JP2005308906A - Image forming apparatus and developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary type developing device constituted so that a toner container can be replaced separately from a developing unit, where new toner and old toner are not mixed even by the rotation of a rotary rack, the new toner is supplied to the developing unit only at a necessary time and deteriorated toner is discharged when the toner container is replaced. <P>SOLUTION: The toner container and the developing unit are provided with openings for moving the toner between the toner container and the developing unit, and shutters constituted to slide in an opening/closing direction by possessing a means biased in a closing direction at ordinary time at the respective openings and opened/closed interlocked with the rotation of the rotary type rack at a position where they come into contact with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method, and more particularly, to a cylindrical rotary rack configured to be rotatable, a developing roller, The present invention relates to a developing device in a rotary type image forming apparatus in which a developing device provided with a supply roller and a toner container are supported for the number of colors to be used, and each developing roller is sequentially opposed to an image carrier.

  A developing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method does not use a two-component developing method in which a toner and a carrier are used as a developer. A one-component developing system using only toner is known.

  In a one-component developing type developing device, toner contained in the main body of the device is fed to the surface of the developing roller by a supply roller, and a regulating member is pressed against the developing roller to regulate the amount of toner and frictionally charge the developing roller. To rotate the toner to the developing area facing the image carrier to develop the electrostatic latent image formed on the image carrier, and the toner remaining on the surface of the developing roller is separated from the surface of the developing roller by the supply roller. At the same time, new toner is supplied to the developing roller.

  However, when the regulating member is pressed against the surface of the developing roller to regulate the amount of toner conveyed by the developing roller, the toner having a large particle size is separated from the developing roller and the toner having the small particle size is first developed. Even when the toner remaining on the developing roller after development is released, the toner having a large particle size is released from the developing roller, and the particle size gradually increases in the developing device. There is a problem that the ratio of large toner increases and the image quality of the formed image decreases.

  Therefore, a partition is provided between the developing unit provided with the supply roller and the developing roller in the developing device and the toner storage unit, or the developer container and the toner container storing the toner are separated. A developing device is used in which an opening is provided at a position where the toner container comes into contact with the toner container so that the toner separated from the developing roller does not return to the toner container or the toner container.

  On the other hand, in a color image forming apparatus, a developing device for the number of colors used in such a color image forming apparatus using a one-component developer is supported by a cylindrical rotary rack configured to be rotatable, and A rotary type developing device is used in which the developing roller of the developing unit corresponding to the color is made to sequentially face the image carrier.

  When a one-component development method is used in such a rotary type developing device, there is no need to change the carrier, so that a developing roller that develops a latent image facing the photosensitive member (image carrier) or toner is applied to the developing roller. Constituent members such as supply rollers, supply blades for supply, and regulation blades that charge the toner to a predetermined charge amount, and consumable toner are contained in an integrated development cartridge. When the toner runs out, the development toner Means for exchanging the cartridge itself is adopted, and this method has an advantage that the maintainability is improved.

  However, in this method, the toner can be used even when the developing roller in the developing unit, the supply roller for supplying the toner to the developing roller, the supply blade, and the regulating blade for charging the toner to a predetermined charge amount are still usable. If it disappears, it will have to be replaced | exchanged, and it will be expensive to replace even if it is unnecessary from a user's viewpoint. In other words, it imposes an extra cost burden on the user, and also generates extra man-hours in the collection, disposal, and recycling of the developer cartridge, and is not necessarily an excellent method from the viewpoint of environmental protection. hard.

  Further, in the rotary type developing device, even if a partition is provided or the developing device and the toner container are separated, the rotary rack rotates to change the vertical relationship between the developing device and the toner container, resulting in excessive toner supply. , Fogging occurs, toner having a large particle size in the developing unit is returned to the toner container or toner container, and the effect of separating the developing unit and the toner container is lost. There remains a problem that only a small toner is used for development first, and a toner having a large particle size remains, and the image quality of the formed image gradually deteriorates.

  On the other hand, when the developing device is rotated, there is a toner that is partially accumulated and not used and is not discharged, and the toner container is empty and contains a new toner. When the container is replaced, new toner and deteriorated toner whose adhesion state of the external additive has changed are mixed, resulting in a problem that charging failure occurs and image quality is lowered.

  In order to cope with these problems, Patent Document 1 discloses that a toner container that rotates integrally with the rotary is arranged outside the developing unit constituent member in the axial direction of the rotary developing device so that only the toner container can be replaced. In addition, there is shown a developing device in which only a necessary amount of toner is fed into a developing device by an axial conveying member. Further, in Patent Document 2, in a rotary type developing device, a toner container is disposed adjacent to a developing device in a replaceable manner, and is replenished from the toner container to the developing device through a replenishing port using a conveying member such as a screw. In addition, a developing device configured to convey toner from the developing device to the toner container is shown in order to prevent the toner from being oversupplied to the developing device as the rotary rotates.

JP-A-7-114260 JP-A-10-149012

  However, the developing device disclosed in Patent Document 1 can supply only a necessary amount of toner to the developing device and can replace only the toner container. However, an axial conveying member is necessary and a rotary shaft corresponding to the toner container is required. When the direction becomes longer, the developing unit cannot be reduced in size, and as a result, the machine itself becomes larger, and it is difficult to say that the construction is inexpensive if a means for detecting the toner amount of the developing unit is required and a driving unit is included.

  Further, the developing device disclosed in Patent Document 2 can be shortened in the axial direction but has a conveying member, so that the rotary diameter is increased and toner is supplied in the axial direction. .

  Therefore, according to the present invention, in the rotary type developing apparatus in which the toner container can be replaced separately from the developing unit, the supply of new toner for replenishment and the inside of the developing unit is not caused by the rotation of the rotary rack. Provided a developing device in a rotary type image forming apparatus that can supply a new toner to a developing device only when necessary without being mixed with toner, and can discharge a deteriorated toner when replacing a toner container, and can be made compact. It is a problem to do.

In order to solve the above problems, in the present invention,
A cylindrical rotary rack having an image carrier that carries a latent image, a developing roller that develops the latent image on the image carrier, and a supply roller that carries toner to the developing roller, and is configured to be rotatable. A plurality of developing units that are fixedly moved by the rotation of the rotary type rack to sequentially move the developing roller to a position facing the image carrier, and the rotary type rack or the developing unit adjacent to the developing units; In a developing device in a rotary type image forming apparatus comprising a toner container detachably supported,
The toner container and the developing unit are opened and closed with an opening for moving the toner between the toner container and the developing unit at a position where the toner container and the developing unit are in contact with each other, and a means that is normally urged in the closing direction. The shutter is configured to be slidable in the direction and is opened and closed in conjunction with the rotation of the rotary rack.

  The center of the opening in the toner container and the developing unit is at a position at least equal to or lower than the axis of the supply roller at a position where the developing roller in the developing unit faces the image carrier. Features.

  The shutter may be forcibly opened at a toner supply angle position where the toner moves from the toner container to the developing device and a toner discharge angle position where the toner moves from the developing device to the toner container. .

  The means for forcibly opening the shutter at the toner supply angle position includes a convex portion provided on the image forming apparatus main body side in a circumferential direction from an angle position at which the shutter is opened to an angle position at which the shutter is closed, and the shutter. And a mechanism for sliding the shutter in the opening direction against the urging means by contacting the convex portion.

  Further, a means for forcibly opening the shutter in the toner container and the developing device at the toner discharge angle position is provided at a toner discharge angle position on the image forming apparatus main body side, and is configured to protrude when the toner is discharged; It is a mechanism that is provided at an end of the shutter and that slides the shutter in the opening direction against the urging means by contacting the stopper.

  As described above, the developing device is fixed to the rotary rack and the toner container is detachably supported, and the opening for moving the toner between the toner container and the developing device is provided at a position where the toner container and the developing device are in contact with each other. And a shutter configured to be slidable in the opening / closing direction and having a means that is normally urged in the closing direction at each of the openings, and a shutter that opens / closes in conjunction with the rotation of the rotary rack The opening and closing timing of the shutter is set so that the new toner can be replenished to the developing device without mixing the new toner for replenishment with the toner in the developing device even by rotation of the rotary rack, and the toner container. By setting the time when the deteriorated toner can be discharged into the toner container at the time of replacement, the new toner and the toner in the developing device are mixed. Since the deteriorated toner can be discharged when the toner container is replaced, and the mechanism is simply provided with an opening and a shutter, the rotary axis direction becomes longer by the amount corresponding to the toner container as in the conventional device, It is possible to provide a developing device in a rotary type image forming apparatus that does not require an axial conveying member and a means for detecting the toner amount of the developing device, and can make the image forming apparatus small as much.

  The center of the opening in the toner container and the developing unit is at a position that is at least the same height or lower than the axis of the supply roller at a position where the developing roller in the developing unit faces the image carrier. For example, when the opening position of the shutter for supplying toner from the toner container to the developing device is set to a position rotated from the position where the developing roller and the image carrier face each other to the lower side of the image carrier, supply Since the toner reservoir space between the roller and the opening does not become so large, there is no excessive supply or insufficient supply of toner from the toner container, and an appropriate amount of toner is always held in the developing device. Become.

  Further, a rotary rack is provided by means for forcibly opening the shutter at a toner supply angle position where the toner moves from the toner container to the developing device and a toner discharge angle position where the toner moves from the developing device to the toner container. Rotation of the toner does not cause oversupply or supply shortage, new toner for replenishment and toner in the developer unit are not mixed, and new toner can be supplied to the developer only when necessary, and deteriorated toner can be supplied to the toner. It is possible to provide a developing device in a rotary type image forming apparatus that can be discharged at the time of container replacement.

  The means for forcibly opening the shutter at the toner supply angle position is a convex portion provided on the image forming apparatus main body side in a circumferential direction from the angle position at which the shutter is opened to the angle position at which the shutter is closed. The means for forcibly opening the shutter in the toner container and the developing device at the discharge angle position is a stopper provided at the toner discharge angle position on the image forming apparatus main body side and protruding when the toner is discharged, and the shutter Has a mechanism that slides the shutter in the opening direction against the urging means by abutting against the convex portion or stopper at its end, so that the non-developing angle position and the toner container can be replaced with a very simple configuration. Easily and reliably open and close the shutter at the angular position to replenish new toner and discharge deteriorated toner It can be.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  FIG. 1 is a diagram showing a schematic configuration of a developing device in the image forming apparatus of the present invention. FIG. 2 is a diagram showing a configuration of a toner container and a developing device of the developing device in the image forming apparatus of the present invention. FIG. 5 is a diagram for explaining a shutter opening / closing mechanism between the toner container and the developing device when toner is supplied from the toner container to the developing device, and FIG. 5 is a diagram illustrating shutter opening / closing timing and toner supplying operation from the toner container to the developing device. FIG. 6 is a diagram for explaining a method of discharging deteriorated toner in the developing device, FIG. 7 is an illustration of a shutter opening / closing mechanism when discharging the deteriorated toner, and FIG. 8 is an image formation having the developing device of the present invention. It is sectional drawing which showed the structure outline of the apparatus.

In the drawings, the same constituent elements are denoted by the same reference numerals. Reference numeral 1 denotes an image forming apparatus having a rotary type developing device 2 according to the present invention. Reference numeral 2 denotes black (B) 3 ₁ used for color image formation, for example, magenta ( M) 3 ₂ , cyan (C) 3 ₃ , yellow (Y) 3 ₄ toner containers 3, and black (B) 4 ₁ , magenta (M) 4 ₂ , cyan (C) corresponding to the respective toner containers. 4 ₃ and a yellow (Y) 4 ₄ developing device 4, which is a rotary type developing device, in which the developing device 4 of each color is sequentially transferred to a photosensitive member (image carrier) 5. The latent image on the photosensitive member (image bearing member) 5 is developed by rotating it so that the developing position is opposite to the developing member. 6 is a charging device, 7 is an exposure device using a laser, for example, 8 is a cleaning device, 9 is an intermediate transfer belt, 10 is a primary transfer roller, 11 is a secondary transfer roller, 12 is a recording medium conveyance path, and 13 is fixing. 14 is a discharge unit, 15 is a cleaning device for the intermediate transfer belt 9, 16 is a recording medium, 20 is a cylindrical rack constituting the rotary developing device 2 of the present invention, 30 is an opening on the toner container side, and 31 is a toner container. The side shutter, 40 is a developing roller that constitutes the developing device 4 and carries toner, 41 is a supply roller that is made of urethane sponge or the like that supplies toner to the developing roller 40, and 42 is the toner layer thickness on the developing roller 40 And a regulating blade 43 that charges the toner and 43 is a pressing member for pressing the seal member 44 against the developing roller 40, such as urethane sponge. Used. 45 is an opening on the developing unit 4 side, 46 is a developing unit side shutter, 50A, 50B, 50C, and 50D are toner container side toners, 51A, 51B, 51C, and 51D are developing unit side toners, 70 is a plunger, 71 is a spring, Reference numeral 72 denotes a stopper, 73 denotes a shaft of the stopper 72, and 74 denotes deteriorated toner.

First, referring to FIG. 8, the image forming operation of the image forming apparatus 1 having the rotary developing device 2 according to the present invention will be briefly described. In the standby state, for example, black (B ) for the developing device 4 ₁ is such that a developing position facing the photosensitive member (image bearing member) 5. When image data is sent to a control device (not shown), the image data is decomposed into data of each color of black (B), magenta (M), cyan (C), and yellow (Y). The photoreceptor (image carrier) 5 is uniformly charged by the charging device 6.

The first black (B) data is exposed photosensitive member (image bearing member) 5 is given to the exposure device 7, when the latent image is formed it becomes developed toner image by the developing device 4 _1, The toner image is transferred to the intermediate transfer belt 9 by the primary transfer roller 10 to which a primary transfer bias is applied. The residual toner remaining after the formed toner image is transferred to the intermediate transfer belt 9 is cleaned by the cleaning device 8, and the next image formation is performed. The secondary transfer roller 11 and the cleaning device 15 that are in contact with the intermediate transfer belt 9 are separated from the intermediate transfer belt 9 until the toner images of all colors are transferred onto the intermediate transfer belt 9 in an overlapping manner. .

Thus After completion of the formation of the toner image of black (B) to rotate the rotary type developing device 2, a developing device 4 ₂ of the following magenta (M) is a developing position facing the photosensitive member (image bearing member) 5, The previously decomposed magenta (M) image data is given to the exposure device 7 for exposure. And it latent image is formed on 5 the photosensitive member (image bearing member) is developed by the developing device 4 ₂ becomes a toner image, on the black toner image being transferred onto the intermediate transfer belt 9 (B) Are superimposed and transferred.

  The same operation is repeated with cyan (C) and yellow (Y) image data, and when all color toner images are transferred to the intermediate transfer belt 9 to form a full-color toner image, the intermediate transfer belt 9 first. The secondary transfer roller 11 and the cleaning device 15 that are separated from each other are brought into contact with the intermediate transfer belt 9, and the recording medium 16 is sent through the recording medium conveyance path 12 to the secondary transfer position where the secondary transfer roller 11 is positioned. Thus, the full color toner image is transferred to the recording medium 16.

  The recording medium 16 onto which the full color toner image has been transferred in this manner is further sent to the fixing device 13 where it is fixed by heat and pressure, and is discharged to the discharge unit 14. The residual toner remaining on the intermediate transfer belt 9 is cleaned by the cleaning device 15 and prepared for the next image formation.

The rotary developing device 2 in such an image forming apparatus of the present invention is schematically shown in FIG. 1, and FIG. 2 shows the configuration of each of the toner container 3 and the developing device 4 constituting the developing device. , black cylindrical rack 20 in a rotary type developing device 2 (B) _{4 1,} magenta (M) _{4 2,} cyan (C) _{4 3,} yellow (Y) ₄ developing units 4 of ₄ is fixed, the Adjacent to each developing device 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ , a toner container 3 of black (B) 3 ₁ , magenta (M) 3 ₂ , cyan (C) 3 ₃ , yellow (Y) 3 ₄ Are detachably supported by the cylindrical rack 20 or the developing devices 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ by positioning members and coupling members (not shown).

The toner containers 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ of each color can be replaced from the top by opening the upper cover of the image forming apparatus 1 at a position where toner does not spill, and only at predetermined positions. A coupling member (not shown) is fixed by a stopper member linked to the rotary rotation position so as to be detachable.

Each developing device 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ has a developing roller 40, a supply roller 41 that supplies one-component toner to the developing roller 40, and a toner layer on the developing roller 40 that is biased by the developing roller 40. A metal regulating blade 42 that regulates the thickness and charges the toner, a seal member 44 that is pressed against the developing roller 40 by a pressing member 43 so that the toner does not leak to the outside, and the like are developed by the regulating blade 42. The toner amount on the roller 40 is equalized to a predetermined amount, and the toner is attached to the latent image by a bias potential at a position close to the photoreceptor (image carrier) 5.

  The toner container 3 and the developing unit 4 have openings 30 (toner container 3 side) and 45 (developing unit 4) for supplying toner from the toner container 3 when the toner in the developing unit 4 is consumed and decreases. Furthermore, shutters 31 and 46 are provided in the openings 30 and 45 so that the toner does not spill when the toner container 3 is attached and detached.

The toner containers 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ and the developing devices 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ are moved to the developing positions shown in FIG. 1 and ₃ 2, _{4 2} position) in FIG. 8, (B), (toner supply angular position shown in C) (in FIGS. 1 and 8 ₃ 2, _{4 2} position ₃ 1, _{4 1} To the first development position (A) after passing through the state shown in (D) (positions on the way from 3 ₁ , 4 ₁ to 3 ₂ , 4 ₂ in FIGS. 1 and 8). Return. In each state, the toner in the toner containers 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ and the toner in the developing devices 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ are changed to 50A from (A) to (D). , 50B, 50C, 50D, and 51A, 51B, 51C, 51D.

  That is, in the developing position shown in FIG. 5A, the toner in the toner container 3 and the developing device 4 is in the state shown in 50A and 51A, respectively, and the opening 30 in the toner container 3 and the developing device 4 A large amount of toner exists around 45, and it is difficult to move the toner from the toner container 3 to the developing device 4 side. However, as described above, when the shutters 31 and 46 are opened in this state, the toner having a large particle diameter in the developing device 4 is returned to the toner container 3, and the effect of separating the developing device 4 and the toner container 3 is lost. As a result, only the toner having a small particle size is used for the development first, and the toner having a large particle size remains, so that the image quality of the formed image gradually deteriorates.

Next, FIG. 5B is a position on the way from 3 ₂ , 4 ₂ to 3 ₁ , 4 ₁ in FIGS. 1 and 8 as described above, but the toner container 3 and the developing device 4. Are opened above the developing device 4 and if the toner 51B in the developing device 4 is used and there is a space in the developing device 4 where toner can be replenished, the toner container 3 is opened by opening the shutters 31 and 46. New toner can be fed into the developing device 4. However, FIG. 5B shows, as an example, a state in which the toner in the developing device 4 is not consumed so much that a large amount of toner 51B exists in the developing device 4 and the openings 30 and 45. Even if the shutters 31 and 46 are opened in this state, the toner does not move to the developing device 4 side, and the deteriorated toner in the developing device 4 does not move to the toner container 3 side.

On the other hand, FIG. 5 (C) is also a position in the middle from 3 ₂ , 4 ₂ position to 3 ₁ , 4 ₁ in FIG. 1 and FIG. Although the consumed state is shown, the toner 51C in the developing device 4 has some gaps in the vicinity of the openings 30 and 45, and when the shutters 31 and 46 are opened in this state, the toner is on the developing device 4 side. Move to. That is, if toner is replenished into the developing device 4 in the state of FIG. 5C, new toner is replenished with some gaps shown in FIG. Can be prevented from being oversupplied.

  That is, the center of the openings 30 and 45 in the toner container 3 and the developing device 4 is at least from the axis of the supply roller 41 at the position in FIG. 5A where the developing roller 40 in the developing device 4 faces the image carrier 5. If the position is at the same height or below, even if a space without toner is formed above the supply roller 41 as shown in FIG. 5C, a toner pool can be formed near the openings 30 and 45. Even if the shutters 31 and 46 are opened, the amount of toner that moves is not so much. Therefore, the toner-free space above the supply roller 41 is not filled with toner, and toner oversupply can be prevented. An appropriate amount of toner is always held in the developing device 4.

The last state shown in FIG. 5D is a position on the way from positions 3 ₁ , 4 ₁ to 3 ₂ , 4 ₂ in FIGS. 1 and 8 as described above. The gap slightly left in the developer 4 shown in the figure moves to the vicinity of the openings 30 and 45, and when the shutters 31 and 46 are opened in this state, the toner is filled in this space on the developer 4 side, and the developer 4 There is a possibility that the voids are completely eliminated and the toner is excessively replenished. Therefore, in the present invention, the shutters 31 and 46 are opened at the midway positions from 3 ₂ and 4 ₂ to 3 ₁ and 4 ₁ in FIGS. 1 and 8 in FIGS. 5B and 5C. A toner supply position for supplying toner into the developing device 4 was set.

Meanwhile the shutter 31, 46 is in the 3 _2, 4 ₂ development position in FIGS. 1 and 8 as shown in FIG. 3, arrows 32 slidably in the opening and closing direction (in the direction is different at other locations) The shutter 31 for the toner container 3 is normally closed by an urging means (not shown), and an example for opening and closing the shutter at one end or both ends in the rotary axis direction is shown in FIG. As shown in FIG. 4, a holding member 35 for holding a guide shaft 34 is further attached to a rod-like member 33 attached to the shutter 31, and a projection 37 that can be moved left and right in the figure by a spring 36 that passes through the guide shaft 34. Is provided. The shutter 31 for the toner container 3 is provided with a convex portion. When the toner container 3 is mounted, the convex portion of the shutter 31 on the toner container 3 side is in the concave portion provided on the shutter 46 on the developing device 4 side. Are fitted, and both shutters can be opened and closed in conjunction with each other. The shapes of the shutters 31 and 46 and the shapes of the openings 30 and 45 are not limited to squares, but both may be configured in a lattice shape and communicated by sliding in the axial direction.

  The shutters 31 and 46 are opened and closed when the developing device 4 shown in FIGS. 5B and 5C is rotated to the toner supply angle position. , (C) is provided with a convex portion formed along the rotation locus of the projection 37 as shown by 38 in FIG. 3 at a position corresponding to the position shown in FIG. The provided projection 37 abuts against the convex portion 38 as shown in FIG. 4A by the rotation of the rotary type developing device 2, and resists the spring 36 by further rotation as shown in FIG. 4B. Then, the shutter 31 is pushed toward the holding member 35, whereby the shutter 31 is pushed up and rides on the convex portion 38 to open the shutters 31 and 46. Therefore, the openings 30 and 45 are opened so that the toner can move. When the projections 38 are finished, the projection 37 returns to the original position and the shutters 31 and 46 are closed.

On the other hand, when the rotary developing device 2 rotates and the toner container 3 and the developing device 4 come to the positions 3 ₃ , 4 ₃ in FIGS. 1 and 8, the image forming apparatus 1 is not shown as described above. The toner container 3 can be replaced by opening the upper cover. Therefore, when a signal is received that any one of the toner containers 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ of each color is empty, the control device (not shown) rotates the rotary rack 20 to empty it. The resulting toner container 3 is positioned at 3 ₃ , 4 ₃ in FIG.

  Then, on the image forming apparatus main body 1 side on the way to the toner container replacement position, the plunger 70 is operated by a signal from a control device (not shown), and the shutter 31 is provided against the spring 71 by the operation of the plunger 70. A stopper 72 that locks the rod-shaped member 33 is provided so as to rotate about a shaft 73, and when the stopper 72 locks the rod-shaped member 33, the shutters 31 and 46 are opened.

Therefore, taken in a position empty toner container 3 is shown in FIG. 6 of the way to the toner container exchange position of 3 ₃ of FIG. 1 and FIG. 8 is rotated, the shutter 31, 46 is opened the rotary type developing device 2 is temporarily stopped, and the deteriorated toner 74 staying in the developing device 4 without being used is collected on the toner container 3 side. Thereafter, the control device (not shown) returns the plunger 70 to its original state. The rotary developing device 2 is rotated to the toner container replacement position 3 ₃ , 4 ₃ in FIGS. 1 and 8 to remove the toner container 3 so that a new toner container 3 can be mounted. By doing so, it is possible to prevent a problem that charging failure occurs due to mixing of new toner and deteriorated toner whose adhesion state of the external additive has changed to the toner, resulting in deterioration of image quality.

  In the above description, the mechanism of FIGS. 4 and 7 is shown as an example of the opening / closing mechanism of the shutters 31 and 46. However, the mechanism is not limited to such a mechanism, and any mechanism can be used as long as the shutters 31 and 46 can be opened and closed. Of course, a mechanism may be used.

  As described above, according to the present invention, the developer container is fixed to the rotary rack and the toner container is detachably supported so that the toner container and the developer are in contact with each other. An opening for moving toner between the shutters, and each of the openings has a means that is normally biased in the closing direction so as to be slidable in the opening and closing direction, and the rotary rack By providing a shutter that opens and closes in conjunction with the rotation of the toner, the opening and closing timing of the shutter is adjusted so that the new toner for replenishment and the toner in the developing device do not mix even when the rotary rack rotates. By setting the time when the toner can be replenished and when the deteriorated toner can be discharged into the toner container when the toner container is replaced, new toner and toner in the developing device As a result, the toner can be discharged when the toner container is replaced, and the mechanical mechanism is simply provided with an opening and a shutter. It is possible to provide a developing device in a rotary type image forming apparatus that does not require a means for detecting the toner amount of the developing member and the conveying member in the axial direction and the amount of toner in the axial direction, and that can be configured in a small size. .

  The center of the opening in the toner container and the developing unit is at a position that is at least the same height or lower than the axis of the supply roller at a position where the developing roller in the developing unit faces the image carrier. For example, when the opening position of the shutter for supplying toner from the toner container to the developing device is set to a position rotated from the position where the developing roller and the image carrier face each other to the lower side of the image carrier, supply Since the toner reservoir space between the roller and the opening does not become so large, there is no excessive supply or insufficient supply of toner from the toner container, and an appropriate amount of toner is always held in the developing device. Become.

  Further, a rotary rack is provided by means for forcibly opening the shutter at a toner supply angle position where the toner moves from the toner container to the developing device and a toner discharge angle position where the toner moves from the developing device to the toner container. Rotation of the toner does not cause oversupply or supply shortage, new toner for replenishment and toner in the developer unit are not mixed, and new toner can be supplied to the developer only when necessary, and deteriorated toner can be supplied to the toner. It is possible to provide a developing device in a rotary type image forming apparatus that can be discharged at the time of container replacement.

  The means for forcibly opening the shutter at the toner supply angle position is a convex portion provided on the image forming apparatus main body side in a circumferential direction from the angle position at which the shutter is opened to the angle position at which the shutter is closed. The means for forcibly opening the shutter in the toner container and the developing device at the discharge angle position is a stopper provided at the toner discharge angle position on the image forming apparatus main body side and protruding when the toner is discharged, and the shutter Has a mechanism that slides the shutter in the opening direction against the urging means by abutting against the convex portion or stopper at its end, so that the non-developing angle position and the toner container can be replaced with a very simple configuration. Easily and reliably open and close the shutter at the angular position to replenish new toner and discharge deteriorated toner It can be.

  According to the present invention, in a rotary type developing apparatus configured so that the toner container can be replaced, new toner is supplied to the developing device only when necessary without the new and old toners being mixed by the rotation of the rotary rack, and the toner is deteriorated. It is possible to provide a developing device that can discharge toner when the toner container is replaced, and can always obtain a high-quality image.

FIG. 2 is a diagram illustrating a schematic configuration of a developing device in the image forming apparatus of the present invention. FIG. 4 is a diagram illustrating a configuration of a toner container and a developing device of a developing device in the image forming apparatus of the present invention. FIG. 6 is a diagram for explaining a shutter opening / closing mechanism between the toner container and the developing device when toner is supplied from the toner container to the developing device. FIG. 6 is a diagram for explaining a shutter opening / closing mechanism between the toner container and the developing device when toner is supplied from the toner container to the developing device. FIG. 6 is a diagram for explaining shutter opening / closing timing and a toner supply operation from a toner container to a developing device. FIG. 6 is a diagram for explaining a method of discharging deteriorated toner in a developing device. FIG. 6 is an explanatory diagram of a shutter opening / closing mechanism when discharging deteriorated toner. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus having a developing device of the present invention.

Explanation of symbols

3 toner container 4 developing unit 30 opening 31 toner container side shutter 40 developing roller 41 supply roller 42 regulating blade 43 pressing member 44 seal member 45 opening 46 developing unit side shutters 50A, 50B, 50C, 50D toner container side toners 51A, 51B, 51C, 51D Developer side toner

Claims (5)

A cylindrical rotary rack having an image carrier that carries a latent image, a developing roller that develops the latent image on the image carrier, and a supply roller that carries toner to the developing roller, and is configured to be rotatable. A plurality of developing units that are fixedly moved by the rotation of the rotary type rack to sequentially move the developing roller to a position facing the image carrier, and the rotary type rack or the developing unit adjacent to the developing units; In a developing device in a rotary type image forming apparatus comprising a toner container detachably supported,
The toner container and the developing unit are opened and closed with an opening for moving the toner between the toner container and the developing unit at a position where the toner container and the developing unit are in contact with each other, and a means that is normally urged in the closing direction. A developing device in an image forming apparatus, comprising a shutter configured to be slidable in a direction and opened and closed in conjunction with rotation of the rotary rack.   The center of the opening in the toner container and the developing unit is at a position at least equal to or lower than the axis of the supply roller at a position where the developing roller in the developing unit faces the image carrier. The developing device in the image forming apparatus according to claim 1.   The shutter is forcibly opened at a toner supply angular position where the toner moves from the toner container to the developing device and a toner discharge angular position where the toner moves from the developing device to the toner container. 1. A developing device in the image forming apparatus described in 1.   The means for forcibly opening the shutter at the toner supply angle position includes a convex portion provided on the image forming apparatus main body side in a circumferential direction from an angle position at which the shutter is opened to an angle position at which the shutter is closed, and an end of the shutter. 4. The developing device in an image forming apparatus according to claim 3, wherein the developing device is a mechanism that is provided in a portion and slides the shutter in an opening direction against the urging unit by contacting the convex portion. 5.   Means for forcibly opening the shutter in the toner container and the developing device at the toner discharge angle position is provided at a toner discharge angle position on the image forming apparatus main body side, and is configured to protrude when the toner is discharged, and the shutter 4. The developing device in the image forming apparatus according to claim 3, wherein the developing device is a mechanism that is provided at an end of the image forming unit and slides the shutter in an opening direction against the urging unit by contacting the stopper.

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