JP4038297B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.In placeSpecifically, the present invention relates to replenishment of the two-component developer composed of toner and carrier to the developing device or recovery to the outside of the developing device.
[0002]
[Prior art]
Conventionally, various image forming apparatuses using a two-component developer obtained by mixing a toner and a carrier have been proposed. When the two-component developer is repeatedly used, the carrier component in the developer is gradually deteriorated, and the developing ability is lowered. For this reason, the developer inside the developing device including the deteriorated carrier is replaced.
As a method for replacing the developer, specifically, a method in which a service person visits the user every predetermined cycle to collect the old developer and supply a new developer is employed.
In addition, there is a method in which the developer is replaced by the user himself / herself. For example, a cylindrical container is used as the developer container of the developing device, and when the developer in the container deteriorates, a fixed amount of old developer is recovered from the container, and a fixed amount is stored in the same cylindrical container. The new developer is replenished.
[0003]
[Problems to be solved by the invention]
However, when the service person collects and replenishes the developer, the developer unit with at least one developer or a part of the developer unit is removed from the apparatus main body, so the developer may spill out. There was a risk of contaminating the surroundings (for example, see Japanese Patent Publication No. 3-22627). In addition, it may take time for the serviceman to change the developer, and it may be troublesome to call the serviceman frequently.
On the other hand, in the method in which the user replaces himself / herself, a certain amount of old developer can be recovered, but since the new developer is replenished without being completely recovered, the old developer remains.
[0004]
Note that the applicant of the present invention has previously developed a developing unit that contains a two-component developer obtained by mixing toner and a carrier, an agent stirring unit for stirring the developer contained in the developing unit, and the developing unit. A toner replenishing unit for replenishing toner in a toner bottle storing toner toward the agent agitating unit according to the amount of toner consumed in the unit, and a toner replenishing port communicating with the toner replenishing unit. In a developing device having a bottle holding portion for detachably holding the toner bottle in correspondence with the toner discharge port of the toner bottle, the outer shape of the developer bottle in which the developer is stored is The developer bottle is formed in the same or substantially the same shape as the outer shape, and the developer supply port connected to the toner supply port or the toner supply unit is associated with the agent discharge port of the developer bottle. Retention By proposes a developing device which is characterized in that the replenishment of the developer into the developing section (see JP-A-8-123170).
According to this developing device, it is possible to automatically replenish the developer by using the same drive means as the toner replenishment drive means, but it is not possible to collect the deteriorated developer inside the developing device outside the device. This was not considered, and the developer was not surely replaced.
[0005]
  The present invention has been made in view of the above problems, and the object of the present invention is to allow the user to surely replace the developer himself without bothering the serviceman.Image formationIs to provide a device.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention includes a developing unit that contains a two-component developer composed of toner and a carrier, and replenishes toner into the developing unit along a predetermined toner replenishment path. A plurality of toner replenishing means around the rotation axis, and the developer used by the rotation of the rotation shaft is moved to a development position opposite to the image carrier of the image forming apparatus and formed on the image carrier. In an image forming apparatus equipped with a two-component developing device that develops a latent image that has been developed, the rotating shaft is selectively rotated in the forward direction that is the rotational direction during the developing operation and in the opposite direction.RollingA rotatable rotating shaft drive device, an opening part of the toner replenishment path, screw members disposed on the upstream side and the downstream side of the replenishment path across the opening, and these screw members A screw drive device that rotates the screw and a shutter that opens and closes the opening, and the screw member rotates in the reverse direction by the rotary shaft drive device while the drive by the screw drive device is stopped. By disposing, the toner is arranged so as to convey toner in the direction opposite to that when driving by the screw driving device, and the opening is formed in a part of the axial direction of the screw member. One end swings due to its own weight to open and close the opening, and at least the developing devicepositionWhen the toner is being replenished by the toner replenishing means for the developing device at the developing position, the screw is driven to rotate by the screw drive device.ImagerWhen recovering developer fromKiIn the state where the screw driving device is stopped, the rotary shaft driving device rotates the rotating shaft in the reverse direction to reverse the entire two-component developing device a plurality of times, and the developer in the developing device is supplied to the toner replenishment path. Is collected outside the developing device through the same path in the reverse direction.
[0007]
  Claim 1Image formationIn the device, when the developer in the developer has deteriorated and must be replaced,Using the reverse rotation of the developing device,The developer can be collected by passing it in the opposite direction of the toner replenishment path, and can be collected with the developer unit attachedThe
[0008]
  Claim 2Image formationThe apparatus of claim 1Image formationIn the apparatus, a toner container in which toner is accommodated is configured to be detachable, and the toner replenishing means is configured to replenish the toner in the toner container in the developing device with the toner container mounted. Shi,UpThe developer collecting place to be collected by the developer collecting means is the toner container.
[0009]
  Claim 2Image formationIn the apparatus, the emptied toner container is reused as a developer collection container. This empty toner container may be attached to the apparatus for toner supply, and used as a collection container as it is without removing the empty toner container after toner supply. In addition, an empty toner container may be removed from the apparatus and mounted again when the developer is collected.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
A first embodiment in which the present invention is applied to a color electrophotographic printer (hereinafter referred to as a printer), which is an image forming apparatus, will be described below.
FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment. The surface of the photosensitive drum 10 as the image carrier is uniformly charged by the charging charger 2 as the charging means while being rotated in the direction of arrow A, and then the laser light emitted from the laser optical device 22 is mirrored. By being guided in a predetermined direction by 23, scanning exposure is performed based on image information, and an electrostatic latent image is formed on the surface. In the above process, the surface of the photosensitive drum 10 is negatively charged by the charging charger 2 (−V_D) When laser light is emitted from the laser optical device 22, the photoreceptor surface potential is -V._LIt becomes.
The image information to be exposed is monochromatic image information obtained by decomposing a desired full-color image into color information of yellow, magenta, cyan, and black. The electrostatic latent image formed on the photosensitive drum 10 is developed with yellow, magenta, cyan, and black toners as predetermined developers by a rotary developing device (hereinafter referred to as a revolver developing device) 4. Thus, each color image is formed on the photosensitive drum 10.
[0025]
Each color image formed on the photoconductive drum 10 is stretched around a bias roller 51 and a plurality of belt rollers 52 and can rotate, and rotates in the direction of arrow B in the figure in synchronization with the photoconductive drum 10. As a result, yellow, magenta, cyan, and black single colors are sequentially superimposed and transferred onto the intermediate transfer belt 50. The transfer of each color image onto the intermediate transfer belt 50 is performed by applying a predetermined bias voltage to the transfer bias roller 51 in a contact state between the photosensitive drum 10 and the intermediate transfer belt 50. The yellow, magenta, cyan, and black images superimposed and transferred on the intermediate transfer belt 50 are fed from the automatic paper feeding cassette 24 for double-sided copying or the manual paper feeding tray 24a to the paper feeding rollers 26 or 26a and the resist. The secondary transfer charger 11 performs batch transfer onto the transfer paper 10a conveyed to the transfer section via the roller 28. After the transfer, the transfer paper 10a is fixed with a toner image by the fixing device 12, and is discharged out of the apparatus as a full color print.
[0026]
Note that some untransferred residual toner on the photoconductor drum 10 after being transferred onto the intermediate transfer belt 50 is cleaned by the photoconductor cleaning device 13 in preparation for reuse of the photoconductor drum 10. The toner collected by the photoconductor cleaning device 13 is stored in a waste toner tank 90 via a collection pipe 17.
Further, the toner on the intermediate transfer belt 50 that has not been transferred onto the transfer paper 10a is removed from the intermediate transfer belt 50 by the intermediate transfer belt cleaning device 60 provided adjacent thereto.
[0027]
FIG. 2 is a schematic configuration diagram of the revolver developing device 4. The revolver developing device 4 includes four developing devices 40, 40Y of substantially the same type that are rotated in the direction of arrow C about a rotation shaft 4a in a casing (not shown) having an opening facing the photosensitive drum 10. 40M and 40C, and four toner replenishing devices 45, 45Y, 45M, and 45C for replenishing the four developing devices with replenishing toner, respectively. In the illustrated revolver developing device 4, a black developing device 40 containing black toner and a carrier faces a developing position facing the photosensitive drum 10, and from this black developing device 40 in the counterclockwise order in the figure. A yellow developing device 40Y containing yellow toner and a carrier, a magenta developing device 40M containing magenta toner and a carrier, and a cyan developing device 40C containing cyan toner and a carrier are arranged.
[0028]
The four developing devices 40, 40Y, 40M, and 40C of the revolver developing device are arranged at positions displaced by 90 degrees from each other, and the revolver developing device 4 is predetermined in the direction of arrow C by a stepping motor (not shown). The developing sleeves 41, 41C, 41M, and 41Y of the developing units are rotated by 90 degrees around the drive shaft 40a in accordance with the image forming process, so that the black developing unit 40, the cyan developing unit 40C, the magenta developing unit 40M, The yellow developing device 40Y is moved to the developing position facing the photoconductor drum 10 in this order, and the electrostatic latent image on the photoconductor drum 10 is visualized.
[0029]
The intermediate transfer belt cleaning device 60 is provided so as to cover the cleaning blade 61, a contact / separation arm 62 that supports the cleaning blade 61 so as to be able to contact and separate from the intermediate transfer belt 50, and the cleaning blade 61. And a recovery container 63 as a developer recovery part that is open to the intermediate transfer belt 50 side.
In the cleaning device for the intermediate transfer belt having the above-described configuration, the tip of the cleaning blade 61 can be brought into and out of contact with the surface of the intermediate transfer belt 50 through the contact / separation arm. Then, an image of the first color is transferred from the photosensitive drum 10 onto the intermediate transfer belt 50, and further, an image of a plurality of colors is transferred to form a superimposed image, and the superimposed image is transferred to the transfer paper at once. In the meantime, the cleaning blade is separated from the intermediate transfer belt 50, and after the batch transfer of the superimposed image onto the transfer paper is completed, the cleaning blade comes into contact with the intermediate transfer belt 50 and is not transferred to the transfer paper. The toner remaining on the surface is scraped off.
[0030]
The waste toner scraped off by the cleaning blade 61 falls to the bottom of the collection container 63 along the inner wall of the collection container 63 due to gravity. A second recovery pipe 92 connected to the waste toner tank 90 is connected to the bottom of the recovery container 63, and the waste toner in the recovery container 63 is accommodated in the waste toner tank 90 through the recovery pipe. The waste toner tank 90 is also connected to the photoconductor cleaning device 13 so that waste toner on the surface of the photoconductor drum 10 is also stored in the same waste toner tank 90.
[0031]
Here, since the internal structures of the four developing devices 40, 40Y, 40M, and 40C are the same, the internal structure will be described below taking the black developing device 40 at the developing position as an example, and the other developing devices will be described. Regarding the internal structure, as the reference numerals of the members corresponding to the respective black developing units, the same numbers as those in the black developing units are attached with subscripts of Y, M, and C to distinguish the yellow, magenta, and cyan developing units. The reference numerals are shown in the figure, and the description thereof is omitted.
[0032]
The developing device 40 includes a developing sleeve 41 as a developer carrying member and first and second agitators for agitating a two-component developer (hereinafter referred to as a developer) composed of black toner and a carrier housed in the casing portion. Screws 42 and 43 are provided.
Then, the black toner and the carrier are stirred in the black developing device 40, and the black toner is negatively charged and the carrier is positively charged. During development, the developing sleeve 41 has a negative bias (−V_B, V_B<V_D), While the photoreceptor potential -V_LIs V_L<V_BTherefore, the toner carried on the surface of the developing sleeve 41 moves to the image portion on the surface of the photoreceptor, and a toner image is formed on the surface of the photoreceptor.
[0033]
FIG. 3 is a partially enlarged view of the developing unit of the revolver developing device 4 at the developing position. During development, as shown in FIG. 3, the magnetic pole arrangement of the developing sleeve 41 facing the photosensitive drum 10 has a portion other than the region C where the magnetic force does not reach on the side facing the photosensitive drum 10. It is arranged like this. As a result, the developer carried on the developing sleeve 41 and remaining on the surface of the developing sleeve 41 without being used for development in the developing region falls into the developing unit due to its own weight when it reaches the region C by the rotation of the developing sleeve 41. . Then, after passing through the region C, new developer is adsorbed on the surface of the developing sleeve 41.
[0034]
FIG. 4 is a plan view of the black developing device. A flange 95 is press-fitted into a hole at one end in the longitudinal direction of the developing sleeve 41, and a shaft portion 95 a of the flange 95 is attached to the developing device housing via a bearing 96. Gear trains 81, 82, and 83 that transmit driving force to the developing sleeve 41 are attached to the outer end portion of the shaft portion 95 a. The developing sleeve 41 is driven by a motor 80 installed in the printer main body. When the motor is turned on, rotation is sequentially transmitted to the gear trains 81, 82, 83, and development is performed from the gear 83 through the flange of the developing sleeve 41. The sleeve 41 rotates.
[0035]
Here, of the developer in the developing device 40, the toner is consumed for each development. A toner replenishing device 45 is provided so that toner can be replenished when a decrease in toner concentration of the developer is detected by a toner concentration sensor (not shown).
In the printer of this embodiment, the developer is replenished in the developing device after the installation of the device for the purpose of preventing the leakage of the developer due to the transportation of the device, or a new development is performed after the developer is collected. A developer replenishing device for replenishing the developer is also provided.
Since these toner and developer supply devices have substantially the same configuration, only the toner supply device 45 will be described, and description of the developer supply device will be omitted.
[0036]
FIG. 5 is a perspective view of a toner bottle 46 as a toner container used in the toner replenishing device 45, FIG. 6 is a perspective view of the toner bottle 46 held by the bottle holding portion 145, and FIG. It is sectional drawing of the replenishment apparatus at the time of replenishment.
The toner replenishing device 45 includes a bottle holder 145 that holds the toner bottle 46, a motor 120 and a cup for rotating the bottle 46 in the circumferential direction while the toner bottle 46 is held by the bottle holder 145. A ring 121 is provided. As a result, the toner is replenished from the toner bottle 46 into the developing device, the toner density of the developer is maintained at a predetermined density, and as a result, the image density on the transfer paper is kept constant.
[0037]
In FIG. 5, the toner bottle 46 has a spiral transfer rib 47 formed on the inner peripheral surface of the bottle. Further, a toner discharge port 48 is provided in the vicinity of the end portion in the longitudinal direction of the bottle. As a result, when the toner bottle 46 rotates in the circumferential direction, the toner inside is sequentially conveyed to the toner discharge port 48 side along the transfer rib 47, and falls to the outside from the discharge port 48 by its own weight.
In FIG. 6, the peripheral surface of the toner bottle 46 displays whether the toner contained therein is black BL, cyan C, magenta M, or yellow Y. The color detection bosses 49 that are different for each color are formed on the outer periphery of the bottle as discriminating means. The color detection boss 49 is a detected portion that is detected by a sensor 110 serving as a detection means installed on the inner wall of the bottle holding portion 145, and can detect which color of the toner bottle 46 is set in the bottle holding portion 145. It is like that. Further, the toner bottle 46 and the developer bottle 146 display which of the toner and the developer is stored, which can be seen by the user. A boss 53 different from that of the developer bottle 146 is formed on the outer periphery of the bottle. As shown in FIG. 7, the boss 53 is detected by a sensor 111 serving as a detecting means installed on the inner wall of the bottle holding portion 145, so that it can be detected whether the toner bottle 46 or the developer bottle 146 is set. . Here, the developer bottle 146 of the present embodiment is used with only the carrier. However, the developer bottle 146 may be a mixture of toner and carrier in a predetermined ratio.
[0038]
In the above configuration, when the development is repeated and the toner is consumed and the toner density in the developing device 40 decreases, the user sets the toner bottle 46 of the corresponding color in the bottle holding unit 145. When the motor 120 is driven, the toner bottle 46 rotates in the circumferential direction via the coupling 121, and the toner in the toner bottle 46 is sequentially sent to the vicinity of the toner discharge port 48 and positioned downward from the toner discharge port 48. Then, the toner drops from the developing opening 65 into the developing device through the supply screw 47 to be supplied. Thereafter, the first and second agitating screws 42 and 43 are agitated and mixed with the developer containing the carrier, and are fed to the developing sleeve 41 as a two-component developer that is triboelectrically charged oppositely to each other. A path through which the toner passes from the toner bottle 46 to the developing device is referred to as a toner supply path.
[0039]
The two-component developer in each of the developing devices 40, 40Y, 40M, and 40C of the revolver developing device 4 needs to be periodically replaced because the carrier deteriorates particularly when used for a long time. For this reason, when a predetermined developer replacement time has elapsed, the developer is recovered from the developing device 40. The developer recovery method is a characteristic part of this embodiment, and will be described in detail later. After the developer is completely collected, when the user sets the developer bottle 146 of the color corresponding to the bottle holding unit 145, the developer bottle 146 is rotated in the circumferential direction via the coupling 121 by driving the motor 120. Then, the internal developer is sequentially conveyed to the discharge port 148 side along the transfer rib 147 formed on the inner wall of the bottle, and is dropped from the discharge port 148 into the developing unit positioned below by its own weight. Here, a path through which the developer passes through the discharge port 148 of the developer bottle 146 until the developer is replenished into the developing device (hereinafter referred to as a developer replenishment path) is that the toner is in the toner bottle at the time of toner replenishment. The toner passes through the same replenishment path as the toner replenishment path that passes from the 46 discharge ports 48 until the developer 40 is replenished.
Thereafter, when the toner is replenished, the developer is agitated and mixed with the toner by the first and second agitating screws 42 and 43, and is fed to the developing sleeve as a two-component developer that is frictionally charged with opposite magnetism. .
Next, a configuration for replacing the developer according to the characteristic part of the present embodiment will be described.
[0040]
Here, since all the deteriorated developers in the four developing units provided in the revolver developing device can be replaced in the same manner, the replacement of the deteriorated developer in the black developing unit 40 will be described as an example. In the printer of the first embodiment, the deteriorated developer can be recovered by passing it through the same path as the toner supply path in the direction opposite to the toner supply direction, that is, in the direction from the developer side toward the toner bottle 46. It has become.
FIG. 8 is an explanatory diagram of a developing device used in the first embodiment. FIG. 9 is a partially enlarged view of the shutter 70 provided in the developing device of the present embodiment. FIG. 10 is a cross-sectional view of the revolver developing device 4 provided with the shutter 70.
In FIG. 8, a shutter 70 that opens and closes depending on the position of the developing device by the rotation of the revolver developing device 4 is provided in the developing opening 65 of the toner replenishment path. One end of the shutter 70 is supported by the developing device housing so as to be swingable, and is opened and closed by its own weight.
When the toner is replenished, the developing opening 65 is opened so that the toner can fall from the replenishment screw 47 toward the second transport screw 43 as shown in FIG. Further, when the developing device opening is positioned in the gravity direction of the free end of the shutter 70 by the rotation of the revolver developing device 4, the shutter 70 is closed as shown on the right side of FIG.
[0041]
In FIG. 10, when the developer in the developing device is collected, the revolver developing device 4 is rotated in the direction opposite to that during development (in the direction of arrow D in the figure). Here, the rotation direction of the revolver may be switched by switching the rotation direction of a revolver driving motor (not shown) that applies a rotation driving force to the revolver developing device 4 in the opposite direction to the rotation direction during development.
When the revolver rotates, the shutter 70 changes from an open state to a closed state when passing between the position of the cyan developer unit and the position of the magenta developer unit in the drawing. Also, when passing between the position of the yellow developing device and the position of the black developing device in the drawing, the closed state is opened. Further, during the developer collecting operation, the toner bottle, the replenishing screw 47, the first and second stirring screws 42 and 43 are stopped, and the revolver is continuously rotated at a high speed a plurality of times. Do. Accordingly, the developer in the developing device gradually moves in the direction opposite to that during toner replenishment along the spiral screw blades of the first and second stirring screws 42 and 43 by the rotation of the revolver, and the developing opening 65 It is transported to the vicinity. Then, when passing through the position of the lowermost cyan developing device in the drawing, the developer is scooped up to the replenishing screw 47 side from the developing opening so that the developer is scooped up to the opened shutter 70, and then the revolver developing device 4 rotates. The toner is transported along the screw blades of the replenishing screw 47 to the toner discharge port 48 of the toner bottle 46 and is collected from the toner discharge port 48 into the toner bottle. In this way, the revolver developing device 4 is repeatedly rotated in the direction of arrow D for a certain period of time so that the recovery is gradually promoted.
If the rotation time of the revolver developing device 4 is set in advance as a total developer recovery mode so that all the developer in the developing device can be recovered in advance, and empty bottles are attached to all the bottle holders, Developer can be recovered from all the developing devices. In addition, a sensor for detecting the developer amount in the developing device may be provided, and the rotation may be stopped when the sensor detects that the developing device is empty.
[0042]
According to the above method, the developer can be recovered without removing the revolver developing device 4, and therefore the developer can be easily recovered by the user himself. Further, for the developer recovery, the developer can be recovered using only the rotation of the revolver developing device 4 and without driving other members. Further, since the developer can be stored in the bottle and the bottle can be removed and recovered, there is no risk of spilling the developer and contaminating the surroundings during recovery. Further, since the empty toner bottle is used as the collected developer container, it can contribute to cost reduction. Further, it is not necessary to provide a new driving member for collecting the developer.
[0043]
Further, the printer of this embodiment is provided with an all developer replenishment mode, so that the developer replenishment to the four developing devices can be completed in one operation. Hereinafter, the operation of the printer when the all developer supply mode is executed will be described.
After all the developing devices in the developing device have been emptied for the replacement of the developer, a developer bottle containing a new supply developer is attached to each bottle holder, and the all developer supply mode is executed. In this mode, the revolver developing device 4 rotates slowly in the direction of arrow C in FIG. 2, which is the same as during development, and one of the developing devices stops at the developer supply position where the developer bottle discharge port 148 is located at the bottom of the bottle. Then, the developer is replenished as described above. When the supply of the developer to one developer is completed, the next developer is transported to the developer supply position by the rotation of the revolver, and the developer is sequentially supplied to the developer. At this time, since the shutter 70 is closed while the replenishing screw 47 is below the developing opening 65, the developer does not flow backward to the developer bottle.
When the supply of the developer to the four developing devices is completed in this way, the replacement of the developer is completed.
[0044]
According to the printer of this embodiment, the developer supply to all the developers can be completed at once by executing the all developer supply mode, and the developer supply to each developer can be independently performed. This saves labor and saves replenishment time compared to giving instructions. Further, since the toner supply path and the developer supply path are the same, it is not necessary to newly provide a developer supply path, and the apparatus can be downsized.
Further, after executing the all developer recovery mode, if the recovery bottle is removed from the bottle holding unit 145, the developer bottle containing the replenishment developer is held, and the all developer supply mode is executed, all The developer in the developing device can be easily replaced.
[0045]
(referenceformstate)
  Next, the printer that can automatically collect the developerReference formWill be described. BookreferenceformStateSince the printer in this embodiment is the same as that of the first embodiment except for the configuration of the developer recovery device from the developing device, the description of the common parts is omitted.
  FIG.referenceformStateFIG. 12 is an explanatory diagram of such a printer.referenceformStateFIG. 3 is a partially enlarged view of a developer recovery device.
  In FIG. 11, the printer includes a developer recovery mode for recovering the developer in the developing device, and a photosensitive drum cleaning device 71 for removing the developer attached to the photosensitive drum 10 when the developer recovery mode is executed. And have.
  The photoconductor cleaning device 71 is for forcibly cleaning the developer attached to the photoconductor drum 10. The first recovery roller 71 provided at a position facing the photoconductor drum 10, below the recovery roller. A second collection roller 72 located at a position below, a collection screw 73 provided below the second collection roller 72 and spaced from the second collection roller 72, and the first and second collection rollers 71, 72 and the collection screw 73. It is comprised from the casing 75 which only the 1st collection | recovery roller 71 is exposed from the upper opening.
  The first recovery roller 71 is opposed to the surface of the photosensitive drum between the position facing the developing roller 41 and the position facing the intermediate transfer belt 50 in the rotational direction of the photosensitive drum 10, and is opposed to the photosensitive drum 10. It is configured to be able to contact and separate. Note that a neutralization device 76 is also provided on the upstream side of the first recovery roller facing position in the rotation direction of the photosensitive drum. The first recovery roller 71 is composed of a sleeve and a magnet having an upper portion with an N pole and an S portion with an N pole. Further, the second collection roller 72 is composed of a sleeve and a magnet of the same polarity arrangement in which the upper part is an N pole and the upper part is two S poles.
  The lower portion of the casing 75 is immersed in the recovery container of the intermediate transfer belt cleaning device 60 from above, and the developer is transported into the recovery container 63 by the recovery screw 73.
[0046]
In the above configuration, the flow of developer recovery when the developer recovery mode is executed will be described. When the developer recovery mode is entered, the developing unit containing the developer to be recovered is positioned at the development position and the rotation of the revolver is stopped. Then, the developing sleeve 41 is set to approximately 0 V without applying a developing bias to the developing device stopped at the developing position, and a voltage of about −500 V is applied to the photosensitive drum 10 by the charging device. In this state, the first and second stirring screws 42 and 43 and the developing roller 41 of the developing device are driven to rotate, and the developer pumped up by the developing roller 41 is attached to the photosensitive drum 10. The surface of the photosensitive drum 10 having the developer attached thereto is neutralized at a portion facing the neutralization device, and the developer carrying force is weakened and conveyed to the portion facing the first recovery roller 71. Then, the developer on the photosensitive drum is transferred to the first collection roller 71 side by the magnetic force of the first collection roller 71, and is conveyed to the area facing the second collection roller 72 by the rotation of the first collection roller 71, 2 Adhering to the collecting roller 72 side by magnetic force. Further, it falls onto the recovery screw 73 due to the repulsive force of the magnetic force and gravity at the position of the same polarity arrangement below the second recovery roller 72, and is transported to the recovery container of the intermediate transfer belt cleaning device 60 by this recovery screw 73 and recovered. The waste toner tank 90 is collected through a pipe.
[0047]
In this way, in the developer recovery mode, the developer that has deteriorated in the developing device is attached to the photosensitive drum 10 to clean the photosensitive drum 10, so that the development can be performed without removing the revolver developing device 4 from the printer body. The agent can be recovered.
Further, since the developer recovered from the photosensitive drum 10 can be recovered in the recovery container of the intermediate transfer belt cleaning device 60, there is no need to provide a new developer recovery place, and the apparatus can be prevented from being enlarged. effective.
[0048]
  BookreferenceformStateIn the printer, a photosensitive drum cleaning device 71 is provided in the middle of conveying the developed image between the developing position and the intermediate transfer position on the photosensitive drum. For this reason, it is possible to remove only the carrier component such as ferrite that is unexpectedly attached on the formed image by the photosensitive drum cleaning device 71 during the conveyance of the image on the photosensitive drum 10 to the intermediate transfer belt 50. As a result, problems on the image such as white spots can be prevented.
[0049]
【The invention's effect】
  Claim 1Or 2ofImage formationAccording to the apparatus, the developer can be collected from the developing unit without removing the developing unit from the apparatus main body, so that the developer collecting operation is easy and the developer spills out of the developing unit and contaminates the surroundings. There is no. Further, if the developer in the developing device is collected until it becomes empty and then charged with a new developer, the developer can be completely replaced. Therefore, there is an excellent effect that the developer can be reliably replaced by the user himself without bothering the serviceman.
  In addition, since the developer can be replaced without removing the developing device, the time for replacing the developer can be reduced accordingly.Image formationThe operating rate of the apparatus can also be increased.
  In addition, there is no need to provide a new collection path for developer collection, compared to providing a new collection path.Image formationThere is also an excellent effect that the enlargement of the apparatus can be prevented.
[0050]
  In particular, in claim 2Image formationAccording to the apparatus, there is an excellent effect that the toner container can be reused as a developer collection container.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a printer according to an embodiment.
FIG. 2 is a schematic configuration diagram of a revolver developing device.
FIG. 3 is a partially enlarged view of a developing unit at a development position.
FIG. 4 is a plan view of a black developing device of a revolver developing device.
FIG. 5 is a perspective view of a toner bottle used as a toner replenishing device or a developer bottle as a developer container.
FIG. 6 is a perspective view illustrating a state where the toner bottle or the developer bottle is held by the bottle holding unit.
FIG. 7 is a cross-sectional view of a replenishing device.
FIG. 8 is an explanatory diagram of a developing device used in this embodiment.
FIG. 9 is a partially enlarged view of the developing shutter portion.
FIG. 10 is a cross-sectional view of a rotary developing device provided with a shutter.
FIG. 11referenceformStateAn explanatory view of such a printer.
FIG.referenceformStateThe elements on larger scale of a developer collection | recovery apparatus.
[Explanation of symbols]
  2 Charger charger
  4 Revolver development device
  10 Photosensitive drum
  13 Cleaning device for photoconductor
  17 Recovery pipe
  26 Paper feed roller
  28 Registration Roller
  40 Rotating type developing device
  40, 40Y, 40M, 40C Developer
  41, 41Y, 41M, 41C Development sleeve
  45, 45Y, 45M, 45C Toner supply device
  46 Toner Bottle
  47 Supply Screw
  48 Toner outlet
  60 Cleaning device for intermediate transfer belt
  63 Collection container
  70 Shutter
  90 Waste toner tank
  92 Second recovery pipe
  101 Collection port
  103 Recovery container
  145 Bottle holder
  146 Developer bottle

Claims (2)

A plurality of sets around a rotating shaft are provided around a rotating shaft, each of which includes a developing unit for storing a two-component developer composed of toner and a carrier, and a toner replenishing means for replenishing toner into the developing unit along a predetermined toner replenishing path. An image forming apparatus comprising a two-component developing device for developing a latent image formed on an image carrier by moving a developing device used by rotation of a rotation shaft to a developing position facing the image carrier of the image forming device. In
A positive direction with the rotation axis in the direction of rotation of the developing operation, and selectively rotating Utateka rotatably rotation axis driving device to the opposite direction opposite thereto,
An opening constituting a part of the toner supply path;
A screw member disposed on each of the upstream side and the downstream side of the replenishment path across the opening;
A screw driving device that rotationally drives these screw members;
A shutter for opening and closing the opening,
The screw member is rotated in the reverse direction by the rotary shaft drive device in a state in which the drive by the screw drive device is stopped, so that the screw member is driven in a direction opposite to that when the screw drive device is driven. It is arranged to convey the toner, and the opening is formed in a part of the screw member in the axial direction.
The shutter is attached so that one end side swings by its own weight to open and close the opening, and at least when the developing device is in the developing position , the opening is opened.
During the toner replenishment operation by the toner replenishing means for the developing device at the development position, the screw driving device rotates the screw,
It can for retrieving developer from the current image instrument, reversed a plurality of times across rotationally driving two-component developing device rotary axis in the opposite direction by the rotation axis driving device in a state of stopping the screw driving device, the developing device The image forming apparatus is characterized in that the developer inside is passed through the same path as the toner replenishing path in the reverse direction and collected outside the developing unit. The image forming apparatus according to claim 1.
A toner container that contains toner therein is configured to be detachable, and the toner replenishing means is configured to replenish the toner in the toner container into the developer in a state in which the toner container is mounted,
An image forming apparatus, wherein the developer collecting place to be collected by the developer collecting means is the toner container.

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