JP4534581B2 - Development device - Google Patents

Description

  The present invention relates to a developing device in which each developing device is sequentially opposed to an image carrier by rotation of a rotating member supporting a plurality of developing devices, and each developing device sequentially forms a toner image on the image carrier.

  In a rotary developing device in which a plurality of developing devices are supported by a rotary, the rotary devices are rotated so that each developing device is sequentially opposed to one photoconductor, and each developing device sequentially forms a toner image on one photoconductor. A method of recovering excess developer in the developing device by utilizing the rotation of the rotary has been devised (see, for example, Patent Document 1).

  In the developing device of Patent Document 1, a recovery nozzle protrudes from a recovery cartridge for recovering excess developer into the housing of the developing device. The recovery nozzle is refracted in the developing device. For this reason, the developer that has flowed into the collection nozzle is accumulated in the collection nozzle, and subsequent flow of excess developer in the developing device to the collection nozzle is hindered. As a result, insufficient recovery of the developer occurs.

  Further, the developer in the housing is given a predetermined inclination angle by the rotation of the rotary, but the angle of the recovery nozzle is set without taking into consideration the inclination angle of the developer at all. For this reason, it is difficult for excess developer to flow into the recovery nozzle, and the developer is insufficiently recovered.

  The developer in the housing accumulates on the end face of the recovery port when it flows into the recovery nozzle. When the rotary rotates in this state, the developer deposited on the end face of the recovery port falls to the recovery port. Excessive agent recovery.

Further, when the rotary is rotated, the developer flows into the recovery nozzle from the upstream side in the rotational direction of the rotary, so that the developer is excessively recovered.
JP 9-218575 A

  The present invention has been made in consideration of the above facts, and an object of the present invention is to accurately and efficiently recover the developer in the housing of the developing device from the recovery nozzle to the recovery portion.

The developing device according to claim 1, wherein the plurality of stirring members circulate while stirring the developer in the housing in parallel with the developing roll, and the developing roll is imaged with the developer stirred by the stirring member. Excess developer in the developer from a plurality of developers that visualizes the electrostatic latent image on the carrier, and a recovery nozzle that protrudes from the housing toward the developer circulation path in the developer. A plurality of collecting units to be collected, a plurality of the developing units and a plurality of the collecting units are supported and rotated, and each developing unit is sequentially opposed to the image carrier, and excessive development in each developing unit And a rotating body that moves the agent to a collection position for collecting the agent to the collection unit, wherein the collection nozzle is opened with a tip serving as a collection port when the developer is located at the collection position. Is tilted by the rotation of the rotating body Characterized in that it is arranged obliquely in the inclined direction of the image agent.

  In the developing device according to the first aspect, a plurality of developing devices are carried on a rotating member, and the rotating members rotate so that each developing device is sequentially opposed to the image bearing member. When each developing device is rotated to the developing position facing the image carrier, the plurality of stirring members are rotated, the developer in the housing is circulated while being stirred in parallel with the developing roll, and the developing roll is rotated. Then, the electrostatic latent image on the image bearing member is visualized with the developer stirred by the stirring member.

  In addition, a plurality of recovery units are carried on the rotating body, and the rotating body rotates, so that excess developer in the developing device protrudes from the housing toward the developer circulation path at a predetermined recovery position. It is recovered from the recovery nozzle to the recovery unit.

Here, when the developing device is located at the collection position, the collection nozzle that is opened with the tip serving as the collection port is inclined in the direction of inclination of the developer inclined by the rotation of the rotating body (along the inclined surface). Be placed. Therefore, the developer covering the recovery port of the recovery nozzle can flow into the recovery nozzle by its own weight, and the amount of developer in the housing can be reliably maintained at a predetermined amount.

A developing device according to a second aspect is the developing device according to the first aspect, wherein the inclination angle of the recovery nozzle is larger than the inclination angle of the developer .

In the developing device according to claim 2, since the inclination angle of the recovery nozzle is larger than the inclination angle of the developer, the developer covering the recovery port of the recovery nozzle can be caused to flow into the recovery nozzle by its own weight. . Therefore, the amount of developer in the housing can be reliably maintained at a predetermined amount.

A developing device according to a third aspect is the developing device according to the first or second aspect, wherein the inclination angle of the recovery nozzle is not less than the repose angle of the developer .

In the developing device according to the third aspect, by setting the inclination angle of the recovery nozzle to be equal to or greater than the repose angle of the developer, the developer covering the recovery port of the recovery nozzle can easily flow into the recovery nozzle.

The developing device according to claim 4 is the developing device according to any one of claims 1 to 3, wherein a cross-sectional shape of the recovery nozzle gradually expands from the recovery port to the outside of the housing. It is characterized by being.

In the developing device according to the fourth aspect, the sectional shape of the recovery nozzle is gradually enlarged from the recovery port to the outside of the housing. As a result, the developer can easily flow from the collection port of the collection nozzle to the outside of the housing, and excess developer can flow into the collection nozzle one after another, so that insufficient collection of the developer can be prevented.

The developing device according to claim 5 is the developing device according to any one of claims 1 to 4, the corner portion of the recovery port end surface of the recovery nozzle, outside of the recovery nozzle An inclined surface that is inclined toward the surface is formed .

In the developing device according to claim 5, an inclined surface inclined toward the outside of the recovery port is formed on the recovery port end surface of the recovery nozzle, and the developer covering the recovery port end surface of the recovery nozzle has an inclined surface. Slip and fall outside the collection port. This can prevent excessive recovery of the developer.

A developing device according to a sixth aspect is the developing device according to any one of the first to fifth aspects, wherein when the developing device moves from the collection position by the rotation of the rotating body, the developing device Inflow prevention means for preventing the agent from flowing into the recovery nozzle from the downstream side in the rotation direction is provided .

  The developing device according to claim 6 is provided with inflow prevention means, and when the developing device moves from the collection position by the rotation of the rotating body, the development deposited on the downstream side in the rotation direction of the rotating body from the collecting nozzle. The agent is prevented from flowing into the recovery nozzle. This can prevent excessive recovery of the developer.

The developing device according to claim 7, a developing device according to claim 6, wherein the inflow preventing means is a said collection port end face standing wall of the recovery nozzle, said wall said recovery It is provided only on one side of the mouth end face on the downstream side in the rotation direction.

  In the developing device according to claim 7, a wall is erected on the downstream side in the rotation direction of the collection port end face of the collection nozzle, and when the developing device moves from the collection position by the rotation of the rotating body, The developer deposited on the downstream side in the rotation direction is prevented from flowing into the recovery nozzle.

  Here, the wall is provided only on one side downstream of the collection port end surface in the rotation direction, and no step is formed on the upstream side of the collection port end surface in the rotation direction, so that the developer hardly accumulates on the collection port end surface. It has become.

The developing device according to claim 8 is the developing device according to any one of claims 1 to 5, wherein the end face of the recovery port of the recovery nozzle is formed flat. To do.

  If a step is formed on the recovery nozzle end face of the recovery nozzle, the developer easily accumulates at the corner of the step. However, in the developing device according to claim 8, the recovery nozzle end face of the recovery nozzle is formed flat. Therefore, the developer is difficult to deposit on the end face of the collection port.

  Since the present invention has the above-described configuration, the developer in the housing of the developing device can be efficiently and efficiently collected from the collection nozzle to the collection unit.

  An embodiment of the present invention will be described below with reference to the drawings.

  1 and 2 show a four-cycle full-color printer 10 as an image forming apparatus. Inside the printer 10, a photosensitive drum 12 as an image carrier is rotatably disposed at an upper right part slightly from the center. As this photosensitive drum 12, for example, a drum made of a conductive cylinder having a diameter of about 47 mm whose surface is coated with a photosensitive layer made of OPC or the like is used. It is rotationally driven at a process speed of about 150 mm / sec.

  The surface of the photosensitive drum 12 is charged to a predetermined potential by a charging roll 14 disposed almost directly below the photosensitive drum 12, and then an ROS 16 (Raster Output Scanner) serving as an exposure device disposed below the charging roll 14. ), Image exposure with a laser beam (LB) is performed, and an electrostatic latent image corresponding to image information is formed.

  The electrostatic latent image formed on the photosensitive drum 12 passes through the developing units 18Y, 18M, 18C, and 18K for each color of yellow (Y), magenta (M), cyan (C), and black (K) in the circumferential direction. The toner is developed by a rotary developing device 18 arranged along the toner image to be a toner image of a predetermined color.

  At this time, the charging, exposure, and development processes are repeated a predetermined number of times on the surface of the photosensitive drum 12 in accordance with the color of the image to be formed. In the rotary developing device 18, the corresponding color developing devices 18 </ b> Y, 18 </ b> M, 18 </ b> C, and 18 </ b> K move to a developing position facing the photosensitive drum 12.

  For example, when a full-color image is formed, the charging, exposing, and developing processes are performed on the surface of the photosensitive drum 12 in yellow (Y), magenta (M), cyan (C), and black (K) colors. The toner image corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) is sequentially formed on the surface of the photosensitive drum 12. .

  When the toner image is formed, the number of rotations of the photosensitive drum 12 varies depending on the size of the image. For example, in the case of A4 size, one image is obtained by rotating the photosensitive drum 12 three times. It is formed. That is, a toner image corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) is formed on the surface of the photosensitive drum 12 every time the photosensitive drum 12 rotates three times. Is done.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images sequentially formed on the photosensitive drum 12 are transferred onto the outer periphery of the photosensitive drum 12 as an intermediate transfer member. At the primary transfer position where the belt 20 is wound, the primary transfer is performed by the primary transfer roll 22 while being superimposed on the intermediate transfer belt 20.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred in multiple onto the intermediate transfer belt 20 are recorded on a recording sheet 24 fed at a predetermined timing. Secondary transfer is collectively performed by the secondary transfer roll 26.

  On the other hand, the recording paper 24 is fed from a paper feed cassette 28 disposed at the bottom of the printer 10 by a pickup roll 30 and is fed one by one by a feed roll 32 and a retard roll 34 to be registered. The roller 36 is conveyed to the secondary transfer position of the intermediate transfer belt 20 in synchronization with the toner image transferred onto the intermediate transfer belt 20.

  The intermediate transfer belt 20 includes a wrap-in roll 38 that specifies the wrap position of the intermediate transfer belt 20 on the upstream side in the rotational direction of the photosensitive drum 12 and a toner image formed on the photosensitive drum 12 as an intermediate transfer belt. A primary transfer roll 22 that is transferred onto the intermediate transfer belt 20, a wrap-out roll 40 that specifies the wrap position of the intermediate transfer belt 20 on the downstream side of the wrap position, and a backup that contacts the secondary transfer roll 26 via the intermediate transfer belt 20. The roll 42, the first cleaning backup roll 46 facing the cleaning device 44 of the intermediate transfer belt 20, and the second cleaning backup roll 48 are stretched with a predetermined tension and have a predetermined process speed (about 150 mm / sec), for example, as the photosensitive drum 12 rotates. It is driven Te.

  Here, in order to reduce the size of the printer 10, the intermediate transfer belt 20 is configured such that the cross-sectional shape on which the intermediate transfer belt 20 is stretched becomes a flat and elongated substantially trapezoidal shape.

  The intermediate transfer belt 20 includes a photosensitive drum 12, a charging roll 14, an intermediate transfer belt 20, a plurality of rolls 22, 38, 40, 42, 46, and 48 that stretch the intermediate transfer belt 20, and an intermediate transfer belt. The image forming unit 52 is constituted by a cleaning device 44 for 20 and a cleaning device 78 for the photosensitive drum 12 described later, and is integrally provided.

  For this reason, the entire image forming unit 52 can be removed from the printer 10 by opening the upper cover 54 of the printer 10 and lifting the handle (not shown) provided on the upper portion of the image forming unit 52 by hand.

  On the other hand, the cleaning device 44 for the intermediate transfer belt 20 includes a scraper 58 disposed so as to come into contact with the surface of the intermediate transfer belt 20 stretched by the first cleaning backup roll 46, and a second cleaning backup roll 48. A cleaning brush 60 disposed so as to be in pressure contact with the surface of the stretched intermediate transfer belt 20, and residual toner and paper dust removed by the scraper 58 and the cleaning brush 60 are contained in the cleaning device 44. It has come to be collected.

  The cleaning device 44 is disposed so as to be able to swing counterclockwise in the drawing with the swing shaft 62 as the center, and until the secondary transfer of the final color toner image is completed, the intermediate transfer belt is provided. It is configured to retreat to a position separated from the surface of the surface 20 and to contact the surface of the intermediate transfer belt 20 when the secondary transfer of the final color toner image is completed.

  Further, the recording paper 24 onto which the toner image is transferred from the intermediate transfer belt 20 is conveyed to a fixing device 64, and the fixing device 64 fixes the toner image on the recording paper 24 with heat and pressure. In this case, the paper is discharged as it is onto a discharge tray 68 provided at the top of the printer 10 by a discharge roll 66.

  On the other hand, in the case of double-sided printing, the recording paper 24 on which the toner image is fixed by the fixing device 64 is not directly discharged onto the discharge tray 68 by the discharge roll 66, but the rear end of the recording paper 24 by the discharge roll 66. The paper discharge path 66 is reversed in a state where the section is held, and the conveyance path of the recording paper 24 is switched to the double-sided paper conveyance path 70, and the conveyance roll 72 disposed in the double-sided paper conveyance path 70 is used. Then, the recording paper 24 is conveyed again to the secondary transfer position of the intermediate transfer belt 20 with the front and back sides of the recording paper 24 reversed, and an image is formed on the back surface of the recording paper 24.

  Further, in the full color printer, a manual feed tray 74 can be attached to the side surface of the printer 10 so as to be freely opened and closed as an option. An arbitrary size and type of recording paper 24 placed on the manual feed tray 74 is fed by a paper feed roll 76, and the secondary transfer position of the intermediate transfer belt 20 via a transport roll 72 and a registration roll 36. The image can be formed on the recording paper 24 of any size and type.

  The surface of the photosensitive drum 12 after the toner image transfer process is completed is cleaned by the cleaning blade 80 of the cleaning device 78 disposed obliquely below the photosensitive drum 12 every time the photosensitive drum 12 rotates once. Residual toner is removed to prepare for the next image forming process.

  On the other hand, FIG. 3 and FIG. 4 show a rotary developing device 18. FIG. 3 shows a state where one developing device 18Y and developer cartridge 82Y are mounted on the developing device 18 for convenience.

  The developing device 18 includes a rotary 39 that supports the developing devices 18Y, M, C, and K. The rotary 39 is provided with a cylindrical rotary shaft member 41. The rotary 39 is pivotally supported around the rotary shaft member 41 so as to be able to rotate counterclockwise (in the direction of arrow A). Further, a front flange member 43 is provided at the front end of the rotary shaft member 41 in the longitudinal direction, and a rear side is provided at the rear end of the rotary shaft member 41 in the longitudinal direction of the drawing. The flange member 45 is provided.

  The cylindrical space S formed by the rotary shaft member 41 and the flange members 43 and 45 is divided into four every 90 degrees by the partition member 47.

  In the space partitioned by the partition member 47, four developing devices 18Y, 18M, 18C, and 18K of yellow (Y), magenta (M), cyan (C), and black (K) are clockwise in the circumferential direction. Each is implemented along.

  These developing units 18Y, 18M, 18C and 18K correspond to the developing units 18Y, 18M, 18C and 18K, and develop yellow (Y), magenta (M), cyan (C) and black (K). The developer cartridges 82Y, 82M, 82C, and 82K are mounted, respectively, and a new developer is supplied from the corresponding developer cartridges 82Y, 82M, 82C, and 82K (see FIGS. 5 and 6).

  Here, the developing devices 18Y, 18M, 18C, and 18K and the developer cartridges 82Y, 82M, 82C, and 82K are all configured in the same manner. Therefore, here, the yellow (Y) developing device 18Y and the developer cartridge 82Y. Will be described as an example.

  As shown in FIGS. 8 and 9, the housing 150 of the developing device 18 </ b> Y has a long box shape along the direction orthogonal to the recording sheet to be conveyed, and is substantially in the center in the width direction of the housing 150. The partition wall 152 is erected to partition the housing 150 into a space 154 and a space 156. Clearances 158 and 160 are provided between both ends of the partition wall 152 and the peripheral wall of the housing 150, and the space 154 and the space 156 communicate with each other.

  A spiral auger 90 is disposed in the space 154 along the longitudinal direction of the housing 150, and a spiral auger 92 is disposed in the space 156 in parallel with the spiral auger 90. The spiral augers 90 and 92 include a rotation shaft 162 and are rotatably supported on the peripheral wall of the housing 150. Gears 166 and 168 are fixed to end portions of the rotating shaft 162, respectively.

  Further, as shown in FIGS. 8 and 9, forward spiral blades 164 formed in a spiral shape are provided around the rotation shaft 162 of the spiral augers 90 and 92 (described later), from a motor (not shown). Is transmitted to the gears 166 and 168, and the spiral augers 90 and 92 are rotated through the gears 166 and 168, respectively. Be transported.

  Further, on the end side downstream of the spiral augers 90 and 92 in the transport direction, there are provided one or two spiral reverse spiral blades 188 directed in the direction opposite to the spiral direction of the forward spiral blade 164. The developer conveyed by the spiral blade 164 is pushed back in the reverse direction.

  The ends of the spiral augers 90 and 92 pass through the peripheral wall of the developing device 18Y, and the space between the rotating shaft 162 and the peripheral wall of the developing device 18Y is sealed by packing so that the developer in the housing 150 does not leak. However, if the developer conveying force is large, the developer in the developing device 18Y may leak to the outside.

  For this reason, by providing a reverse spiral blade 188 on the downstream side of the spiral augers 90 and 92 in the transport direction so as to push back the transported developer, the transport force of the developer at the ends of the spiral augers 90 and 92 is reduced. In order to prevent the developer from leaking outside.

  On the other hand, a developing roll 88 is disposed obliquely above the spiral auger 92 along the longitudinal direction of the housing 150, and is rotatably supported on the peripheral wall of the housing 150. A gear 89 is fixed to the end of the developing roll 88, and a rotational force from a motor (not shown) is transmitted to the gear 89 so that the developing roll 88 rotates through the gear 89.

  At this time, the developer conveyed to the space 156 by the spiral auger 90 through the gap 160 is conveyed in the space 156 in the direction of the arrow by the spiral auger 92 and is equally supplied to the developing roll 88. The layer thickness of the developer supplied to the surface of the developing roll 88 is regulated by a layer thickness regulating member 96 (see FIG. 4).

  Incidentally, the housing 150 is provided with a cover 170, and the cover 170 covers the space 154 and the upper part of the space 156. In this state, as shown in FIG. 4, a part of the developing roll 88 is exposed and can face the photosensitive drum 12.

  The developing roll 88 adsorbs the carrier contained in the developer with a magnetic force, forms a magnetic brush of the developer on the surface, and conveys the toner adsorbed on the carrier to a developing area facing the photosensitive drum 12. Then, the electrostatic latent image formed on the photosensitive drum 12 is visualized by a developer magnetic brush made of a carrier and toner formed on the surface of the developing roll 88.

  In this embodiment, a two-component developer composed of a toner and a carrier is used as the developer. However, as the developer, it is sufficient that the developer contains at least a toner. Of course, it is also possible to use the developer.

  As shown in FIGS. 6 and 7, an arc receiving plate 172 curved in a substantially arc shape is provided on the outer surface of one end side of the cover 170. In the arc receiving plate 172, a supply port 174 for supplying developer in the developer cartridge 82Y, which will be described later, to the housing 150 and excess developer exceeding a predetermined amount in the housing 150 are discharged into the developer cartridge 82Y. A discharge port 176 is formed.

  Further, the arc receiving plate 172 is provided with a shutter plate 114 so as to be slidable along the circumferential direction of the arc receiving plate 172. The shutter plate 114 is formed with a communication port 178 capable of communicating with the discharge port 176, The developer in the housing 150 communicates with the discharge port 176 and is discharged into the developer cartridge 82Y.

  Here, in the shutter plate 114, the communication port 178 and the discharge port 176 are in communication with each other, the developer port 174 is opened in a state where the developer in the housing 150 can be discharged into the developer cartridge 82Y, and the housing 150 It is possible to supply new developer inside.

  On the other hand, as shown in FIGS. 8 and 9, a transport path 180 is provided on the outer surface of the cover 170, and an external supply port 181 communicating with the supply port 174 is provided at one end of the transport path 180. The other end of the conveyance path 180 is provided with an internal supply port 182 communicating with the upstream side of the spiral auger 90 in the conveyance direction.

  A spiral auger 94 smaller in diameter than the spiral augers 90 and 92 is rotatably supported in the transport path 180, and a gear 195 is fixed to the end of the rotating shaft 194 of the spiral auger 94. . In addition, a forward spiral blade 192 formed in a spiral shape is provided around the rotation shaft 194. When the rotational force is transmitted to the gear 195 and the spiral auger 94 rotates via the gear 195, the replenishing port 174 and the outside are provided. The developer replenished into the conveyance path 180 through the supply port 181 is conveyed to the internal supply port 182 by the forward spiral blade 192 and supplied into the housing 150.

  On the other hand, as shown in FIGS. 4, 6 and 10, the developer cartridge 82Y is constituted by a long cylindrical body having a non-circular cross section. A partition cap 106 is provided inside the developer cartridge 82Y, and is divided into a developer storage portion 102 that stores new developer and a developer recovery portion 104 that recovers excess developer. ing.

  A supply port 108 for supplying a new developer into the housing 150 is provided at the end of the developer accommodating portion 102 and can communicate with a supply port 174 provided on the outer surface of the housing 150. . On the other hand, the developer recovery section 104 is provided with a recovery port 184 for recovering the developer discharged from the housing 150, and the communication port 178 (see FIG. 7) formed in the shutter plate 114 is an arc. The recovery port 184 can communicate with the communication port 178 and the discharge port 176 in a state where it communicates with the discharge port 176 formed in the receiving plate 172.

  Here, as shown in FIG. 8, a recovery nozzle 186 projects from the peripheral edge of the discharge port 176 into the housing 150, and the developer in the housing 150 passes through the recovery nozzle 186 to the discharge port 176. Guided.

  As shown in FIG. 12A, when the developing device 18Y is located at the developing position (position A in FIG. 4) where the developing roll 88 faces the photosensitive drum 12, the recovery nozzle 186 faces obliquely downward. The angle is set to For this reason, when the developing device 18Y is located at the developing position, the developer in the housing 150 is not collected by the developer collecting unit 104.

  Then, as shown in FIG. 12B, when the developing unit 18Y moves 90 ° from the developing position, the collection nozzle 186 is angled so as to face obliquely upward. The inclination angle of the collection nozzle 186 is set to be steeper than the inclination angle of the developer in the housing 150. Therefore, as shown in FIG. 12C, when the amount of developer contained in the housing 150 increases, the rotation of the rotary 39 causes the developing device 18Y to move counterclockwise by about 90 ° from the developing position. In addition, the developer at a position higher than the height of the front end surface of the recovery nozzle 186 is discharged through the recovery nozzle 186 to the developer recovery unit 104 via the discharge port 176, the communication port 178 and the recovery port 184.

  This is a so-called trickle system, and the developer charging performance is gradually reduced to prevent the deterioration of the charging performance of the developer and the developer replacement interval is extended. This is a system in which development is carried out while discharging the developer (which contains many deteriorated carriers) from the inside of the developing device.

  Incidentally, as shown in FIGS. 6 and 10, on the outer periphery (partly including the developer accommodating portion 102) of the developer collecting portion 104 formed in the cylindrical shape of the developer cartridge 82Y, the developer accommodating portion 102 is provided. A shutter member 128 that opens and closes the supply port 108 and the recovery port 184 of the developer recovery unit 104 is rotatably fitted along the circumferential direction.

  As shown in FIGS. 10 and 11, the shutter member 128 has a supply opening 130 and a collection opening 132 at positions corresponding to the supply port 108 and the collection port 184 of the developer cartridge 82Y, respectively. The supply port 108 and the recovery port 184 of the developer cartridge 82Y can be opened and closed simultaneously by rotating the shutter member 128 along the outer periphery of the developer recovery unit 104 of the developer cartridge 82Y. It has become.

  Further, the shutter member 128 is configured to rotate the shutter member 128 to a part in the circumferential direction of the shutter member 128 and to hold the shutter member 128 and attach the developer cartridge 82Y to the developing device 18Y. The handle 134 protrudes outward in the radial direction.

  In the handle 134, when the developer cartridge 82Y is mounted on the developing device 18Y and the supply port 108 and the recovery port 184 are opened, the top portion 134A coincides with the corner portion 83 of the developer cartridge 82Y (A in FIG. 4). In the state in which the supply port 108 and the recovery port 184 are closed, the top portion 134A and the corner portion 83 are arranged in a shifted state, and the handle 134 protrudes from the outer periphery of the developing device 18.

  Further, as shown in FIG. 11, in a state where the developer cartridge 82Y is removed from the developing device 18Y, the movement of the shutter member 128 is restricted so that the supply port 108 and the recovery port 184 of the developer cartridge 82Y are not accidentally opened. It has become. Further, as shown in FIG. 5, when the developer cartridge 82Y is mounted at a predetermined position of the developing device 18Y and the supply port 108 and the recovery port 184 of the developer cartridge 82Y are opened, the developer cartridge 82Y is It cannot be removed from the developing unit 18Y.

  In this embodiment, when the developer cartridge 82Y is mounted in a predetermined position of the developing device 18Y, the developer cartridge 82Y is rotated from the outside in the radial direction of the developing device 18 shown in FIG. By sliding along the housing 150 of the developing device 18Y toward the shaft member 41, the developer cartridge 82Y can be easily attached to and detached from the developing device 18Y.

  Further, when the developer cartridge 82Y is replaced with a new one, as shown in FIG. 2, the developing device 18 is stopped so that the developer cartridge 82Y to be replaced is disposed at the replacement position B, and the printer 10 The side cover 97 provided on the side surface is opened, and the developer cartridge 82Y to be replaced is taken out.

  Here, as shown in FIG. 6, when the developer cartridge 82Y is removed from the developing device 18Y, the handle 134 of the shutter member 128 is rotated by hand, and the shutter member 128 is rotated clockwise. As the shutter member 128 rotates, the supply port 108 and the recovery port 184 of the developer cartridge 82Y are closed.

  Then, with the handle 134 of the shutter member 128 stopped moving, the supply port 108 and the collection port 184 of the developer cartridge 82Y are completely closed. In this state, the developer cartridge 82Y can be detached from the developing device 18Y.

  Next, the main part of the developing device according to the embodiment of the present invention will be described.

  As shown in FIG. 9, the developing unit 18Y (the developing units 18Y, 18M, 18C, and 18K are all configured in the same manner, and therefore, here, the yellow (Y) developing unit 18Y will be described as an example. The spiral auger 90 disposed in the inside is provided with a forward spiral blade 164 formed in a spiral shape around the rotation shaft 162, and the forward spiral blade 164 is spiraled by the rotation of the spiral auger 90. Is shaped in the direction of the arrow (forward direction). With this spiral shape, the developer in the space 154 is conveyed in the direction of the arrow while being stirred.

  On the other hand, as shown in FIG. 4, a recovery nozzle 186 protrudes into the housing 150 from the peripheral edge of the discharge port 176 formed in the cover 170 of the developing device 18 </ b> Y, and the development accommodated in the housing 150. When the amount of the developer increases, when the developing device 18Y moves to the position B in FIG. 4 by the rotation of the developing device 18, the developer at a position higher than the height of the front end surface of the recovery nozzle 186 passes through the recovery nozzle 186. The toner is discharged to the developer recovery unit 104 through the discharge port 176, the communication port 178, and the recovery port 184.

  Here, FIG. 13 shows a state when the developing unit 18Y is located at the collection position. The developer in the housing 150 that has increased in volume as a result of being supplied from the developer cartridge 82Y as a result of printing is changed in the accumulation state by the rotational force of the rotary 39, and the developer surface becomes the inclined surface L. At this time, the inclination angle β of the inclined surface L of the developer is an angle of repose that is a physical property value of the powdery deposit.

  The recovery nozzle 186 is arranged along the developer inclined surface L, and the inclination angle α of the recovery nozzle 186 is set larger than the inclination angle β of the developer. For this reason, the developer covered on the recovery port end surface 186A (see FIG. 14) of the recovery nozzle 186 falls from the recovery port 186B by its own weight, passes through the recovery nozzle 186, passes through the discharge port 176, the communication port 178, and the recovery port 184. Then, it is discharged to the developer recovery unit 104 (see FIG. 4). Thus, when the developing device 18Y is positioned at the collection position, the developer amount in the housing 150 can be reliably maintained at a predetermined amount indicated by a dotted line L ′ in the drawing.

  Further, an inclined surface 186C is formed on the recovery port end surface 186A by chamfering the corner of the recovery port end surface 186A. The inclined surface 186C is provided on one side upstream of the rotary 39 in the rotation direction. For this reason, as shown in FIG. 14A, after the excess developer is recovered, the developer covered under the recovery port end face 186A is rotated by the rotary 39 as shown in FIG. 14B. Then, it slides down from the inclined surface 186C to the outside of the recovery port 186B. Thereby, although it is a small amount, it is possible to prevent an excessive recovery due to the continuous recovery of the developer deposited on the recovery port end face 186A.

  As shown in FIGS. 13 and 14, the recovery nozzle 186 is formed linearly from the recovery port 186 </ b> B to the outside of the housing 150. Therefore, the developer that has flowed into the collection nozzle 186 flows to the developer collection unit 104 without being deposited in the middle of the collection nozzle 186. Accordingly, excess developer can be made to flow into the recovery nozzle 186 one after another, so that insufficient recovery of the developer can be prevented, and the amount of developer in the housing 150 can be quickly set to a predetermined amount.

  Further, the recovery nozzle 186 has a cross-sectional shape that gradually expands from the recovery port 186 </ b> B to the outside of the housing 150. In other words, the flow path of the recovery nozzle 186 expands from the recovery port 186 </ b> B to the back, so that the developer can easily flow through the recovery nozzle 186.

  Furthermore, if a step is formed on the recovery port end surface 186A of the recovery nozzle 186, the developer easily accumulates at the corner of the step, but the recovery port end surface 186A of the recovery nozzle 186 is formed flat. Further, it is difficult for the developer to be deposited on the recovery port end face 186A, and variations in recovery can be suppressed.

  Next, a recovery nozzle 200 that is a modification of the recovery nozzle 186 will be described.

  As shown in FIG. 15A, in the recovery nozzle 200, a wall 200B is erected from the recovery port end surface 200A. This wall 200B is disposed downstream of the recovery port 200C in the rotation direction. For this reason, as shown in FIG. 15B, after the excess developer in the housing 150 is collected, the developing unit 18Y is moved from the collection position by the rotation of the rotary 39 as shown in FIG. At this time, the developer deposited on the downstream side in the rotation direction from the recovery nozzle 200 is prevented from flowing into the recovery port 200C by the wall 200B. Thereby, unintended recovery of the developer due to the rotation of the rotary 39 can be prevented.

  Here, in the recovery nozzle 200, the wall 200B is provided only on one side downstream of the recovery port end surface 200A in the rotation direction, and no step is formed on the upstream side of the recovery port end surface 200A in the rotation direction. It is difficult to deposit on the end face 200A. For this reason, it is possible to prevent excessive collection due to developer accumulation on the collection port end surface 200A.

1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention. 1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention, showing a state where an image forming unit is removed. FIG. 1 is a perspective view showing a rotary developing device constituting an image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view showing a rotary developing device constituting an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view showing a developing device and a developer cartridge of the developing device according to the embodiment of the present invention. FIG. 3 is an exploded perspective view showing a developing device and a developer cartridge of the developing device according to the embodiment of the present invention. It is a perspective view which shows the developing device of the developing device which concerns on embodiment of this invention. FIG. 2 is an exploded perspective view showing a housing and a cover of a developing device of the developing device according to the embodiment of the present invention. FIG. 4 is a plan view of the housing side of the developing device of the developing device according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of a developer cartridge mounted on a developing device of a developing device according to an embodiment of the present invention. FIG. 4 is a perspective view of a developer cartridge mounted on a developing device of a developing device according to an embodiment of the present invention. FIGS. 4A to 4C are cross-sectional views illustrating a developing device and a developer cartridge of a developing device according to an embodiment of the present invention. It is sectional drawing of the side surface by the side of the housing of the image development apparatus of the image development apparatus concerning embodiment of this invention. (A), (B) is sectional drawing of the collection | recovery nozzle of the developing device of the developing device which concerns on embodiment of this invention. (A)-(C) are sectional drawings of the collection | recovery nozzle of the developing device of the developing device which concerns on embodiment of this invention.

Explanation of symbols

12 Photosensitive drum (image carrier)
18 Developing Device 18C Developing Device 18M Developing Device 18Y Developing Device 18K Developing Device 39 Rotary (Rotating Body)
88 Developing roll 90 Spiral auger (stirring member)
92 Spiral auger (stirring member)
104 Developer collection unit (collection unit)
186 Collection nozzle 186A Collection port end surface 186B Collection port 186C Inclined surface 200 Collection nozzle 200A Collection port end surface 200B Wall (inflow prevention means)
200C Recovery port L Inclined surface α Inclination angle β Inclination angle

Claims (8)

A plurality of stirring members circulate while stirring the developer in the housing in parallel with the developing roll, and the developing roll reveals an electrostatic latent image on the image carrier with the developer stirred by the stirring member. A plurality of developing devices to be imaged;
A plurality of recovery portions for recovering excess developer in the developer unit from a recovery nozzle protruding from the housing toward the developer circulation path in the developer unit;
A plurality of developing units and a plurality of collecting units are carried and rotated, and each developing unit is sequentially opposed to the image carrier, and excess developer in each developing unit is collected to the collecting unit. A rotating body to be moved to the collection position;
A developing device comprising:
When the developing device is located at the recovery position, the recovery nozzle having an opening with a front end serving as a recovery port is inclined and arranged in a direction of inclination of the developer inclined by the rotation of the rotating body. Developing device. The developing device according to claim 1, wherein an inclination angle of the recovery nozzle is larger than an inclination angle of the developer. The developing device according to claim 1, wherein an inclination angle of the recovery nozzle is equal to or greater than a repose angle of the developer. The developing device according to claim 1 , wherein a cross-sectional shape of the recovery nozzle is gradually enlarged from the recovery port to the outside of the housing . The corner portion of the recovery port end surface of the recovery nozzle, according to any one of claims 1 to 4, characterized in that the inclined surface inclined toward the outside of the recovery nozzle is formed Development device. Claims wherein the developing device when moving from the recovery position by the rotation of the rotary member, a developing agent, characterized in that the inflow preventing means for preventing the flow from the downstream side in the rotating direction to the recovery nozzle is provided The developing device according to any one of claims 1 to 5 . Wherein the inflow preventing means, said a said recovery port end surface upstanding walls of the recovery nozzle, wherein said wall is provided only on one side of the downstream side in the rotational direction of the recovery port end surface Item 7. The developing device according to Item 6. The developing device according to claim 1 , wherein an end face of the recovery port of the recovery nozzle is formed flat .

Images