JP6772882B2 - Developing equipment and image forming equipment - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine or a printer, and a developing apparatus used for developing an electrostatic latent image formed on an image carrier in such an image forming apparatus. In particular, a developer carrier that holds the developer and conveys it to the image carrier is provided in the main body of the apparatus that houses the developer containing the toner and the carrier, and rotates so as to face the developer carrier. Development that supplies the developer to the developer carrier while rotating the first developer transport member provided with the transport blade member on the outer periphery of the shaft and transporting the developer along the axial direction of the developer carrier. A developer circulation transport unit is provided and a second developer transport member provided with a transport blade member on the outer periphery of the rotating shaft is rotated to transport the developer in the opposite direction to the developer transport and supply unit. The developer transfer and supply section and the developer circulation and transport section are separated by a partition wall provided along the axial direction of the developer carrier, and openings are provided at both ends of the partition wall. In a developing apparatus in which the developing agent is circulated between the developer transporting unit and the developing agent circulation transporting unit through each opening, the developing agent is transferred between the developing agent transporting unit and the developing agent circulating transporting unit. When a new toner is replenished in the main body of the device, the developer can be circulated stably and quickly with the developer transfer unit and the developer circulation without applying a large load to the developer in the main body of the device. It is characterized in that it is quickly circulated with the transport unit so that the replenished toner can be appropriately dispersed in the developing agent in the main body of the apparatus.

Conventionally, in image forming devices such as copiers and printers, toner is supplied from a developing device to an electrostatic latent image formed on an image carrier such as a photoconductor, and the electrostatic latent image formed on the image carrier is provided. I try to develop the image.

Here, in such a developing apparatus, generally, a developing agent containing toner and carriers housed in the main body of the apparatus is held by a developing agent carrier, and the developing agent is used as an image carrier by the developing agent carrier. The toner image in the developer is supplied from the developer carrier to the electrostatic latent image formed on the image carrier to form a toner image.

Then, in such a developing apparatus, generally, the first developing agent conveying member provided with the conveying blade member on the outer periphery of the rotating shaft is rotated so as to face the developing agent carrier provided in the main body of the apparatus. A developer transporting supply unit for transporting the developer along the axial direction of the developer carrier and supplying the developer to the developer carrier is provided, and a transport blade member is provided on the outer periphery of the rotating shaft. A developer circulation transport unit is provided by rotating the second developer transport member to transport the developer in the direction opposite to that of the developer transport supply unit, and the developer transfer supply unit and the developer circulation transport unit are provided. The developer is separated by a partition wall provided along the axial direction of the developer carrier, and openings are provided at both ends of the partition wall, and the developer is transferred to the developer transport supply unit and the developer circulation through each opening. It is made to circulate with the transport unit.

Further, in such a developing apparatus, when the toner in the developer is supplied from the developer carrier to the electrostatic latent image formed on the image carrier to form the toner image as described above, the development in the apparatus main body is performed. Since the toner in the agent gradually decreases and the toner concentration decreases, and a sufficient image density cannot be obtained, the toner is generally replenished in the developing agent contained in the main body of the apparatus.

Here, when the toner is replenished in the developer housed in the apparatus main body in this way, only the amount of toner in the developer in the portion where the toner is replenished rises and enters the apparatus main body. There is a large difference in the toner concentration in the contained developer, causing uneven density in the formed image, or the replenished toner is used for development in a state where it is not sufficiently charged, and the formed image is fogged. There is a problem that the toner is scattered or the toner is scattered.

Conventionally, a developer provided in the developer transport supply unit or the developer circulation transport unit is provided so that the developer to which the toner is replenished is quickly transported and mixed with another developer. The rotation speed of the transport member has been increased, and fins have been attached to the developer transport member.

However, even in such a case, it is still difficult to quickly eliminate the unevenness of the toner concentration in the developer, and if the rotation speed of each developer transport member is made too high, the developer deteriorates. There was a problem such as

Further, conventionally, as shown in Patent Document 1, the developer is transferred between the developer transporting unit and the developing agent circulating transporting unit through the openings provided at the ends on both sides of the partition wall as described above. In the middle of the openings on both sides of the partition wall, an intermediate opening for moving the developer between the developer transport supply unit and the developer circulation transport unit is provided, and the intermediate opening is provided. Fins having a height extending from the rotation axis to the outer periphery of the transport blade member are provided for each of the above-mentioned developer transport members at the position of the unit, and each developer transport member is rotated to transport and supply the developer. It has been proposed that the developer transported in the axial direction in the section and the developer circulation transport section is moved between the developer transport supply section and the developer circulation transport section through the intermediate opening by the fins. ing.

However, in Patent Document 1, as described above, fins having a height extending from the rotation axis to the outer periphery of the transport blade member in the radial direction are provided for each developer transport member at the position of the intermediate opening. Therefore, at the position of the intermediate opening, a large amount of the developer is fed in the direction intersecting the axial direction by the fins in each developer transport member, and the developer is transported in the axial direction by each developer transport member. There is a problem that the amount is reduced and the developer cannot be efficiently circulated between the developer transporting unit and the developing agent circulating and transporting unit.

JP-A-2007-316130

An object of the present invention is to solve the above-mentioned problems in a developing device used for developing an electrostatic latent image formed on an image carrier in an image forming device such as a copying machine or a printer. Is.

That is, in the present invention, a developer carrier that holds the developer and conveys it to the image carrier is provided in the main body of the apparatus that houses the developer containing the toner and the carrier, and faces the developer carrier. In this way, the first developer transport member provided with the transport blade member on the outer periphery of the rotating shaft is rotated, and the developer is carried while the developer is transported along the axial direction of the developer carrier. A developer transporting and supplying unit for supplying to the body is provided, and a second developing agent transporting member provided with a transporting blade member on the outer periphery of the rotating shaft is rotated to transport the developing agent in the direction opposite to that of the developing agent transporting and supplying unit. A developer circulation transport section is provided, and the developer transport supply section and the developer circulation transport section are separated by a partition wall provided along the axial direction of the developer carrier, and at both ends of the partition wall. In a developing apparatus in which openings are provided and the developer is circulated between the developer transport supply unit and the developer circulation transport unit through each opening, the developer is circulated between the developer transport supply unit and the developer circulation unit. When a new toner is replenished in the main body of the apparatus, the developer is conveyed and supplied without imposing a large load on the developer in the main body of the apparatus. An object of the present invention is to promptly circulate between the unit and the developing agent circulation transport unit so that the replenished toner can be appropriately dispersed in the developing agent in the main body of the apparatus.

In the developing apparatus of the present invention, in order to solve the above-mentioned problems, a developing agent carrier that holds the developing agent in the main body of the apparatus containing the developing agent containing toner and carriers and conveys the developing agent to the image carrier. The first developer transport member provided with the transport blade member on the outer periphery of the rotating shaft is rotated so as to face the developer carrier, and the developer is transferred in the axial direction of the developer carrier. A developer transporting and supplying unit that supplies the developing agent to the developing agent carrier while transporting along the line is provided, and a second developing agent transporting member provided with a transporting blade member on the outer periphery of the rotating shaft is rotated to transfer the developing agent. A developer circulation transport section for transporting the developer in the opposite direction to the developer transport supply section is provided, and the developer transport supply section and the developer circulation transport section are separated by a partition wall provided along the axial direction of the developer carrier. At the end of the partition wall separated, a first opening for guiding the developer from the developer transport supply unit to the developer circulation transport unit and a developer are transferred from the developer circulation transport unit to the developer circulation transport unit. In a developing apparatus in which a second opening for guiding is provided and the developing agent is circulated between the developing agent transporting unit and the developing agent circulating transporting unit through each opening.
An intermediate opening for moving the developer between the developer transport supply unit and the developer circulation transport unit in the middle portion between the first opening and the second opening at the end of the partition wall. And increased the diameter of the rotating shaft at at least one of the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening.

Here, as in the developing apparatus of the present invention, the developing agent is transferred to the developing agent transporting unit and the developing agent circulating transporting portion in the middle between the first and second openings at both end portions of the partition wall. An intermediate opening to be moved between the parts is provided, and the diameter of the rotating shaft at at least one of the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening is increased. In the parts of the first developer transfer member and the second developer transfer member in which the diameter of the rotating shaft is increased, the developer in the developer transfer supply unit and the developer circulation transfer unit is pushed, and the developer transfer supply unit and development are performed. The developer in the agent circulation transfer unit is sent to the developing agent circulation transfer unit and the developer transfer supply unit facing each other through the intermediate opening. Then, the developer sent to the developer circulation transport section and the developer transport supply section facing each other through the intermediate opening in this way is provided in the developer circulation transport section and the developer transport supply section. It is transported by the transport member and circulated between the developer circulation transport unit and the developer transport and supply unit.

Further, in the developing apparatus of the present invention, it is preferable to increase the diameter of the rotating shafts of both the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening. In this way, in the portion of the first developer transport member and the second developer transport member in which the diameter of the rotating shaft is increased as described above, the developer in the developer transport supply unit and the developer circulation transport unit Is pressed, and the developer in the developer transport unit and the developer circulation transport unit is sent to the developer circulation transport unit and the developer transfer supply unit facing each other through the intermediate opening, respectively, and the developer transfer supply unit and the developing agent are developed. The developer in the agent circulation transport section is stably circulated between the developer transport supply section and the developer circulation transport section through the intermediate opening.

Here, in the developing apparatus of the present invention, in providing a portion having a large diameter on both the rotating shafts of the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening, the first developing agent is provided. It is preferable that the portion having the maximum diameter of the rotating shaft in the transport member and the portion having the maximum diameter of the rotating shaft in the second developer transport member do not face each other. In this way, the developer pressed by the maximum diameter portion of the rotating shaft in the first developer transport member and the developer pressed by the maximum diameter portion of the rotating shaft in the second developer transport member are intermediate. Collision at the position of the opening prevents the developer feeds from interfering with each other.

Further, as described above, when the portion having the maximum diameter of the rotating shaft in the first developer conveying member and the portion having the maximum diameter of the rotating shaft in the second developing agent conveying member are provided so as not to face each other, the first developer is provided. The maximum diameter portion of the rotating shaft in the transport member and the maximum diameter portion of the rotating shaft in the second developer transport member, or the maximum diameter portion of the rotating shaft in the other developing agent transport member facing each other through the intermediate opening. It is preferable to provide the developer at a position on the upstream side in the transport direction of the developer by each developer transport member, rather than at the position of. In this way, the developer sent by the portion having the maximum diameter of the rotating shaft in the first developer conveying member and the developer sent by the portion having the maximum diameter of the rotating shaft in the second developer conveying member overlap. It is prevented from being transported without any trouble, and the transport of the developer by each developer transport member is hindered from each other.

Further, when a portion having a large diameter is provided on the rotation shafts of both the first developer transfer member and the second developer transfer member at the position of the intermediate opening as described above, the rotation of the first developer transfer member The portion where the diameter of the shaft is increased and the portion where the diameter of the rotating shaft of the second developer conveying member is increased can be partially overlapped at positions facing each other via the intermediate opening. preferable. In this way, a part of the developer sent to the other developer transport member through the intermediate opening by the portion where the diameter of the rotating shaft in each developer transport member is increased is intermediated by the other developer transport member. It is possible to prevent a bias in the amount of the developer that is returned through the opening and is conveyed and circulated between the developer transport supply unit and the developer circulation transport unit.

Further, when a portion having a large diameter of the rotating shaft in the first developing agent conveying member and the second developing agent conveying member is provided, the length of the portion having a large diameter of the rotating shaft is the length of the intermediate opening. Try to be shorter than the length. This is because when the length of the portion where the diameter of the rotating shaft is increased is longer than that of the intermediate opening, the developing agent sent outward in the radial direction at the portion where the diameter of the rotating shaft is increased is generated by the intermediate opening. This is because the developer is agglomerated by being pressed against the non-existent partition wall.

Further, when a portion having a large diameter is provided on the rotating shaft of the first developer conveying member and the second developing agent conveying member as described above, the area of the conveying blade member provided on the rotating shaft is reduced, and the developer is developed. Since the ability to convey the shaft in the axial direction is reduced, the pitch and number of threads of the transport blade member provided on the rotating shaft portion having an increased diameter are changed, and the transport blade member on the rotating shaft portion having an increased diameter is used. , It is preferable that the developer is appropriately conveyed in the axial direction.

Further, in the developing apparatus of the present invention, when the first developer conveying member and the second developing agent conveying member are provided with a portion having a large diameter of the rotating shaft as described above, the developing agent is conveyed from the upstream side to the downstream side. It is preferable to form the rotating shaft in a tapered shape up to the portion where the diameter of the rotating shaft becomes the maximum diameter so as to continuously increase to the portion where the diameter of the rotating shaft becomes the maximum diameter toward the side. This is because when the diameter of the rotating shaft is rapidly increased, the developer that has been conveyed is suppressed at the portion where the diameter is rapidly increased, and it becomes difficult to appropriately convey the developer in the axial direction. Because.

Further, in the developing apparatus of the present invention, the diameter of the rotating shaft becomes the maximum diameter when the first developer conveying member and the second developing agent conveying member are provided with a portion having a large diameter of the rotating shaft as described above. It is preferable that the condition of α> β is satisfied when the distance to α is defined as α and the distance from the portion having the maximum diameter to the original constant diameter of the rotating shaft is β. In this way, after the developer is sent to the opposite side through the intermediate opening at the portion where the diameter of the rotating shaft becomes the maximum diameter, the remaining developer is promptly released to the shaft by each developer transport member. It will be transported in the direction.

Further, with the developing apparatus of the present invention set, the angle formed by the horizontal line and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is ω, the intermediate. When the maximum diameter of the rotating shaft of the second developer conveying member at the opening is φ1 and the maximum diameter of the rotating shaft of the first developing agent conveying member is φ2,
When the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is horizontal (ω = 0 °), the condition of (φ1 / φ2) = 1 is satisfied.
The first developer transfer member is located diagonally above the second developer transfer member, and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is relative to the horizontal line. When it is tilted counterclockwise (90 °>ω> 0 °), the condition of (φ1 / φ2)> 1 is satisfied.
The first developer transport member is located diagonally below the second developer transport member, and the line connecting the rotation center of the second developer transport member and the rotation center of the first developer transport member is relative to the horizontal line. When it is tilted clockwise (0 °>ω> −90 °), it is preferable to satisfy the condition of (φ1 / φ2) <1. In this way, even if the vertical positional relationship between the first developer transport member and the second developer transport member changes and the developer is affected by gravity at the position of the intermediate opening, the intermediate opening At the position of the unit, the amount of the developer transferred between the developer transport unit and the developer circulation transport unit can be appropriately maintained.

Further, with the developing apparatus of the present invention set, the angle formed by the horizontal line and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is ω, the intermediate. The height of the intermediate opening in the portion where the diameter of the rotating shaft of the second developer transport member is the maximum diameter is L1, and the intermediate opening in the portion where the diameter of the rotating shaft of the first developer transport member is the maximum diameter. When the height of the part is L2,
When the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is horizontal (ω = 0 °), the condition of (L1 / L2) = 1 is satisfied.
The first developer transfer member is located diagonally above the second developer transfer member, and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is relative to the horizontal line. When it is tilted counterclockwise (90 °>ω> 0 °), the condition of (L1 / L2)> 1 is satisfied.
The first developer transport member is located diagonally below the second developer transport member, and the line connecting the rotation center of the second developer transport member and the rotation center of the first developer transport member is relative to the horizontal line. When it is tilted clockwise (0 °>ω> −90 °), it is preferable to satisfy the condition of (L1 / L2) <1. In this way, even if the vertical positional relationship between the first developer transport member and the second developer transport member changes and the developer is affected by gravity at the position of the intermediate opening, the intermediate opening At the position of the unit, the amount of the developer transferred between the developer transport unit and the developer circulation transport unit can be appropriately maintained.

Then, in the image forming apparatus of the present invention, the developing apparatus as described above is used.

In the developing apparatus of the present invention, as described above, the developing agent is transferred to the developing agent transporting unit and the developing agent circulating transporting portion in the middle between the first and second openings at both end portions of the partition wall. An intermediate opening to be moved between the parts is provided, and the diameter of the rotating shaft at at least one of the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening is increased. In the parts of the first developer transfer member and the second developer transfer member in which the diameter of the rotating shaft is increased, the developer in the developer transfer supply unit and the developer circulation transfer unit is pushed, and the developer transfer supply unit and development are performed. The developer in the agent circulation transport section is sent to the facing developer circulation transport section and the developer transport section through the intermediate opening, and thus the developer circulation transport section and the developer transport supply section facing each other through the intermediate opening. The developer sent to the unit is conveyed by each of the above-mentioned developer transfer members provided in the developer circulation transfer unit and the developer transfer and supply unit, and is connected to the developer circulation and transfer unit and the developer transfer and supply unit. It will be properly circulated between the three openings.

As a result, in the developing apparatus of the present invention, even when new toner is replenished in the apparatus main body, the developing agent is conveyed through the three openings without applying a large load to the developing agent in the apparatus main body. The supplied toner can be appropriately dispersed in the developing agent in the main body of the apparatus while being rapidly circulated between the supply unit and the developing agent circulation transport unit.

FIG. 5 is a schematic explanatory view of an image forming apparatus using a plurality of developing apparatus in one embodiment of the present invention. It is schematic explanatory drawing which showed the state which looked at the inside of the developing apparatus which concerns on embodiment of this invention from above. Inside the developing apparatus according to the above embodiment, (A) is a schematic explanatory view of a side surface side in a portion where the partition wall is not provided with an opening, and (B) is a side surface in a portion where an intermediate opening is provided in the partition wall. It is a schematic explanatory view of the side. In the developing apparatus according to the above-described embodiment, the angle ω formed by the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member and the horizontal line is 0 °, and the second development It is a schematic explanatory view of the side surface side which showed the state which the maximum diameter φ1 in the rotation shaft of the agent transport member and the maximum diameter φ2 in the rotation shaft of the first developer transport member are the same diameter (φ1 = φ2). In the developing apparatus according to the above embodiment, the inside of the first modification in which the first developer transporting member and the second developer transporting member provided in the developer transporting unit and the developing agent circulating transporting unit are changed is shown above. It is a schematic explanatory drawing which showed the state seen from. It is a schematic partial explanatory view which showed the state of the 1st developer transfer member and the 2nd developer transfer member in the part provided with the intermediate opening in the said 1st modification. In the developing apparatus according to the above-described embodiment, the first developer transport member is located diagonally above the second developer transport member, and the rotation center of the second developer transport member and the rotation center of the first developer transport member When the angle ω in which the line connecting the two members is inclined counterclockwise with respect to the horizontal line is 90 °> ω> 0 °, the maximum diameter φ1 of the rotation axis of the second developer transfer member is set to the first developer transfer member. It is a schematic explanatory view of the side surface side which showed the 2nd modification example which made it larger than the maximum diameter φ2 of the rotating shaft of. In the developing apparatus according to the above-described embodiment, the first developer transport member is located diagonally above the second developer transport member, and the rotation center of the second developer transport member and the rotation center of the first developer transport member An intermediate opening in a portion where the diameter of the rotating shaft of the second developer transport member becomes the maximum diameter when the angle ω in which the line connecting the two is inclined counterclockwise with respect to the horizontal line is 90 °> ω> 0 °. In the schematic explanatory view of the intermediate opening showing a third modification example in which the height L1 of the above is made larger than the height L2 of the intermediate opening in the portion where the diameter of the rotating shaft of the first developer conveying member becomes the maximum diameter. is there.

Next, the developing apparatus and the image forming apparatus according to the embodiment of the present invention will be specifically described with reference to the accompanying drawings. The developing apparatus and the image forming apparatus according to the present invention are not limited to those shown in the following embodiments, and can be appropriately modified and implemented without changing the gist thereof.

In the image forming apparatus 1 of this embodiment, as shown in FIG. 1, four photoconductors 10 are provided inside the image forming apparatus 1, and a developing agent containing toner and a carrier is accommodated in each photoconductor 10. Four developing devices 30 are provided, and in each developing device 30, the color of the toner in each developing agent is different, and black, yellow, magenta, and cyan toners are used.

Then, in the image forming apparatus 1, each of the photoconductors 10 is rotated to charge the surface of each photoconductor 10 by the charging device 11, and the surface of each photoconductor 10 thus charged is charged. Each of the latent image forming devices 12 performs exposure according to the image forming information, and an electrostatic latent image according to the image forming information is formed on the surface of each photoconductor 10.

Next, each photoconductor 10 on which the electrostatic latent image is formed is developed by supplying toner of a predetermined color from the corresponding developing device 30 to the electrostatic latent image of each photoconductor 10. , Toner images of each color are formed on the surface of each photoconductor 10.

Then, the toner images of the respective colors formed on the photoconductors 10 as described above are spread over the rotating roller 13 and rotationally driven on the surface of the endless intermediate transfer belt 14, and the photoconductors 10 are described above. The primary transfer is sequentially performed by each of the primary transfer rollers 15 provided so as to face the intermediate transfer belt 14, and a toner image in which toner images of each color are combined is formed on the surface of the intermediate transfer belt 14. Further, the toner and the like remaining on the surface of each photoconductor 10 without being transferred to the intermediate transfer belt 14 are removed from the surface of each photoconductor 10 by the first cleaning device 16, respectively. ..

Then, the toner image formed on the intermediate transfer belt 14 as described above is guided by the intermediate transfer belt 14 to a position facing the secondary transfer roller 17.

On the other hand, the paper S housed in the lower part of the image forming apparatus 1 is fed by the paper feed roller 18 and sent to the timing roller 19, and the paper S is fed by the timing roller 19 at an appropriate timing with the intermediate transfer belt 14 and secondary. It is guided between the transfer roller 17 and the toner image formed on the intermediate transfer belt 14 is transferred to the paper S by the secondary transfer roller 17. Further, the toner remaining on the intermediate transfer belt 14 without being transferred to the paper S is collected from the intermediate transfer belt 14 by the second cleaning device 20.

Then, the paper S on which the toner image is transferred is guided to the fixing device 21 as described above, and the transferred toner image is fixed on the paper S by the fixing device 21, and then the toner image is fixed in this way. The paper S is discharged by the paper ejection roller 22.

The image forming apparatus 1 is not limited to the above, and although not shown, the rotary developing apparatus holding a plurality of developing apparatus is rotated, and each developing apparatus is sequentially formed into a photoconductor. A full-color image forming apparatus for forming a full-color image by guiding the image, or an image forming apparatus for forming a black-and-white image may be used.

Next, the developing device 30 according to the embodiment of the present invention will be specifically described.

In the developing apparatus 30, as shown in FIGS. 2 and 3 (A) and 3 (B), the developing agent D containing the toner and the carrier is housed in the apparatus main body 31, and a magnet roller 32a is provided inside. The cylindrical developer carrier 32 is provided so as to face the photoconductor 10 with a required interval.

Then, in the apparatus main body 31, as shown in FIGS. 2 and 3 (A) and 3 (B), the developer D is conveyed along the axial direction of the developer carrier 32, and the developer D is conveyed. A screw-shaped transport blade member that is provided with a developer transport and supply unit 33 that supplies D to the developer carrier 32, and conveys the developer D around the rotating shaft 34a while stirring in the developer transport and supply unit 33. A first developer transport member 34 provided with 34b is provided.

Further, the developer circulation transport unit 36 that transports the developer transport supply unit 33 and the developer D in opposite directions to a position away from the developer carrier 32 via the developer transport supply unit 33 and the partition wall 35. A second developer transport member 37 provided with a screw-shaped transport blade member 37b for transporting the developer D around the rotating shaft 37a while stirring is provided in the developer circulation transport unit 36. ..

Then, the developer D is applied to both ends of the partition wall 35 provided between the developer transfer and supply unit 33 and the developer circulation and supply unit 36 from the developer transfer and supply unit 33 to the developer circulation and transfer unit 36. A first opening 35a for guiding the developer D to the developer and a second opening 35b for guiding the developer D from the developer circulation transport unit 36 to the developer transport supply unit 33 are provided, and development is performed through these openings 35a and 35b. The agent D is circulated between the developer transport and supply unit 33 and the developer circulation and transport unit 36.

Further, in the developing apparatus 30 of this embodiment, the developing agent D is added to the developing agent D in the middle portion between the first and second openings 35a and 35b at both end portions of the partition wall 35. An intermediate opening 35c is provided to move between the transport supply unit 33 and the developer circulation transport unit 36, and the height of the intermediate opening 35c is kept constant.

Here, in the rotary shaft 34a of the first developer transport member 34, the shaft diameter is on the upstream side in the transport direction of the developer D at the position of the intermediate opening 35c, and the shaft diameter is on the downstream side in the transport direction of the developer D. A large diameter portion 34a1 that is continuously increased in a tapered shape until the maximum diameter becomes φ2 is provided, and the rotating shaft 37a of the second developer conveying member 37 is also developed at the position of the intermediate opening 35c. A large diameter portion 37a1 whose shaft diameter is continuously increased in a tapered shape toward the downstream side in the transport direction of the developer D until the maximum diameter becomes φ1 is provided in the portion on the upstream side in the transport direction of the agent D.

Then, the portion having the maximum diameter φ2 of the large diameter portion 34a1 on the rotating shaft 34a of the first developing agent conveying member 34 and the portion having the maximum diameter φ1 of the large diameter portion 37a1 on the rotating shaft 37a of the second developing agent conveying member 37. Is provided so that they do not face each other. Further, the number of rows of the transport blade member 34b in the portion of the large diameter portion 34a1 of the rotary shaft 34a of the first developer transport member 34 is made larger than that of other portions in the rotary shaft 34a of the first developer transport member 34. At the same time, the number of rows of the transport blade member 37b in the portion of the large diameter portion 37a1 of the rotary shaft 37a of the second developer transport member 37 is larger than that of the other portions in the rotary shaft 37a of the second developer transport member 37. ..

Further, in the developing apparatus 30 of this embodiment, as shown in FIG. 4, a line connecting the rotation center of the second developer transport member 37 and the rotation center of the first developer transport member 34 and a horizontal line are formed. The forming angle ω is set to 0 °, and the maximum diameter φ1 on the rotating shaft 37a of the second developing agent conveying member 37 and the maximum diameter φ2 on the rotating shaft 34a of the first developing agent conveying member 34 are the same diameter (φ1 = It is designed to be φ2).

Here, as described above, the portion having the maximum diameter φ2 of the large diameter portion 34a1 on the rotating shaft 34a of the first developing agent conveying member 34 and the maximum diameter of the large diameter portion 37a1 on the rotating shaft 37a of the second developing agent conveying member 37. When the φ1 portion is provided so as not to face each other, the developer is provided from the developer transport supply portion 33 through the intermediate opening 35c by the portion having the maximum diameter φ2 of the large diameter portion 34a1 on the rotating shaft 34a of the first developer transport member 34. The developer D sent to the circulating transport unit 36 and the portion of the rotating shaft 37a of the second developer transport member 37 having the maximum diameter φ1 of the large diameter portion 37a1 convey the developer from the developer circulating transport unit 36 through the intermediate opening 35c. The developer D is prevented from colliding with the developer D sent to the supply unit 33, the feed of the developer D is not hindered from each other, and the developer D is transferred to the developer transfer supply unit 33 through the intermediate opening 35c. It becomes possible to appropriately move the developer to and from the developing agent circulation transport unit 36.

Further, as described above, the number of rows of the transport blade member 34b in the portion of the large diameter portion 34a1 of the rotary shaft 34a of the first developer transport member 34 is larger than that of other portions in the rotary shaft 34a of the first developer transport member 34. In addition to increasing the number of lines of the transport blade member 37b in the portion of the large diameter portion 37a1 of the rotary shaft 37a of the second developer transport member 37, the number of rows of the transport blade member 37b is larger than that of other portions in the rotary shaft 37a of the second developer transport member 37. As described above, the developer D conveys the developer through the intermediate opening 35c in the large-diameter portion 34a1 of the first developer transport member 34 and the large-diameter portion 37a1 of the rotating shaft 37a of the second developer transport member 37. Even if it is sent between the supply unit 33 and the developer circulation transfer unit 36, the first developer transfer member 34 and the second developer transfer member 37 in which the number of lines of the transfer blade members 34b and 37b are increased in this way. As a result, an appropriate amount of the developer D is sufficiently conveyed along the developer transport supply unit 33 and the developer circulation transport unit 36 even in the intermediate opening 35c.

Further, in the developing apparatus 30 of this embodiment, the developing agent D is guided from the developer transporting and supplying unit 33 through the first opening 35a to the developing agent circulation transporting unit 36 on the upstream side in the transporting direction of the developing agent D. A toner replenishment port 41 for replenishing new toner from the toner replenishment device 40 is provided in the portion, and the toner replenished from the toner replenishment port 41 is combined with the developing agent D in the developing agent circulation transport unit 36 and described above. The developer is conveyed by the developer conveying member 37.

Here, in the developing apparatus 30 of this embodiment, the developing agent D in the apparatus main body 31 passes through the first and second openings 35a and 35b at both ends of the partition wall 35 to carry and supply the developing agent 33. Not only is the part of the developer D circulated between the developer and the developer circulation transport unit 36, but a part of the developer D is passed through the first opening 35a and the intermediate opening 35c to the upstream portion of the developer circulation transport unit 36. And the downstream portion of the developer circulation transport unit 33, and further, through the second opening 35b and the intermediate opening 35c, the downstream portion of the developer circulation transport unit 36 and the developer transfer It will be circulated with the upstream portion of the supply unit 33.

Therefore, when new toner is replenished from the toner replenishment port 41 to the portion of the developer circulation transport unit 36 on the upstream side in the transport direction of the developer D as described above, development in which the new toner is replenished in this way. The agent D is circulated in the apparatus main body 31 through the above three routes, and the replenished toner is rapidly dispersed in the developing agent D in the apparatus main body 31, and the transport blade member 34b, as described above. Due to the first developer transport member 34 and the second developer transport member 37 having an increased number of 37b strips, an appropriate amount of the developer D is added to the developer transport supply unit 33 and the developer even in the intermediate opening 35c. Sufficiently transported along the circulation transport section 36, a large load is applied to the developer D transported by the first developer transport member 34 and the second developer transport member 37, or each developer is transported. It is also possible to prevent the torque applied to the transport members 34 and 37 from increasing.

In the developing apparatus 30 of the above embodiment, as described above, the large diameter portion 34a1 of the rotating shaft 34a of the first developing agent conveying member 34 is formed so as to be tapered to a portion having a maximum diameter of φ2. , The large diameter portion 37a1 of the rotating shaft 37a of the second developer transport member 37 is formed so as to be tapered to the portion having the maximum diameter φ1, and the large diameter portion 34a1 of the first developer transport member 34 is formed to have a maximum diameter of φ2. The large diameter portion 37a1 of the second developer transport member 37, which is the portion of the above, is provided so as not to face the portion having the maximum diameter φ1. However, the large diameter portion 34a1 on the rotating shaft 34a of the first developer conveying member 34 and the large diameter portion 37a1 on the rotating shaft 37a of the second developing agent conveying member 37 are not limited to such.

For example, as shown in FIGS. 5 and 6, the large diameter portion 34a1 of the rotating shaft 34a of the first developer transport member 34 is formed so as to be tapered to a portion having a maximum diameter of φ2, and further having a maximum diameter of φ2. Along with contracting in a tapered shape from the portion toward the downstream side, the large diameter portion 37a1 of the rotating shaft 37a of the second developer conveying member 37 is formed so as to taper up to a portion having a maximum diameter of φ1, and further, the maximum diameter is further expanded. A large diameter portion 34a1 and a portion having a maximum diameter of φ1 on the rotating shaft 34a of the first developer transport member 34, which is contracted in a tapered shape from the portion of φ1 toward the downstream side and thus contracted from the portion having a maximum diameter of φ2. It is also possible to make a part of the rotating shaft 37a of the second developer transporting member 37 contracted from the above with the large diameter portion 37a1 overlap. In this way, the developer D sent to the other through the intermediate opening 35c by the tapered large diameter portions 34a1 and 37a1 of the rotating shafts 34a and 37a in the developer conveying members 34 and 37. A part of the above is returned through the intermediate opening 35c at the portion that is tapered toward the downstream side as described above, and is conveyed and circulated in the developer transport supply unit 33 and the developer circulation transport unit 36. It is possible to prevent the amount of the developer D from being biased.

Further, in this embodiment, when the first developer transporting member 34 and the second developer transporting member 37 are provided with the above-mentioned large diameter portions 34a1 and 37a1 as shown in FIGS. 5 and 6. The distance until the diameters of the rotating shafts 34a and 37a are tapered to reach the maximum diameters of φ2 and φ1 is α, and the diameters of the rotating shafts 34a and 37a are tapered from the portions where the maximum diameters are φ2 and φ1. When β is the distance from contraction to the original constant diameter, the condition of α> β is satisfied. In this way, after the developer D is sent to the opposite side through the intermediate opening 35c at the portion where the diameters of the rotating shafts 34a and 37a are the maximum diameters φ2 and φ1, the remaining developer D However, each of the developer transport members 34 and 37 quickly transports the developer in the axial direction.

Further, in the developing apparatus 30 according to the above-described embodiment, as shown in FIG. The angle ω formed by the line connecting the center of rotation of the first developer transport member 34 and the horizontal line is set to 0 °, but the developer transport supply unit 33 and the developer circulation transport unit 36 are provided at an angle. The line connecting the center of rotation of the second developer transfer member 37 and the center of rotation of the first developer transfer member 34 may be inclined with respect to the horizontal line.

For example, as shown in FIG. 7, the developer transporting unit 33 is provided diagonally above the developer circulation transporting unit 36, and the first developing agent transporting member 34 is located diagonally above the second developing agent transporting member 37. Then, the angle ω at which the line connecting the rotation center of the second developer transfer member 37 and the rotation center of the first developer transfer member 34 is inclined counterclockwise with respect to the horizontal line becomes 90 °> ω> 0 °. Can be.

Then, the angle ω at which the line connecting the center of rotation of the second developer transfer member 37 and the center of rotation of the first developer transfer member 34 is inclined counterclockwise with respect to the horizontal line is 90 °> ω> 0. When the temperature is adjusted to °, as shown in FIG. 7, the maximum diameter φ1 of the large-diameter portion 37a1 in the second developer transport member 37 provided in the developer circulation transport unit 36 is changed to the developer transport unit 33. [(Φ1 / φ2)> 1], which is larger than the maximum diameter φ2 of the large diameter portion 34a1 of the first developing agent transporting member 34 provided in the above, and the large diameter portion 37a1 of the second developing agent transporting member 37 located on the lower side. The amount of developer D sent from the intermediate opening 35c to the first developer transport member 34 and the second developer transfer from the large diameter portion 34a1 of the first developer transport member 34 located on the upper side through the intermediate opening 35c. The amount of developer D sent to member 34 can be made to correspond.

Further, as described above, the angle ω at which the line connecting the center of rotation of the second developer transport member 37 and the center of rotation of the first developer transport member 34 is inclined counterclockwise with respect to the horizontal line is 90 °> ω>. When the temperature is set to 0 °, the maximum diameter φ1 of the large diameter portion 37a1 of the second developer transport member 37 provided in the developer circulation transport unit 36 and the developer transport supply unit 33 are provided. As shown in FIG. 8, the maximum diameter 37a1 of the second developer transport member 37 is located on the lower side without changing the maximum diameter φ2 of the large diameter portion 34a1 of the first developer transport member 34. The height L1 of the intermediate opening 35c at the position corresponding to the portion having the diameter φ1 is set to the height L1 of the intermediate opening 35c at the position corresponding to the portion having the maximum diameter φ2 of the large diameter portion 34a1 in the first developing agent transport member 34 located on the upper side. Of the developer D, which is made larger than the height L2 and is sent from the large diameter portion 37a1 of the second developer transport member 37 located on the lower side to the first developer transport member 34 through the intermediate opening 35c of the height L1. The amount is made to correspond with the amount of the developer D sent from the large diameter portion 34a1 of the first developer transport member 34 located on the upper side to the second developer transport member 34 through the intermediate opening 35c of the height L2. can do.

Although not shown, contrary to the cases of FIGS. 7 and 8, the developer transport supply unit 33 is provided diagonally below the developer circulation transport unit 36, and the first developer transport member 34 is the first. 2 Located diagonally below the developer transport member 37, the line connecting the center of rotation of the second developer transport member 37 and the center of rotation of the first developer transport member 34 is inclined clockwise with respect to the horizontal line. When the angle ω inclined counterclockwise is 0 °> ω> −90 °, the opposite of the case of FIGS. 7 and 8 is set.

1: Image forming device 10: Photoconductor 11: Charging device 12: Latent image forming device 13: Rotating roller 14: Intermediate transfer belt 15: Primary transfer roller 16: First cleaning device 17: Secondary transfer roller 18: Feeding Roller 19: Timing roller 20: Second cleaning device 21: Fixing device 22: Paper ejection roller 30: Developing device 31: Device main body 32: Developer carrier, 32a: Magnet roller 33: Developer transfer supply unit 34: First 1 Developer transport member, 34a: rotary shaft, 34a1: large diameter, 34b: transport blade member 35: partition wall, 35a: first opening, 35b: second opening, 35c: intermediate opening 37: th 2 Developer transport member, 37a: Rotating shaft, 37a1: Large diameter, 37b: Transport blade member 40: Toner replenishing device 41: Toner replenishing port D: Developer L1: The diameter of the rotating shaft of the second developer transport member Height of intermediate opening in the portion having the maximum diameter L2: Height of the intermediate opening in the portion where the diameter of the rotating shaft of the first developing agent conveying member becomes the maximum diameter S: Paper φ1: Of the second developing agent conveying member Maximum diameter of the large part φ2: Maximum diameter of the large part of the first developer transfer member ω: The horizontal line connecting the rotation center of the second developer transfer member 37 and the rotation center of the first developer transfer member 34 Angle that tilts counterclockwise with respect to

Claims (13)

A developer carrier that holds the developer and conveys it to the image carrier is provided in the main body of the apparatus that houses the developer containing the toner and the carrier, and the rotating shaft is opposed to the developer carrier. The developer transporting member, which is provided with a transporting blade member on the outer periphery, is rotated to feed the developing agent to the developing agent carrier while transporting the developer along the axial direction of the developer carrier. A developer circulation transport unit that is provided with a supply unit and that rotates a second developer transport member provided with a transport blade member on the outer periphery of the rotating shaft to transport the developer in the opposite direction to the developer transport supply unit. The developer transport supply unit and the developer circulation transport unit are separated by a partition wall provided along the axial direction of the developer carrier, and the developer is transported and supplied to the end of the partition wall. A first opening for guiding the developer from the developer circulation transport section and a second opening for guiding the developer from the developer circulation transport section to the developer transport supply section are provided, and the developer is passed through each opening. In a developing device that circulates between a developer transport unit and a developer circulation transport unit.
An intermediate opening for moving the developer between the developer transport supply unit and the developer circulation transport unit in the middle portion between the first opening and the second opening at the end of the partition wall. The developing apparatus is characterized in that the diameter of the rotating shaft at at least one of the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening is increased. The developing apparatus according to claim 1, wherein the diameters of the rotating shafts of both the first developing agent conveying member and the second developing agent conveying member at the position of the intermediate opening are increased. In the developing apparatus according to claim 2, the developing apparatus is provided at a position where the maximum diameter portion of the rotating shaft of the first developer conveying member and the maximum diameter portion of the rotating shaft of the second developing agent conveying member do not face each other. A developing device characterized by being In the developing apparatus according to claim 3, the portion having the maximum diameter of the rotating shaft in the first developer conveying member and the portion having the maximum diameter of the rotating shaft in the second developing agent conveying member are respectively provided through an intermediate opening. A developing apparatus characterized in that it is provided at a position upstream of the position of the maximum diameter portion of the rotating shaft of the other facing developing agent conveying member in the developing agent conveying direction by each developing agent conveying member. In the developing apparatus according to any one of claims 2 to 4, the portion where the diameter of the rotating shaft in the first developer conveying member is increased and the diameter of the rotating shaft in the second developing agent conveying member. A developing apparatus characterized in that a portion having an increased diameter partially overlaps at a position facing each other via the intermediate opening. In the developing apparatus according to any one of claims 1 to 5, the length of a portion of the first developer transporting member and the second developer transporting member where the diameter of the rotating shaft is increased is the length of the portion. A developing device characterized in that it is shorter than the length of the intermediate opening. In the developing apparatus according to any one of claims 1 to 6, the transport blade member provided in a portion of the first developer transport member and the second developer transport member where the diameter of the rotating shaft is large. A developing device characterized by changing the pitch or the number of threads. In the developing apparatus according to any one of claims 1 to 7, a developing agent is provided in the first developing agent conveying member and the second developing agent conveying member in order to provide a portion having a large diameter of the rotating shaft. A developing device characterized by continuously increasing the diameter of the rotating shaft from the upstream side to the downstream side in the transport direction. In the developing apparatus according to claim 8, when the diameter of the rotating shaft in the first developing agent conveying member and the second developing agent conveying member is continuously increased, the diameter of the rotating shaft is tapered to the maximum diameter. A developing device characterized in that it is formed in a shape. In the developing apparatus according to any one of claims 1 to 9, the rotating shaft is provided in the first developer conveying member and the second developing agent conveying member with a portion having a large diameter of the rotating shaft. When the distance from the maximum diameter to the maximum diameter is α and the distance from the maximum diameter to the original constant diameter of the rotating shaft is β, the condition of α> β is satisfied. A featured developing device. With the developing apparatus according to any one of claims 1 to 10 set, a line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member. When the angle formed by the horizontal line is ω, the maximum diameter of the rotating shaft of the second developer transport member at the intermediate opening is φ1, and the maximum diameter of the rotating shaft of the first developer transport member is φ2.
When the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is horizontal (ω = 0 °), the condition of (φ1 / φ2) = 1 is satisfied.
The first developer transfer member is located diagonally above the second developer transfer member, and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is relative to the horizontal line. When it is tilted counterclockwise (90 °>ω> 0 °), the condition of (φ1 / φ2)> 1 is satisfied.
The first developer transport member is located diagonally below the second developer transport member, and the line connecting the rotation center of the second developer transport member and the rotation center of the first developer transport member is relative to the horizontal line. A developing apparatus characterized in that the condition of (φ1 / φ2) <1 is satisfied when it is tilted clockwise (0 °>ω> −90 °). With the developing apparatus according to any one of claims 1 to 10 set, a line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member. The angle formed by the horizon is ω, the height of the intermediate opening at the portion where the diameter of the rotating shaft of the second developing agent conveying member at the intermediate opening is the maximum diameter is L1, and the height of the rotating shaft of the first developing agent conveying member is L1. When the height of the intermediate opening in the portion where the diameter becomes the maximum diameter is L2,
When the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is horizontal (ω = 0 °), the condition of (L1 / L2) = 1 is satisfied.
The first developer transfer member is located diagonally above the second developer transfer member, and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is relative to the horizontal line. When it is tilted counterclockwise (90 °>ω> 0 °), the condition of (L1 / L2)> 1 is satisfied.
The first developer transfer member is located diagonally below the second developer transfer member, and the line connecting the rotation center of the second developer transfer member and the rotation center of the first developer transfer member is relative to the horizontal line. A developing apparatus characterized in that the condition (L1 / L2) <1 is satisfied when it is tilted clockwise (0 °>ω> −90 °). An image forming apparatus comprising the developing apparatus according to any one of claims 1 to 12.

Images