JP2011242539A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an air path by connecting gaps generated in a joint portion of each toner discharge unit through a conveyance path in a configuration in which toner discharged from a plurality of toner discharge units is joined to a main body recovery toner pipe. As a result, toner scattering occurs.
SOLUTION: A shutter that operates in conjunction with the setting of the toner discharge unit in the drum direction is provided at a joint portion on the main body side connected to the toner discharge unit, and the gap between the unit transfer pipe and the clearance is closed, thereby collecting the collected toner. Prevent backflow.
[Selection] FIG.

Description

  The present invention relates to an image forming apparatus having a plurality of toner discharge devices which are detachably provided in an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer and have a discharge port for discharging toner. More specifically, the present invention relates to an image forming apparatus having a conveyance path for merging and conveying toner discharged from a plurality of toner discharge apparatuses.

  In an image forming apparatus such as a copying machine or a printer using electrophotographic technology, an electrostatic latent image formed on an image carrier such as a photosensitive drum is developed as a toner image by a developing unit. Then, after the toner image is transferred to a sheet, the toner image is fixed on the sheet by a fixing unit to obtain an image. The toner remaining on the image carrier after the toner image is transferred to the paper is removed from the image carrier as recovered toner by the cleaning device. Then, the cleaning unit discharges the removed toner toward the collection container through the toner conveyance path provided on the main body side.

  In addition to the cleaning device described above, for example, a developing device can be considered as a toner discharging device that discharges waste toner. Such a developing device is called a trickle developing device, and is provided with a discharge port for discharging the deteriorated developer. The toner discharged from the discharge port is recovered into a recovery container through a recovery toner conveyance path.

  For example, when there are a plurality of toner discharge units such as a trickle developing device and a cleaning device as in Patent Documents 1 and 2, the toner discharged from each discharge unit is merged and transported on the same transport path, and finally the same Collect in the collection container. By doing so, the toner conveyance path can be simplified and an increase in the number of parts can be suppressed.

  On the other hand, Patent Document 3 discloses a configuration in which a developing unit can be moved between a pressurized state and a retracted state with respect to a drum unit (image forming unit). By doing so, the drum unit and the developing device can be made separate units and can be maintained separately, so that maintainability can be improved.

JP 2006-119289 A JP 2009-204678 A JP 2008-191233 A

  However, when Patent Document 3 is adopted in the configurations of Patent Documents 1 and 2, there are the following problems. That is, each toner discharge unit is inserted and attached to a collected toner conveyance path provided on the main body side. At this time, when each toner discharge unit is configured to be able to contact and separate from the image forming unit, the opening of the joint portion of the main body side toner transport pipe and the unit side toner transport pipe is moved toward and away from the drum. It is necessary to provide as much as possible. Therefore, a gap generated in the joint portion is formed.

  When there are a plurality of toner discharge units, a plurality of the gaps are formed, and an air passage through which air flows is formed through the toner transport pipe on the main body side. Then, under the influence of airflow in the image forming apparatus main body, air flows in the air path.

  Then, depending on the direction of the air flow, a portion where the gap between the joint portions of the plurality of toner discharge units becomes an intake portion and a portion that becomes an exhaust portion is formed. Thus, there has been a problem that the toner collected in the conveying path on the main body side is ejected from the exhaust portion, and the inside of the apparatus is soiled.

  The configuration of the image forming apparatus according to the present invention for solving the above-described problems includes an image carrier that carries an image, a first position that is located at the time of image formation, and a direction away from the image carrier from the first position. A plurality of units that are movably provided to the second position and that are provided with discharge ports for discharging toner, and are fixed to the apparatus main body and are connected to each of the plurality of units. A plurality of openings, and a conveyance path for merging and conveying the toner discharged from the plurality of units, wherein the discharge ports of the plurality of units are connected to the plurality of openings, respectively. In the state, the plurality of openings are formed corresponding to the movement regions of the plurality of units so that the plurality of units can move from the first position to the second position. Unit A plurality of shutter members, wherein the plurality of portions of the openings for blocking respectively when in the serial first position, characterized by having a characterized by having a.

In addition, an image forming apparatus according to the present invention for solving the above-described problems includes an image carrier that carries an image, a first position that is located at the time of image formation, and a distance from the image carrier from the first position. A plurality of image forming units each configured to form an image, each of which includes a unit provided with a discharge port for discharging the toner.
A plurality of openings provided to be fixed to the apparatus main body and connected to the units provided in each of the plurality of image forming units; and from the units provided in each of the plurality of image forming units. A transport path for merging and transporting the discharged toner, and the unit is movable from the first position to the second position in a state in which the discharge ports are connected to the openings. The opening is formed so as to correspond to the moving area of the unit, and a plurality of shutter members that respectively block a part of the opening when the unit is in the first position; It is characterized by having.

  According to the present invention, in an image forming apparatus that discharges toner from a plurality of toner discharge units on a common conveyance path, an air path is formed by connecting connection ports to the plurality of toner discharge units via the conveyance path. Can be suppressed.

Image forming apparatus sectional view showing a first embodiment Collected toner transport path diagram showing the first embodiment Schematic diagram of the image forming unit Schematic diagram showing the retracted state of the collected toner generation unit Schematic diagram showing the state where the collected toner generation unit is pulled out Detail of shutter on main unit (cleaning device side) Detail of main unit shutter (developer side) Unit side shutter details (shutter closed) Unit side shutter details (shutter open) Shutter operation explanation diagram 1 Shutter operation explanation diagram 2 Shutter operation explanation diagram 3 Shutter operation explanation diagram 4 Image forming apparatus sectional view showing a second embodiment Image forming unit and recovered toner path diagram of second embodiment Detailed view of developer shutter (shutter closed) (Example 2) Detailed view of developer shutter (shutter open) (Example 2) Detail of shutter on main unit side (Example 2) Shutter operation explanatory diagram 1 (Example 2) Shutter operation explanatory diagram 2 (Example 2) Shutter operation explanatory diagram 3 (Example 2) Shutter operation explanatory diagram 4 (Example 2)

[Example 1]
Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a schematic cross section of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus according to the present embodiment is a digital copying machine that has a printer function and a copying function, and forms an image based on image information transmitted from an external device such as a controller or the image reading unit 100.

  That is, the image forming apparatus includes an image reading unit 100, an image processing unit (not shown) that generates an image forming signal based on image information, and an image forming unit 101. In addition, the paper cassettes C1 and C2 and the paper feeding unit 102 that feeds the paper P from the paper cassettes C1 and C2, the transfer conveyance unit 103 that conveys the paper P to the transfer point A, the fixing device 104, and the paper after transfer A fixing conveyance unit 105 that conveys P to the fixing device 104 is provided. Then, a paper discharge processing unit 106 that switches the path of the paper P when discharging from the outside and double-sided / multiple and a double-side / multiple processing unit 107 that switches the path of the paper P and reverses the front and back of the paper P when double-sided or multiplexed. Have. Furthermore, a double-sided / multiple conveying unit 108 that conveys the paper P again to the transfer conveying unit 103 when double-sided or multiple images are formed is provided.

  The image forming unit 101 forms a toner image based on image information transmitted from an external device (not shown) such as a controller or the image reading unit 100. Specifically, based on the image formation signal generated by the image processing unit, the laser light L emitted from the laser exposure device 109 is imaged on the photosensitive drum 1 as an image carrier to form an electrostatic latent image. A toner image is formed by forming and developing with the developing device 2. A primary charger 3 and a cleaning device 4 are arranged around the photosensitive drum 1. Each operation of the image forming unit 101 is controlled by an image formation control unit (not shown).

  Further, at the transfer point A, the transfer roller 5 is disposed to face the photosensitive drum 1, and the toner is transferred onto the sheet P conveyed from the registration roller pair 11 of the transfer conveyance unit 103 in synchronization with the toner image on the photosensitive drum 1. The image is transferred. Then, the sheet P on which the toner image is transferred is conveyed to the fixing device 104 by the fixing conveyance unit 105. The residual toner remaining on the photosensitive drum 1 after the transfer of the toner image onto the paper P is removed from the photosensitive drum 1 by the cleaning device 4 and then discharged from the cleaning device 4 as recovered toner.

  The paper P on which the image has been fixed by passing through the fixing device 104 passes through the paper discharge processing unit 106 and is discharged out of the apparatus or sent to the double-side / multi-processing unit 107 according to the operation sequence. During double-sided or multiple printing, the paper P is route-changed by the first route switching device 12 of the paper discharge processing unit 106 and conveyed to the double-sided / multiple processing unit 107. The sheet P transported to the duplex / multiple processing unit 107 is further sent to the duplex / multiple transport unit 108 when multiplexed by the second path switching device 13 and to the reverse roller 14 when duplexed. Then, after the front and rear ends in the transport direction are reversed in the reverse direction, the paper is transported to the duplex / multiple transport unit 108. Then, the sheet P is sent again from the duplex / multiple conveyance unit 108 to the transfer conveyance unit 103, and the next image is transferred.

  Thus, the image forming apparatus according to the present embodiment uses a two-component developer composed of toner and magnetic carrier as the developer. Then, a trickle development system is employed in which the deteriorated developer that has become excessive as the developer is replenished from the developer replenishing device (not shown) is discharged from the developing device 2. Then, the deteriorated developer discharged from the developing device 2 and the residual toner discharged from the cleaning device 4 are both transported as recovered toner to a recovered toner container 31 provided at the rear of the apparatus.

  Here, the transport path (transport path) of the recovered toner transported from the developing device 2 as the toner discharge unit and the cleaning device 4 to the recovered toner container 31 will be described in detail. FIG. 2 is a schematic view of the collected toner conveyance path from the developing device 2 and the cleaning device 4 to the collected toner container 31.

  In the image forming apparatus according to the present exemplary embodiment, the collected toner conveyance path is arranged on the rear side of the apparatus similarly to the collected toner collecting container 31. As shown in FIG. 2, a deteriorated developer discharge path 21 connected to a deteriorated developer discharge port provided on the rear side of the developing device 2 and a residual toner discharge port provided on the rear side of the cleaning device 4. And a residual toner discharge path 22 connected to. The deteriorated developer discharge path 21 is connected to the first collected toner transport path 23. The deteriorated developer discharged from the deteriorated developer discharge port of the developing device 2 is discharged from the deteriorated developer discharge path 21 by free fall as indicated by an arrow B, and reaches the first recovered toner transport path 23. Similarly, the residual toner discharge path 22 is connected to the first collected toner transport path 23. The residual toner discharged from the residual toner discharge port of the cleaning device 4 falls freely as indicated by an arrow C. As a result, the toner is discharged from the residual toner discharge path 22 and reaches the first collected toner transport path 23.

  The deteriorated developer and residual toner that have reached the first collected toner conveyance path 23 are conveyed in the direction of arrow D by the first collected toner conveyance screw 24 provided in the first collected toner conveyance path 23, and Both merge at the junction F. The first collected toner conveyance path 23 includes a first collected toner discharge path 25 on the downstream side in the collected toner conveyance direction. As indicated by an arrow E, the deteriorated developer and the residual toner merged in the merge portion F are conveyed as a collected toner to the collected toner buffer 26 that can store the collected toner through the first collected toner discharge path 25.

  The collected toner buffer 26 is provided with a discharge port connected to a second collected toner conveyance path 29 having a second collected toner discharge path 30 for discharging the collected toner to the collected toner container 31. The collected toner in the collected toner buffer 26 is conveyed in the direction of arrow G along the second collected toner conveyance path 29 by the second collected toner conveying screw 28. The free fall from the second collected toner transport path 29 is transported to the collected toner collection container 31 through the second collected toner discharge path 30 as indicated by an arrow H. The collected toner buffer 26 is provided with a stirring member 27, and the stored collected toner is stirred by the stirring member 27.

  The developing device 2 and the cleaning device 4 can be detached as a single unit in consideration of maintainability. From the unit set state of FIG. 3, it is detachable once in the arrow direction (contact / separation direction) as shown in FIG. 4, and after retracted from the drum, it can be pulled out in the forward direction as shown in FIG. When the unit is inserted, the reverse operation is performed. In this way, by pulling out the unit after retracting from the drum, the drum can be removed without scratching.

[Shutter mechanism of recovery unit connecting part]
Next, details of the shutter on the main body side and the unit side shutter, which are the features of the present invention, will be described.

  Unit shutters of the developing device 2 as the first unit and the cleaning device 4 as the second unit are shown in FIGS. 8 shows the shutter closed state, and FIG. 9 shows the shutter open state. In the figure, unit recovery toner conveying screws 2a and 4a, unit shutters 2b and 4b, and shutter urging springs 2c and 4c are shown. The unit shutters 2b and 4b are urged by shutter urging springs 2c and 4c in the direction of the arrow in FIG. When the unit is set in the main body, the front end is pushed, the shutter is opened in the direction of the arrow in FIG. 9, and the collected toner conveyed by the unit collected toner conveying screws 2a and 4a falls from the opening. Thereafter, the collected toner passes through the deteriorated developer discharge path 21 and the residual toner discharge path 22 and is sent to the first recovered toner transport path 23.

  Next, the shutter on the main body side will be described with reference to FIGS.

  The deteriorated developer discharge path 21 and the residual toner discharge path 22 are each provided with a connection port (opening) for connecting the developing device 2 and the cleaning device 4. The opening corresponds to a moving area of the developing device 2 and the cleaning device 4 so that the developing device 2 and the cleaning device 4 can move in a state of being connected to the transport path. That is, the opening has a long hole shape along the moving direction of the developing device 2 and the cleaning device 4.

  The joints (openings) of the deteriorated developer discharge path 21 and the residual toner discharge path 22 are provided with main body shutters 21b and 22b, and are urged in the direction indicated by the arrows by the shutter urging springs 21c and 22c, respectively. Has been.

  The operation of the shutter unit when the unit is attached / detached will be described with reference to FIGS. As for the configuration of the shutter unit, the configuration on the developing device 2 side and the cleaning device 4 side are substantially similar in configuration because of the mirror image, and therefore the shutter configuration on the cleaning device 4 side will be described. The insertion / extraction direction of the cleaning device 4 and the contact / separation direction with respect to the drum have a substantially orthogonal relationship. When the cleaning device 4 is inserted into the image forming apparatus (FIG. 10), the unit side shutter 4b as the unit shutter member moves in the direction of the arrow in FIG. 11 by coming into contact with the taper portion Tp of the main body side shutter 22b. The main body side shutter 22b is urged by a spring so as to be movable in a direction to close the opening (connection port).

Then, the main body side shutter 22b moves in a direction (shutter opening direction) in which the opening expands against the urging force of the spring by the inserting operation of the unit. Since the unit shutter urging spring 4c is set stronger than the main unit shutter urging spring 22c, the unit side shutter 4b is opened first with almost no opening. Thereafter, the unit-side shutter 4 b is opened by abutting against the inner surface of the residual toner discharge path 22. (Fig. 12)
The unit-side shutter 4b abuts against the inner surface of the residual toner discharge path 22 in a state where all the discharge ports of the unit-side shutter 4b are inserted into the residual toner discharge path 22. As described above, the unit shutter is opened with all the unit discharge ports being inserted into the conveyance path on the main body side, so that the collected toner can be prevented from scattering into the image forming apparatus when the unit is attached or detached. Finally, the cleaning device 4 is set in the drum direction (mounted at the mounting position) with the cleaning device 4 connected to the conveyance path on the main body side, and at the same time, the main body shutter 22b is closed.

Here, the state where the cleaning device 4 and the conveyance path on the main body side are connected means that the discharge port of the cleaning device is in communication with the conveyance path. By doing so, it is possible to shield the gap of the connection port connecting the cleaning device 4 provided in the residual toner discharge path 22. (Fig. 13)
Since the developing device 2 has the same shutter configuration as described above, the recovered toner leaks back from the first recovered toner conveyance path 23 on the main body side through the deteriorated developer discharge path 21 and the residual toner discharge path 22. Never come.

  Further, the main body side shutter 22b has a force that urges the cleaning device 4 in the same direction as the direction in which the cleaning device 4 moves from the retracted position to the operating position with respect to the photosensitive drum. For this reason, there is no resistance to the unit set, and there is an effect of assisting a smooth set.

  As described above, good image printing can be performed without scattering due to the collected toner in the image forming apparatus.

  When the cleaning device 4 and the developing device 2 are not set in the main body, the main body side shutters 22b and 21b are slightly opened as shown in FIGS. 6, 7, and 10, but the unit is set. If not, there is no problem because the airflow of the image forming apparatus is stopped.

[Example 2]
The second embodiment is an example applied to a configuration having a plurality of image forming units. The reference numerals in this embodiment are different from those in the first embodiment.

  FIG. 14 is a schematic longitudinal sectional front view of an example of the image forming apparatus A to which the present embodiment is applied. This image forming apparatus A is a four-color tandem type, intermediate transfer type color digital printer (color image forming apparatus) using an electrophotographic process. The image forming apparatus A performs an image forming operation on a recording material (transfer material) in accordance with electrical image information input from an external host device C that is communicably connected to a control circuit unit (control means) B. A full-color image can be formed and output. The external host device C is a computer, an image reader, a counterpart facsimile machine, or the like.

  Reference numerals a to d denote first to fourth image forming units arranged in parallel (tandem) in the horizontal direction from the left side to the right side in the drawing in the main body of the image forming apparatus. The first image forming unit a is for forming a yellow (Y) color image, the second image forming unit b is for forming a magenta (M) color image, and the third image forming unit c is a cyan (C) color. For image formation, the fourth image forming portion d is for black (K) color image formation.

  Each of the image forming units includes a drum-type electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) 1001 (a to d) as an image carrier, and an image forming process unit that acts on the photosensitive drum. The image forming process means includes a charging roller 1002 (ad) as a charging means, a laser scanner 1003 (ad) as an image exposure means, a developing device 1004 (ad) as a developing means, and a primary transfer means. Primary transfer rollers 1005 (a to d). Also, a drum cleaner 1006 (ad) as an image carrier cleaning means. A toner cartridge 1007 (ad) for supplying toner to each developing device 1004 (ad) is provided. The developer 1004a and the toner cartridge 1007a of the first image forming unit a contain Y toner as a developer. The developer 1004b and the toner cartridge 1007b of the second image forming unit b contain M color toner as a developer. The developer 1004c and the toner cartridge 1007c of the third image forming unit c contain C-color toner as a developer. The developer 1004d and the toner cartridge 1007d of the fourth image forming unit d contain K color toner as a developer.

  An intermediate transfer unit 1008 is disposed below the first to fourth image forming units a to d. This unit 1008 has an endless intermediate transfer belt 1009 made of a dielectric and having flexibility as an intermediate transfer member. The belt 1009 includes a tension roller 1010, a driving roller 1011, a secondary transfer counter roller 1012, and a belt cleaner 1014 as a cleaning unit for the belt 1009. The lower surfaces of the photosensitive drums 1 of the first to fourth image forming units a to d are in contact with the upper surface of the ascending belt portion between the tension roller 1010 and the driving roller 1011 of the belt 1009. Each primary transfer roller 1005 is disposed on the inner side of the belt 9 and is pressed against the lower surface of the corresponding photosensitive drum with the ascending belt portion between the tension roller 1010 and the driving roller 1011 of the belt 1009 interposed therebetween. is doing. In each of the image forming portions a to d, a contact portion between the photosensitive drum 1001 and the belt 1009 is a primary transfer portion. Further, a secondary transfer roller 1013 as a secondary transfer unit is in pressure contact with the secondary transfer counter roller 1012 with the belt 1009 interposed therebetween. A contact portion between the secondary transfer roller 1013 and the belt 1009 is a secondary transfer portion.

  The operation for forming a full-color image is as follows. The control circuit unit B executes predetermined image formation sequence control based on the image formation start signal. In each of the image forming units a to d, the photosensitive drum 1001 (a to d) is rotationally driven in a counterclockwise direction indicated by an arrow at a predetermined control speed (process speed). The belt 1009 is also rotationally driven in a clockwise direction indicated by an arrow (forward direction with respect to the rotation of the photosensitive drum) at a speed corresponding to the speed of the photosensitive drum 1001. Each laser scanner 1003 (ad) is also driven. In synchronization with this drive, the charging rollers 1002 (a to d) uniformly apply the surface of the photosensitive drum 1 (a to d) to a predetermined polarity and potential at each of the image forming units a to d at a predetermined control timing. Is charged (charging process). Then, a Y color component image signal of a full color image is output from the control circuit unit B to the laser scanner 1003a of the first image forming unit a at a predetermined control timing. An M color component image signal of a full-color image is output from the control circuit unit B to the laser scanner 1003b of the second image forming unit b at a predetermined control timing. The C color component image signal of the full color image is output from the control circuit unit B to the laser scanner 1003c of the third image forming unit c at a predetermined control timing. A K color component image signal of a full color image is output from the control circuit unit B to the laser scanner 1003d of the fourth image forming unit d at a predetermined control timing. Each laser scanner 1003 (a to d) scans and exposes the surface of each photosensitive drum 1001 (a to d) with a laser beam modulated in accordance with an image signal of each color (exposure process). This exposure neutralizes the charge, and an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 1001 (a to d). The formed electrostatic latent image is developed as a toner image by the developing devices 1004 (a to d) (development process).

  By the electrophotographic image forming process operation as described above, a Y color toner image corresponding to the Y color component of the full color image is formed on the photosensitive drum 1001a of the first image forming unit a at a predetermined control timing. An M color toner image corresponding to the M color component of the full color image is formed on the photosensitive drum 1001b of the second image forming unit b at a predetermined control timing. A C toner image corresponding to the C color component of the full color image is formed on the photosensitive drum 1001c of the third image forming unit c at a predetermined control timing. A K-color toner image corresponding to the K-color component of the full-color image is formed on the photosensitive drum 1001d of the fourth image forming unit d at a predetermined control timing.

  As described above, the color toner images formed at the predetermined control timing on the photosensitive drums 1001 (a to d) of the image forming units a to d are rotationally driven to be rotated by the image forming units a to d. The primary transfer portion is sequentially superposed on the surface of the belt 1009 that sequentially moves, and is primarily transferred. That is, an unfixed toner image of four colors of Y color + M color + C color + K color is synthesized and formed on the belt 1009. The toner image moves to the secondary transfer portion by the subsequent rotation of the belt 1009. Further, the transfer residual toner on the photosensitive drum 1 that has not been transferred onto the belt 1009 in the primary transfer portions of the image forming portions a to d is collected by the drum cleaner 1006 (a to d).

  On the other hand, paper or the like is recorded at a predetermined control timing from any one of the first paper feed cassette unit 1015, the second paper feed cassette unit 1016, or the manual paper feed unit 1017 that is selected and specified in advance. The material P is separated and fed. The fed recording material P is conveyed by the conveying roller 1019 in the sheet path 1018 and is sent toward the registration roller 1020. Then, the recording material P is subjected to skew correction by forming a loop with the leading end abutting against the nip portion of the registration roller 1020 that has stopped rotating at that time. Thereafter, the recording material P is introduced into the secondary transfer section by the registration roller 1020 being rotated at a predetermined control timing in synchronization with the toner image on the belt 1009. As a result, the full-color toner image on the belt 1009 is secondarily transferred onto the surface of the recording material P. Further, the transfer residual toner on the belt 1009 that has not been transferred onto the recording material P in the secondary transfer portion is collected by the belt cleaner 1014.

  Then, the recording material P that has undergone the secondary transfer of the toner image is introduced into the fixing device 1021, and passes through the fixing nip portion between the fixing member and the pressure member, whereby the color mixture of each color toner image and the heat and pressure is performed. Receives fixing on the surface of the recording material.

  The recording material P that has exited the fixing device 1021 passes through the sheet path 1022 and passes through the first paper discharge unit 1025 or the second paper discharge unit 1026 selected and designated in advance, to the first paper discharge port 1023 or the second paper discharge. The paper is discharged from the paper mouth 1024.

  Double-sided image formation is also possible. When this image forming mode is selected, the recording material P on which an image has been formed is switched back and conveyed by the sheet path 1022 to one side which has exited the fixing device 1021 and is discharged and conveyed by the sheet path 1022. Enter the pass 1027. Then, the sheet is again reversed and sent to the registration roller 1020 by the sheet path 1018, and the secondary transfer portion receives the secondary transfer of the toner image on the other side, and is again introduced into the fixing device 1021. As a result, images are formed on both sides of the recording material P, and are discharged to the first paper discharge unit 1025 or the second paper discharge unit 1026 through the sheet path 1022.

  Next, the image forming unit and the transport path of the collected toner will be described with reference to FIG. In FIG. 15, only the magenta image forming unit b is shown for convenience. The other three image forming units a, c, and d have the same configuration although not shown.

  Similar to Example 1, the image forming apparatus according to the present embodiment uses a two-component developer composed of toner and a magnetic carrier as a developer. Then, a trickle development system is employed in which the deteriorated developer that has become excessive due to the developer supply from the developer supply device 1007 is discharged from the developing device 1004. The deteriorated developer discharged from the developing device 1004 and the residual toner discharged from the cleaning device 1006 are both transported as recovered toner to a recovered toner container (not shown) provided at the rear of the apparatus.

  In the image forming apparatus according to the present embodiment, as shown in FIG. 15, the collected toner conveyance path is a deteriorated developer discharge path 121 connected to a deteriorated developer discharge port provided on the rear side of the developing device 1004. Is provided. Further, a residual toner discharge path 122 connected to a residual toner discharge port provided on the rear side of the cleaning device 1006 is provided. The deteriorated developer discharge path 121 and the residual toner discharge path 122 are connected to the first collected toner transport path 123. The deteriorated developer discharged from the deteriorated developer discharge port of the developing device 2 and the residual toner discharged from the residual toner discharge port of the cleaning device 1006 are respectively discharged from the deteriorated developer discharge path 121 and the residual toner discharge path 122 by free fall. It merges in the main body collected toner conveyance path 123. Thereafter, the residual toner is conveyed in the direction of the arrow on the main body collected toner conveyance path, and is conveyed to the collected toner container.

  Here, the developing device 1004 (4b) can be detached as a single unit in consideration of maintainability, and after being retracted from the drum in the direction of the arrow X, the developing device 1004 (4b) is removed in the Y direction. On the other hand, the cleaning device 1006 (6b) performs maintenance by pulling it forward along with the drum as indicated by an arrow.

  Next, details of the shutter on the main body side and the unit side shutter, which are the features of the present invention, will be described.

  The unit shutter of the developing device 4 is shown in FIGS. 16 shows the shutter closed state, and FIG. 17 shows the shutter open state. In the figure, a unit recovery toner conveying screw 101, a unit shutter 102, and a shutter biasing spring 103 are shown. The unit shutter 102 is urged by the shutter urging spring 103 in the direction of the arrow in FIG. 17, and when the developing device 4 is set in the main body, the front end 102T is pushed and pushed in the direction of the arrow in FIG. Open the shutter. The recovered toner transported by the unit recovered toner transport screw 101 falls from the opening and is sent to the main body recovered toner transport path 123 through the deteriorated developer discharge path 121.

  Next, the shutter on the main body side will be described with reference to FIG. A main body shutter 105 is provided at the unit side joint portion of the deteriorated developer discharge path 121 and is urged by a shutter urging spring 106 in the direction of the arrow in the figure.

The operation of the shutter unit when the unit is attached / detached will be described with reference to FIGS. Regarding the configuration of the shutter unit, when the developing device 1004 is inserted into the image forming apparatus (FIG. 19), the unit-side shutter 102 moves in the direction of the arrow in FIG. Since the unit shutter biasing spring 103 is set stronger than the main unit shutter biasing spring 106, the unit shutter is opened first with almost no opening. Thereafter, the unit shutter is opened by abutting against the inner surface of the deteriorated developer discharge path 121. (FIG. 21) Since the unit shutter is opened last in this way, it is possible to prevent the collected toner from scattering into the image forming apparatus when the unit is attached or detached. Finally, at the same time as the developing device 4 is set in the drum direction, the main body side shutter 105 is closed and the gap with the unit shutter 102 can be closed. (Fig. 22)
Conventionally, an air path is formed by the plurality of deteriorated developer discharge paths 121 (ad) and the main body collected toner transport path 123. Due to the influence of air flow in the image forming apparatus, a part where the plurality of deteriorated developer discharge paths 121 (a to d) are provided as an intake port, and a different part is used as an exhaust port. Flows. With this air flow, the recovered toner sometimes flows backward from the portion that became the exhaust port.

  However, in this embodiment, since the shutter configuration as described above is provided for all the joint portions of the developing devices 1004a to 1044d and the deteriorated developer discharge paths 121a to 121d, the portions serving as the intake and exhaust ports are blocked. It is. Therefore, the collected toner does not flow backward from the deteriorated developer discharge paths 121a to 121d from the main body-collected toner conveyance path 123 on the main body side.

  Further, the main body side shutter 22b has a force that urges the cleaning device 1006 in the same direction as the direction in which the cleaning device 1006 moves from the retracted position to the operating position with respect to the photosensitive drum. For this reason, there is no resistance to the unit set, and there is an effect of assisting a smooth set.

  As described above, good image printing can be performed without scattering due to the collected toner in the image forming apparatus.

1 Photosensitive drum (image carrier)
2 Developer (Developer)
3 Primary charger 4 Cleaning device (cleaning means)
DESCRIPTION OF SYMBOLS 21 Degraded developer discharge path 22 Residual toner discharge path 23 1st collection toner conveyance path 24 1st collection toner conveyance screw 25 1st collection toner discharge path 31 Collection toner collection container 101 Unit collection toner conveyance screw 102 Unit shutter 103 Shutter urging spring 105 Main body shutter 106 Main body shutter urging spring 121 Deteriorated developer discharge path 122 Residual toner discharge path 123 Main body recovery toner conveyance path

Claims (5)

An image carrier for carrying an image;
A plurality of discharge ports for discharging toner, which are provided so as to be movable between a first position located at the time of image formation and a second position located away from the image carrier from the first position. Unit,
A conveyance path that is fixed to the apparatus main body, includes a plurality of openings for connecting to each of the plurality of units, and conveys the toner discharged from the plurality of units by merging. ,
The plurality of openings may be movable from the first position to the second position in a state where the discharge ports of the plurality of units are respectively connected to the plurality of openings. Formed corresponding to the movement area of the plurality of units,
An image forming apparatus comprising: a plurality of shutter members that respectively shield a part of the plurality of openings when the plurality of units are in the first position.   The plurality of shutter members are moved by an operation of inserting and removing the plurality of units into and from the plurality of openings, respectively, and are movable by an operation of moving the plurality of units to the first position and the second position. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided.   The plurality of shutter members include urging means for urging the plurality of shutter members toward the image carrier, and the plurality of shutter members are arranged in accordance with an operation of inserting the plurality of units into the plurality of openings, respectively. And a plurality of shutter members that move in a direction of retreating from the image carrier when the plurality of units abut against the tapered portions. The image forming apparatus according to 1 or 2.   A plurality of unit shutter members that respectively open and close the discharge ports, and the plurality of unit shutter members are in contact with the corresponding plurality of shutter members to close the discharge ports; The image forming apparatus according to claim 1, wherein the discharge port is opened by moving a shutter member and contacting the inner surface of the transport path. An image carrier for carrying an image;
A unit that is movably provided at a first position located at the time of image formation and a second position located away from the image carrier from the first position, and having a discharge port for discharging toner; And a plurality of image forming units for forming images,
A plurality of openings provided to be fixed to the apparatus main body and connected to the units provided in each of the plurality of image forming units; and from the units provided in each of the plurality of image forming units. A conveyance path for merging and conveying the discharged toner,
The opening is formed corresponding to the moving area of the unit so that the unit can move from the first position to the second position in a state where each of the discharge ports is connected to each of the openings. Has been
An image forming apparatus comprising: a plurality of shutter members that respectively shield a part of each of the openings when each of the units is in the first position.

Images