JP4946938B2 - Developer transport device, developing device using the same, and image forming apparatus - Google Patents

Description

  The present invention relates to a developer conveying developer conveying device, a developing device using the same, and an image forming apparatus.

JP 2000-29313 A

  Conventionally, as this type of developer conveying device, for example, a device disclosed in Japanese Patent Application Laid-Open No. 2000-29313 has already been proposed.

  A toner return device of an image forming apparatus according to Japanese Patent Laid-Open No. 2000-29313 is a toner return device of an image forming apparatus for returning residual toner collected by a cleaning device to a developing device, and an entrance is the cleaning device A conduit disposed in the vicinity and an outlet disposed in the vicinity of the developing device; and a spiral blade member for toner conveyance on the outer periphery of the conduit that is rotatably disposed along the axial direction in the conduit. And a toner conveying member having a toner conveying force on the outlet side of the conduit larger than the toner conveying force on the inlet side.

  The problem to be solved by the present invention is to provide a developer conveying device capable of suppressing variations in the developer supply amount, a developing device using the same, and an image forming apparatus.

That is, the invention described in claim 1 is provided in parallel with a stirring auger that transports the developer containing at least the toner while stirring, and a developer transport path for transporting the developer,
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
Without being provided with a transport vane on the outer periphery of the rotation shaft over the region corresponding to the supply port and the region upstream of the supply port in the developer transport direction. Also, the developer is transported toward the supply port by the pressing force of the developer transported from the upstream side in the developer transport direction, so that a developer dense portion where the developer is denser than the upstream side is provided. A provided developer conveying member;
A developer transport device comprising:

According to a second aspect of the present invention, the developer transport member is provided with a developer transported by the developer transport member at a downstream end of the supply port along the developer transport direction. The developer conveying device according to claim 1 , further comprising a return conveying blade that conveys upstream in the developer conveying direction .

  Further, the invention described in claim 3 is characterized in that a developer loosening member for loosening the developer staying in the developer dense portion is provided in the developer dense portion of the developer conveying member. The developer conveying device according to 1 or 2.

  According to a fourth aspect of the present invention, in the developer conveying device according to the third aspect, the developer loosening member is provided upstream of the supply port in the developer conveying direction. is there.

Furthermore, the invention described in claim 5 includes a developer container that contains a developer containing at least toner,
A developer carrier that develops an electrostatic latent image formed on the image carrier by the developer supplied from the developer container , and a developer that is supplied to the developer carrier is conveyed while stirring. A developing device housing having a stirring auger ;
A developer transport path that is provided in parallel with the stirring auger and transports the developer from the developer container to the developing device housing;
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
A member disposed inside the developer transport path for transporting the developer from the developer container to the developer supply port of the developing device housing and corresponding to the supply port of the developing device housing Development transported from the upstream side in the developer transport direction from the supply port of the developing device housing without providing transport blades on the outer periphery of the rotating shaft over the upstream region in the developer transport direction from the region and the supply port. A developer conveying member provided with a developer dense portion where the developer is denser than the upstream side by conveying the developer toward the supply port by the pressing force of the agent;
Is a developing device.

According to a sixth aspect of the present invention, an image carrier on which an electrostatic latent image corresponding to image information is formed on the surface;
A developer container containing a developer containing at least toner;
A developer carrier that develops an electrostatic latent image formed on the image carrier by the developer supplied from the developer container , and a developer that is supplied to the developer carrier is conveyed while stirring. A developing device housing having a stirring auger;
A developer transport path that is provided in parallel with the stirring auger and transports the developer from the developer container to the developing device housing;
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
A member disposed inside the developer transport path for transporting the developer from the developer container to the developer supply port of the developing device housing and corresponding to the supply port of the developing device housing Development transported from the upstream side in the developer transport direction from the supply port of the developing device housing without providing transport blades on the outer periphery of the rotating shaft over the upstream region in the developer transport direction from the region and the supply port. A developer conveying member provided with a developer dense portion where the developer is denser than the upstream side by conveying the developer toward the supply port by the pressing force of the agent;
An image forming apparatus comprising:

  According to the first aspect of the present invention, it is possible to suppress variations in the developer supply amount.

  According to the second aspect of the present invention, the developer can be made sufficiently dense, and the variation in the developer supply amount due to the variation in the density of the developer can be further suppressed.

  Furthermore, according to the third aspect of the present invention, it is possible to avoid aggregation of the developer in the developer dense portion.

  Further, according to the invention described in claim 4, it is possible to sufficiently obtain the developer loosening effect.

  Furthermore, according to the invention described in claim 5, it is possible to provide a developing device having the same effect as the developer conveying device described in claim 1.

  According to the sixth aspect of the present invention, it is possible to provide an image forming apparatus that exhibits the same effect as the developer conveying apparatus according to the first aspect.

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

Embodiment 1
FIG. 2 shows a tandem type full-color printer as an image forming apparatus to which the developer conveying device and the developing device according to the first embodiment of the present invention are applied.

  In FIG. 2, reference numeral 1 denotes a main body of a tandem type full-color printer as an image forming apparatus main body. Inside the printer main body 1, an image forming unit 2 is arranged in a substantially central portion along a vertical direction. It is arranged up and down. Further, inside the full color printer main body 1, a recording medium onto which toner images of a plurality of colors formed by the image forming unit 2 are transferred is adsorbed to one side (right side in the illustrated example) of the image forming unit 2. The control unit 4 having a control circuit and the like is provided on the other side (left side in the illustrated example) of the image forming unit 2. Power supply circuit units 5 each including a high-voltage power supply circuit and the like are disposed obliquely below 2. A paper feeding device 6 for feeding recording paper 37 or the like as a recording medium is disposed at the bottom of the full color printer main body 1.

  The image forming unit 2 includes four process cartridges 7Y, 7M, 7C, and 7K that form toner images of yellow (Y), magenta (M), cyan (C), and black (K) in order from the bottom. These four process cartridges 7Y, 7M, 7C, and 7K are arranged in parallel at regular intervals along the vertical direction.

  These four process cartridges 7Y, 7M, 7C, and 7K are configured in the same manner except for the color of the image to be formed. As shown in FIG. 2, at a predetermined rotational speed along the direction of the arrow. The surface of the photosensitive drum 8 is rotated by a photosensitive drum 8 as an image bearing member that is driven to rotate, a charging roll 9 for primary charging that uniformly charges the surface of the photosensitive drum 8, and an image exposure device 21 described later. An image exposure passage 10 for performing image exposure corresponding to each color to form an electrostatic latent image, and developing means for developing the electrostatic latent image formed on the photosensitive drum 8 with a corresponding color toner. A developing device 11, a cleaning device 12 for cleaning the transfer residual toner remaining on the photosensitive drum 8, and a developer container 13 containing a developer to be supplied to the developing device 11. That.

  In the illustrated embodiment, the developer container 13 is integrally formed with the developing device 11. However, the present invention is not limited to this, and the developer container 13 is separated from the developing device 11. Of course, it may be arranged by.

  As shown in FIG. 2, the image exposure device 21 is configured in common to four process cartridges 7Y, 7M, 7C, and 7K of yellow (Y), magenta (M), cyan (C), and black (K). Four semiconductor lasers 14 that emit laser beams LB based on image data of each color of yellow (Y), magenta (M), cyan (C), and black (K), and the four semiconductor lasers 14 A collimator lens 15 that collimates the four laser beams LB emitted from each other, a reflection mirror 16 that reflects the laser beam LB emitted from the semiconductor laser 14, and a laser beam LB reflected by the reflection mirror 16. The rotary polygon mirror 17 that deflects and scans the laser beam LB reflected by the rotary polygon mirror 17 and the image forming units 7Y, 7M, 7C, and 7K. A plurality of reflecting mirrors 18, 19 for scanning exposure on the photosensitive drum 8, and is configured with a transparent glass 20 that transmits the laser beam LB. The reflection mirrors 18 and 19 have a function of changing the focal length (f) according to the deflection angle (θ) of the laser beam LB.

  On the other hand, as shown in FIG. 2, a control unit 4 is disposed inside the full-color printer main body 1, and the control unit 4 includes, for example, an image for performing predetermined image processing on image data. A processing device 30 is provided. The image processing apparatus 30 sequentially outputs image data of each color of yellow (Y), magenta (M), cyan (C), and black (K) to the image exposure apparatus 10, and the image exposure apparatus 10 outputs the image data. The four laser beams LB emitted according to the above are scanned and exposed on the respective photosensitive drums 8Y, 8M, 8C, and 8K to form electrostatic latent images. The electrostatic latent images formed on the photosensitive drums 8Y, 8M, 8C, and 8K are respectively yellow (Y), magenta (M), cyan (C), and cyan by developing devices 11Y, 11M, 11C, and 11K. The toner image is developed as a black (K) color toner image.

  Further, as shown in FIG. 2, the paper transport belt unit 3 is provided with a paper transport belt 31 that circulates and moves without a break as an endless belt, and the paper transport belt 31 includes each process cartridge 7Y, Recording paper 37 as a recording medium to which toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) formed by 7M, 7C, and 7K are electrostatically adsorbed It is comprised so that it may convey in the state which carried out. The paper transport belt unit 3 is integrally formed with a transport roll 49 provided in a reversing paper transport path 50 (to be described later). When a jam or the like of the recording paper 37 occurs, the printer body By opening the front cover 32, it is possible to move to a retracted position rotated clockwise with respect to the printer body 1.

  As shown in FIG. 2, the sheet conveying belt 31 is stretched between a driving roll 33 and a driven roll 34 as a stretching roll disposed vertically along a vertical direction with a predetermined tension. For example, a drive roll 33 that is rotationally driven through a gear or the like by a drive motor (not shown) is configured to circulate in a clockwise direction at a predetermined speed. For example, the distance between the driving roll 33 and the driven roll 34 is set to be substantially equal to the length of the A3 size recording sheet 37, but is not limited thereto, and the distance between the driving roll 33 and the driven roll 34 is not limited thereto. Of course, it may be set arbitrarily. As the paper transport belt 31, for example, a flexible synthetic resin film such as polyimide is formed in an endless belt shape.

  Further, on the surface of the driven roll 34, as shown in FIG. 2, a suction roll 36 for electrostatically attracting the recording paper 37 to the surface of the paper transport belt 31 is applied via the paper transport belt 31. It arrange | positions so that it may contact | connect. For example, the suction roll 36 is configured by coating the surface of a metal core bar with conductive rubber, similar to the charging roll 9 of the process cartridges 7Y, 7M, 7C, and 7K. A bias voltage for adsorption is applied. The suction roll 36 is configured to electrostatically charge the transfer paper 37 sent from the paper feeding device 6 and suck it onto the surface of the paper transport belt 31.

  Yellow (Y), magenta (M), cyan (C), and black (K) toners formed on the photosensitive drums 8Y, 8M, 8C, and 8K of the process cartridges 7Y, 7M, 7C, and 7K. As shown in FIG. 2, the images are transferred in multiple on the recording paper 37 conveyed while being attracted to the surface of the paper conveying belt 31 while being superimposed on each other by the transfer rolls 38Y, 38M, 38C, and 38K. Is done. The transfer rolls 38Y, 38M, 38C, and 38K are integrally attached to the sheet conveying belt unit 3 side.

  As shown in FIG. 2, the recording sheet 37 is fed from a sheet feeding device 6 disposed at the bottom of the printer body 1. The paper feeding device 6 includes a paper tray 39 that stores recording paper 37 having a desired size and material, and the recording paper 37 having a desired size and material is fed from the paper tray 39 by a feeding roll 40. In addition to being fed, the paper is fed one by one by the supply roll 41 and the separating roll 42, and is conveyed to the suction position on the paper conveyance belt 31 through the registration roll 43 at a predetermined timing. It has become.

  The recording paper 37 is a sheet-like member, for example, various sizes such as A4 size, A3 size, B5 size and B4 size, and thick paper such as plain paper and coated paper, an OHP sheet, etc. Various materials are used.

  Then, as shown in FIG. 2, the recording paper 37 on which the toner images of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are transferred in a multiple manner are recorded on the recording paper 37 itself. After being separated from the paper transport belt 31 by the rigidity (so-called stiffness), it is transported to the fixing device 44, and the toner image of each color is fixed on the recording paper 37 by heat and pressure by the fixing device 44. The paper transport belt 31 and the fixing device 44 are disposed close to each other, and the recording paper 37 separated from the fixing device 44 is transported to the fixing device 44 by the transport force of the paper transport belt 31. Thereafter, the recording paper 37 on which the toner images of the respective colors are fixed is discharged by the discharge roll 45 with the print surface facing down on the discharge tray 46 provided on the upper part of the full-color printer main body 1, and the printing operation is completed. To do.

  The full-color printer is capable of printing not only full-color images but also desired color images such as monochrome, and yellow (Y) and magenta (M) depending on the color of the image to be printed. , Cyan (C), black (K), or some of the process cartridges 7Y, 7M, 7C, and 7K form a toner image.

  Further, when images are formed on both sides of the recording paper 37 by the full-color printer, the recording paper 37 on which the image is fixed on one side by the fixing device 44 is not directly discharged onto the discharge tray 46 by the discharge roll 45. In the state where the trailing edge of the recording paper 37 is held by the discharging roll 45, the discharging roll 45 is reversed, and the transfer path of the recording paper 37 is switched upward by the switching gate 47 so that the recording paper 37 is moved to one side of the printer main body 1. The paper is transported to a reversing paper transport path 50 having a transport roll 49 provided along the transport path. Then, the recording paper 37 conveyed to the reversing paper conveyance path 50 is conveyed again to the suction position of the paper conveyance belt 31 by the registration roll 43 with the front and back sides reversed, and a toner image is formed on the back surface. After the transfer, the fixing device 44 performs a fixing process with heat and pressure, and the paper is discharged onto a discharge tray 46 provided on the upper portion of the printer main body 1 by a discharge roll 45.

  In FIG. 2, reference numeral 51 denotes a paper feed roll for feeding a transfer material of a desired size and material from a manual feed tray (not shown) provided on the side surface of the printer body 1, and 52 denotes a paper feed roll 51. Each of the conveying rolls for conveying the fed recording medium to the registration roll 43 is shown.

  By the way, in this embodiment, as shown in FIG. 3, the yellow (Y), magenta (M), cyan (C), and black (K) process cartridges 7Y, 7M, 7C, and 7K are rotationally driven. An upper first unit 121 having a photosensitive drum 8, a charging roll 9 and a cleaning device 12, a developing device 11 for developing an electrostatic latent image formed on the photosensitive drum 8, and the developing device 11. A lower second unit 122 having a developer container 13 containing a developer to be supplied is formed.

  As shown in FIG. 3, the first unit 121 and the second unit 122 are connected to the photosensitive drum 8 and the developing roll 116 via a fulcrum 123 provided at the end opposite to the photosensitive drum 8. Are connected to each other so as to be swingable in the direction in which they are separated from each other, and are provided at both end portions along the axial direction of the photosensitive drum 8 of the first unit 121 and the developing roll 116 of the second unit 122. The urging means 124 such as a coil spring is urged so as to come into contact with the non-tracking roll.

  The process cartridges 7Y, 7M, 7C, and 7K configured as described above are individually provided by opening a front cover 32 that is openable and closable on the front surface of the printer body 1, as shown in FIG. The process cartridge is configured to be detachable from the printer main body 1. When the photosensitive drum 8 is deteriorated or the developer stored in the developer storage container 13 becomes empty, the process cartridge is used. The user can easily perform maintenance by detaching the printer body 1 every 7Y, 7M, 7C, and 7K and replacing it with new process cartridges 7Y, 7M, 7C, and 7K.

  Further, as shown in FIGS. 4 and 5, the developer storage container 13 of the process cartridges 7Y, 7M, 7C, and 7K has a one-component developer 110 consisting only of toner or a two-component consisting of toner and a carrier. The developer 110 is contained in the developer container 13 and the developer 110 is agitated while the developer 110 is agitated while being in the longitudinal direction of the developer container 13. Two film-shaped agitators 112 are arranged in parallel as developer stirring members for supplying the developer 110 from the developer discharge opening 111 formed at one end. Further, the developer is transferred from the developer container 13 to the developing device 11 between the developer container 13 and the developing device housing 113 of the developing device 11 communicated with the developer discharging opening 111. A developer conveying device 130 for conveying is disposed.

  In this embodiment, the developer storage container 13 stores a one-component developer 110 made of only toner, and the developer storage container 13 is a toner storage container.

  As shown in FIGS. 4 and 5, a stirring auger 114 that rotates the developer 110 supplied into the developing device housing 113 and conveys it in the direction of the arrow is rotatable inside the developing device housing 113. In addition, a supply auger 115 for supplying development to a developing roll 116 as a developer carrying member while agitating and conveying the developer 110 is rotatably arranged in parallel with the agitating auger 114. . Further, the partition wall 117 provided between the stirring auger 114 and the supply auger 115 has a developer at both end portions along the axial direction of the stirring auger 114 and the supply auger 115 as shown in FIG. Passages 118 and 119 for delivering 110 are provided.

  In the developing device 11, as shown in FIGS. 4 and 5, the layer thickness of the developer 110 supplied to the developing roll 116 by the supply auger 115 is regulated to a predetermined value by the layer thickness regulating roll 120. On the other hand, the photosensitive drum 8 is conveyed to a developing area facing the photosensitive drum 8, and the electrostatic latent image formed on the surface of the photosensitive drum 8 is developed with toner of a predetermined color.

  As the developer 110 accommodated in the developing device 11, a two-component developer 110 composed of toner and carrier is used, but a one-component developer composed only of toner may be used. Of course it is good.

  Further, as shown in FIG. 3, the cleaning device 12 removes the transfer residual toner remaining on the surface of the photosensitive drum 8 by the cleaning blade 26, and the removed transfer residual toner is put inside the cleaning device 12. It is comprised so that it may collect | recover and accommodate.

By the way, in this embodiment, a developer transport device that transports the developer from the developer container to the developing device is provided, and the developer transport device contains a developer containing at least a developer containing toner. A developer transport path for transporting the developer from the container to the developing device;
A member disposed in the developer transport path for transporting the developer from the developer container to the developer supply port on the developing device side, in the vicinity of the supply port on the developing device side In addition, the pressing force of the developer transported from the upstream side in the developer transport direction from the supply port on the developing device side without applying a transport force to the developer transported in the developer transport path. And a developer conveying member provided with a developer retaining portion that retains the developer for supplying the developer to the supply port on the developing device side.

  That is, in this embodiment, as shown in FIG. 4, the developer container 13 is provided between the developing device 11 and the developer container 13 integrally disposed on the back side of the developing device 11. Is provided with a developer transport device 130 for transporting the developer 110 to the developing device 11. As shown in FIG. 6, the developer conveying device 130 includes an inside of a developer conveying path 131 in which the developer 110 is formed into a cylindrical tube from the developer discharging opening 111 of the developer containing container 13. Then, the developer 110 sent into the developer transport path 131 is transported by the developer transport member 132 to the front side in FIG. 6 in the longitudinal direction of the developer transport path 131. The developer 110 transported in the developer transport path 131 is configured to be supplied from the developer supply port 133 into the developing device 11 as shown in FIG.

  As shown in FIG. 4, the developer transport path 131 is formed between the developing device 11 and the developer container 13 integrally disposed on the back side of the developing device 11. A developing device housing 113 integrally formed as a bottom surface of the developer container 13, and a developer transport path forming member and a partitioning member 134 provided in a state of being fitted to the upper portion of the developing device housing 113. As described above, it is formed in a cylindrical tubular shape.

  The developer transport path 131 includes a developer discharge opening for discharging the developer 110 from the developer container 13 at one end in the transport direction of the developer transport member 132 on the developer container 13 side. A portion 111 is formed, and one end portion in the transport direction of the transport auger 114 on the developing device 11 side, and on the other end portion on the opposite side to the developer discharge opening 111, A developer supply port 133 that supplies the developer conveyed through the agent conveyance path 131 to the developing device 11 is opened.

  Further, as shown in FIG. 6, the developer discharge opening 111 is opened, for example, in the upper portion of the developer transport path 131, and the developer supply port 133 is formed as shown in FIG. Opened to the side surface or the lower portion of the developer transport path 131.

  On the other hand, as shown in FIG. 8, the developer conveying member 132 is configured by forming conveying blades 136 in a spiral shape at a predetermined pitch on the outer periphery of a rotating shaft 135 formed in a cylindrical shape. The developer 110 discharged from the storage container 13 is transported along the developer (toner) transport direction, and is supplied into the developing device 11 from a supply port 133 located in the vicinity of the downstream end in the developer transport direction. Is. Further, at the end of the developer transport member 132 on the downstream side in the developer transport direction, a return transport blade for transporting the developer 110 transported by the developer transport member 132 to the upstream side in the developer transport direction. 137 is shortly provided in a spiral shape opposite to the conveying blade 136.

  Further, as shown in FIG. 8, the developer transport member 132 is transported to the developer 110 transported in the developer transport path 131 in the vicinity of the developer supply port 134 on the developing device 11 side. A developer retaining portion 138 is provided as a developer dense portion where the developer is denser than the upstream side by retaining without applying force. The developer retaining portion 138 is configured only by the rotation shaft 135 without providing the conveying blade 136 on the outer periphery of the rotation shaft 135. Since the developer retaining portion 138 is composed only of the rotating shaft 135, unlike the portion where the developer blade 136 of the developer conveying member 132 is provided, the developer retaining portion 138 moves downstream in the developer conveying direction with respect to the developer 110. The developer 110 that has moved to the developer retaining portion 138 cannot be applied to the conveying force to be conveyed, and the developer 110 is retained.

  However, since most of the developer transporting member 132 located upstream of the developer retaining part 138 in the developer transporting direction is provided with transporting blades 136, the developer retaining member 138 includes a developer transporting member. The developer 110 is sequentially transported by 132 transport blades 136. As a result, the developer 110 is sequentially transported to the developer retaining part 138 by the transport blades 136 of the developer transporting member 132, and the developer retaining part 138 has a function of transporting the developer 110. Therefore, the developer 110 conveyed to the developer retention part 138 stays and is gradually pressed to be in a predetermined dense state. In the developer retaining portion 138, the developer 110 conveyed to the developer retaining portion 138 is pushed by the pressing force generated when the developer 110 is in a predetermined dense state, and the supply port 134 of the developing device 11. It is gradually conveyed inward and supplied into the developing device 11.

  In the above configuration, in the tandem type full-color multifunction peripheral as an image forming apparatus to which the developing device and the process cartridge according to the first embodiment are applied, the pipe line disposed on the developing device side is as follows. It suppresses the variation in the developer supply amount that occurs when a toner transport member with a toner transport force on the outlet side larger than the toner transport force on the inlet side is used, and supplies a substantially constant amount of developer from the developer container to the developing device. It is possible to suppress variation in the number of developable images with respect to the amount of developer filled in the developer container.

  That is, in the full-color printer according to the first embodiment, as shown in FIG. 2, the yellow (Y), magenta (M), cyan (C), and black (K) process cartridges 7Y, 7M, 7C, and 7K. The toner images of the corresponding colors are formed on the photosensitive drums 8Y, 8M, 8C, and 8K according to the image data, and the toner images of the respective colors formed on the photosensitive drums 8Y, 8M, 8C, and 8K are After being transferred onto the recording paper 37 conveyed while being attracted to the surface of the paper conveying belt 31, it is subjected to a fixing process by the fixing device 44 and provided on the upper portion of the printer main body 1 by the discharge roll 45. It is discharged onto the discharge tray 46.

  At this time, the yellow (Y), magenta (M), cyan (C), and black (K) process cartridges 7Y, 7M, 7C, and 7K are formed on the surfaces of the photosensitive drums 8Y, 8M, 8C, and 8K. When developing the electrostatic latent image, the developer 110 in the developing devices 11Y, 11M, 11C, and 11K is consumed, and the developer containing container 13Y is placed inside the developing devices 11Y, 11M, 11C, and 11K. , 13M, 13C, and 13K, the developer 110 of the corresponding color is transported and supplied by the developer transport device 130.

  In the developer accommodating containers 13Y, 13M, 13C, and 13K, as shown in FIGS. 4 and 5, the developer 110 accommodated in the developer accommodating containers 13Y, 13M, 13C, and 13K includes two films. The developer agitator 112, 112 is agitated, and the developer discharge opening provided at one end of the developer transport path 131 of the developer transport device 130 by the agitator 112 disposed on the developing device 11 side. From 111, the toner is discharged into the developer conveyance path 131.

  The developer 110 discharged into the developer transport path 131 of the developer transport device 130 is transported downstream in the developer transport direction by the developer transport member 132.

  By the way, as shown in FIG. 8, the developer conveying member 132 is conveyed to the developer 110 conveyed in the developer conveying path 131 in the vicinity of the developer supply port 134 on the developing device 11 side. A developer retaining portion 138 that retains without applying force is provided. Therefore, when the developer 110 transported in the developer transport path 131 by the developer transport member 132 moves to the developer retaining portion 138 of the developer transport member 132, as shown in FIG. It stays in the part 138.

  The developer conveying device 130 is driven in synchronism with the start of the image forming operation together with the developing device 11, and the developer in the developing device 11 is consumed before the developing operation is started by the developing device 11. Even in the absence, the developer conveying member 132 of the developer conveying device 130 starts the conveying operation of the developer 110. At this time, since the developer in the developing device 11 is not consumed, the developer 110 is not supplied into the developing device 11 from the developer supply port 133 on the developing device 11 side, as described above. The developer 110 is retained in the developer retaining portion 138 of the developer transport member 132.

  When the developer 110 in the developing device 11 is consumed, the developer is supplied from the developer supply port 133 of the developing device 11, but the developer staying portion 138 of the developer conveying member 132 has a developer. Since the conveying action 110 does not occur, the developer 110 is supplied to the developer supply port 133 of the developing device 11 by the pressing force of the developer.

  More specifically, the developer transport member 132 is provided with transport blades 136 on the upstream side of the developer retainer 138 in the developer transport direction. As shown in (a), the developer 110 is sequentially transported by the transport blades 136 of the developer transport member 132. As a result, the developer 110 is sequentially transported to the developer retaining part 138 by the transport blades 136 of the developer transporting member 132, and the developer retaining part 138 has a function of transporting the developer 110. Therefore, the developer 110 conveyed to the developer retention part 138 stays and is gradually pressed to be in a predetermined dense state. Then, in the developer retaining portion 138, as shown in FIG. 9C, the pressing force F generated when the developer 110 conveyed to the developer retaining portion 138 is in a predetermined dense state. It is pushed, gradually conveyed into the supply port 134 of the developing device 11, and supplied into the developing device 11.

  FIG. 10 shows a modification of the first embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the modification of the first embodiment, FIG. A developer loosening member for loosening the developer retained in the developer retaining portion is provided in the developer retaining portion of the developer conveying member.

  That is, in the modification of the first embodiment of the present invention, as shown in FIG. 10A, the developer staying portion of the developer conveying member is positioned upstream of the developer supply port 111 of the developing device 11. The developer loosening member 150 for loosening the developer staying in the developer staying portion is provided.

  The developer loosening member 150 protrudes toward the outer periphery in the radial direction on the outer periphery of the rotation shaft 135 of the developer transport member 131 and is symmetrical with respect to the plane including the rotation shaft 135 of the developer transport member 131. It is comprised by the two plate-shaped members provided in the state which crossed. The reason why the two plate members constituting the developer loosening member 150 are provided so as to be symmetrical with respect to the plane including the rotation shaft 135 of the developer transport member 131 is that This is to cancel the conveying force with respect to the developer 110 so that the conveying force is not exerted on the developer 110 as a result.

  As the developer loosening member 150, as shown in FIG. 10B, at least one or more (in the illustrated example, toward the outer periphery of the rotating shaft 135 of the developer transport member 131 toward the outer periphery in the radial direction). It may be composed of two or more) protruding plate-like or bar-like members.

  FIG. 10C shows another modification of the first embodiment of the present invention. The developer loosening member 150 is not located upstream of the supply port 111 of the developing device 11 in the developer conveying direction. A part of the developer loosening member 150 is located upstream of the supply port 111 of the developing device 11 in the developer transport direction, and the other most part is opposed to about half of the supply port 111 of the developing device 11. It is arranged.

  In such a case, the developer 110 loosened by the developer loosening member 150 can be directly supplied to the supply port 111 of the developing device 11.

  Next, as shown in FIG. 10 (d), the present inventors provided a conventional developer transport device that does not include the developer retaining portion 138, and a developer retaining portion 138 as illustrated in FIG. A developer conveying device according to the present invention and a developer conveying device according to the present invention provided with a loosening member 150 for loosening the developer in addition to the developer retaining portion 138 as shown in FIG. Experiment to measure the average flow rate and standard deviation (σ) of the amount of developer supplied to the developing device, and the S / N ratio indicating how the amount of supplied developer varies depending on disturbance factors Went.

  As an experimental condition, in the developing device 11 as shown in FIG. 4, 60 g of toner is filled in the developer container 13, and the developer conveying member 132 is set to 0.5 sec in an environment of a temperature of 24 ° C. and a relative humidity of 55%. This was performed by measuring the supply amount (weight mg) of developer to the developing device 11 for 10 seconds by intermittently driving to rotate for 0.5 seconds and intermittently driving to stop for 0.5 seconds.

  FIG. 12 is a chart showing the experimental results.

  As is clear from FIG. 12, the developer fluidity was highest in the conventional developer conveying device, which was 155 mg / 10 sec for the good one and 120 mg / 10 sec for the bad one.

  On the other hand, the developer transport device of the present invention has a lower developer fluidity than the conventional developer transport device, and has a developer retention portion 138 of 140 mg / 10 sec. The bad one was 115 mg / 10 sec, and the one provided with the developer retention portion 138 was 110 mg / 10 sec for the good one and 100 mg / 10 sec for the bad one, but the difference between the two was 25 mg / 10 sec and 10 mg. / 10 sec, which is smaller than the conventional 35 mg / 10 sec.

  The average value and standard deviation of the developer supply amount, and the SN ratio are 138, 24.75, and 14.89 for the conventional one, whereas the developer conveying device of the present invention has 128, 17.68, 17.16 and 105, 7.07, 23.43, particularly in the case of the developer conveying device according to the present invention provided with the loosening member 150 for loosening the developer in addition to the developer retaining portion 138. It can be seen that there is little variation in the flowability of the developer, and the developer can be supplied substantially constant.

FIG. 1 is a block diagram showing a main part of a developing device according to Embodiment 1 of the present invention. FIG. 2 is an overall configuration diagram showing a tandem type full-color multifunction peripheral as an image forming apparatus to which the developing device according to the first embodiment of the present invention is applied. FIG. 3 is a sectional view showing the process cartridge. FIG. 4 is a sectional view showing the developing device. FIG. 5 is a perspective configuration diagram showing the developing device. FIG. 6 is a cross-sectional view showing a main part of the developing device. FIG. 7 is a cross-sectional view showing the main part of the developing device. FIG. 8 is a configuration diagram illustrating the developer conveying member. FIG. 9 is a schematic diagram illustrating a developer conveyance state. FIG. 10 is a block diagram showing a main part of a developing device according to Embodiment 2 of the present invention. FIG. 11 is a configuration diagram illustrating the developer conveying member. FIG. 12 is a chart showing experimental results.

Explanation of symbols

  110: Developer, 130: Developer transport device, 131 Developer transport path, 132: Developer transport member, 133: Developer supply port, 138: Developer retention part (developer dense part).

Claims (6)

A developer transport path for transporting the developer provided in parallel with a stirring auger that transports the developer containing at least toner while stirring ;
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
Without being provided with a transport vane on the outer periphery of the rotation shaft over the region corresponding to the supply port and the region upstream of the supply port in the developer transport direction. Also, the developer is transported toward the supply port by the pressing force of the developer transported from the upstream side in the developer transport direction, so that a developer dense portion where the developer is denser than the upstream side is provided. A provided developer conveying member;
A developer conveying device comprising: The developer conveying member is used for returning the developer conveyed by the developer conveying member to the upstream end in the developer conveying direction at the downstream end of the supply port along the developer conveying direction. The developer conveying device according to claim 1 , further comprising: a conveying blade .   The developer conveying device according to claim 1, wherein a developer loosening member for loosening the developer staying in the developer dense portion is provided in the developer dense portion of the developer conveying member.   The developer conveying device according to claim 3, wherein the developer loosening member is provided upstream of the supply port in the developer conveying direction. A developer container containing a developer containing at least toner;
A developer carrier that develops an electrostatic latent image formed on the image carrier by the developer supplied from the developer container , and a developer that is supplied to the developer carrier is conveyed while stirring. A developing device housing having a stirring auger ;
A developer transport path that is provided in parallel with the stirring auger and transports the developer from the developer container to the developing device housing;
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
A member disposed inside the developer transport path for transporting the developer from the developer container to the developer supply port of the developing device housing and corresponding to the supply port of the developing device housing Development transported from the upstream side in the developer transport direction from the supply port of the developing device housing without providing transport blades on the outer periphery of the rotating shaft over the upstream region in the developer transport direction from the region and the supply port. A developer conveying member provided with a developer dense portion where the developer is denser than the upstream side by conveying the developer toward the supply port by the pressing force of the agent;
A developing device comprising: An image carrier on which an electrostatic latent image corresponding to image information is formed on the surface;
A developer container containing a developer containing at least toner;
A developer carrier that develops an electrostatic latent image formed on the image carrier by the developer supplied from the developer container , and a developer that is supplied to the developer carrier is conveyed while stirring. A developing device housing having a stirring auger;
A developer transport path that is provided in parallel with the stirring auger and transports the developer from the developer container to the developing device housing;
A supply port that opens in a horizontal direction with respect to the stirring auger in the developer transport path, and supplies the developer to the stirring auger;
A member disposed inside the developer transport path for transporting the developer from the developer container to the developer supply port of the developing device housing and corresponding to the supply port of the developing device housing Development transported from the upstream side in the developer transport direction from the supply port of the developing device housing without providing transport blades on the outer periphery of the rotating shaft over the upstream region in the developer transport direction from the region and the supply port. A developer conveying member provided with a developer dense portion where the developer is denser than the upstream side by conveying the developer toward the supply port by the pressing force of the agent;
An image forming apparatus comprising:

Images