by rotating the container shutter.
A notch is formed in the outer periphery of the joint, and a rod that is in sliding contact with the outer periphery of the joint is interposed between the joint and the main body cover. When the container shutter of the toner container and the joint are normally connected, the rod The body cover is allowed to close by engaging with the notch on the outer periphery of the joint, and otherwise, the rod abuts against the body cover to prevent the body cover from being closed. A toner replenishment mechanism characterized by the above.   The toner replenishing mechanism according to claim 1, further comprising an urging unit that urges the rod toward the main body cover.   The toner replenishing mechanism according to claim 2, wherein the urging unit includes an urging force that opposes at least the weight of the rod. A color image forming apparatus, wherein a plurality of toner containers containing replenishing toners of different colors can be mounted, and the toner replenishing mechanism according to any one of claims 1 to 3 is provided for each toner container. .

Images