JP4804174B2 - Developing device, process cartridge, and electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to a developing device, a process cartridge, and an electrophotographic image forming apparatus that forms an image on a recording medium.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer, etc.), a facsimile machine, a word processor, and the like.

  The developing device has at least a developer carrying member as developing means and is used for an electrophotographic image forming apparatus.

  The process cartridge is a cartridge in which an electrophotographic photosensitive member and at least a developer carrier as a developing unit are integrally formed, and the cartridge can be attached to and detached from the image forming apparatus main body.

  In an electrophotographic image forming apparatus using a conventional electrophotographic image forming process (hereinafter referred to as “image forming apparatus”), an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge. Some cartridges employ a process cartridge that allows the cartridge to be attached to and detached from the image forming apparatus main body. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

  The outline of the configuration of the process cartridge will be described. The process cartridge includes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) as an image carrier. Further, a cleaning device for cleaning the surface of the photosensitive drum, a charging device for applying a charge to the photosensitive drum, and a developing device are provided. The developing device is a developing roller that is a developer carrying member for supplying a developer (hereinafter referred to as “toner”) to the photosensitive drum, a supply / recovering roller (hereinafter referred to as “removing / recovering roller”) that supplies toner to the developing roller, and removes and collects the toner , Simply referred to as “supply roller”), a developing blade for regulating toner on the developing roller, a toner container for storing toner, and the like.

  The configuration of the process cartridge differs depending on the configuration of the image forming apparatus, and the configuration is roughly divided into three types: “all-in-one type”, “rotary system”, and “replenishment system”. For example, the types described in Patent Documents 1 and 2 are called “replenishment systems”.

  Here, a type called “replenishment system” will be described with reference to FIGS. 7 and 8. 7 and 8 are not publicly known at the time of filing this application.

  The process cartridge 8 shown in FIG. 7 is configured by integrating the photosensitive drum 1, the charging roller 2, the developing unit 4, and the cleaning blade 7. The developing unit 4 includes a toner container 16 as a toner container 16a that stores toner replenished from the toner cartridge 9, and a developing container 20 that is a frame that rotatably supports the developing roller 21. The developing roller 21 carries the toner from the toner container 16 and transports it to the surface of the photosensitive drum 1 to develop the latent image on the photosensitive drum 1.

  In addition to the developing roller 21, the developing container 20 includes a developing blade 18 for regulating the toner layer thickness on the developing roller 21, and a supply roller 22 that is a sponge roller for supplying toner onto the developing roller 21. Etc. are provided.

  In the method called “replenishment system” shown in FIG. 7, in order to replenish toner to the process cartridge 8, the toner cartridge 9 containing toner is configured separately from the process cartridge 8, and Each can be installed independently.

  In the “replenishment system” process cartridge 8 shown in FIG. 7, the toner transport chamber 40 is disposed in the toner storage portion 16 a, and a spiral screw (hereinafter referred to as “transport screw”) is transported as a transport member for transporting toner into the toner transport chamber 40. 41) is provided. The conveying screw 41 conveys the toner from the non-driving side to the driving side in the longitudinal direction of the process cartridge 8, the direction indicated by the arrow in FIG. 8, and supplies the toner to the supply roller 22. Further, an opening 42 for supplying and collecting toner between the supply roller 22 and the conveyance screw 41 is provided in the developing container wall 19 disposed between the supply roller 22 and the toner conveyance chamber 40.

That is, the conveying screw 41 collects the toner peeled off from the developing roller 21 by the supply roller 22 again through the opening 42, conveys the toner from the longitudinal non-driving side to the driving side, and conveys it to the toner storage container 16. It also has a role to do.
JP 2003-140458 A JP 2001-249544 A

  In the configuration of the “replenishment system” process cartridge, the toner peeled off from the developing roller 21 by the supply roller 22 is positively conveyed in the region of the non-opening portion in the longitudinal direction of the toner conveyance chamber 40. It is never returned to 41. For this reason, the toner is not sufficiently circulated between the supply roller 22 and the conveying screw 41, and the toner that is not collected by the conveying screw 41 stays at the end of the supply roller in the longitudinal direction. As a result, a phenomenon may occur in which the toner deteriorates and the toner is scattered outside the developing container at the end of the supply roller.

  On the other hand, since the toner scattering amount tends to increase due to the increase in speed and service life that has been required in recent years, a reduction in toner scattering at the end of the supply roller has been further required.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developing device and a process that can improve the developer (toner) circulation capability at the longitudinal end of the supply roller, prevent toner deterioration, and reduce toner scattering outside the developing container. A cartridge and an electrophotographic image forming apparatus are provided.

The above object is achieved by the developing device, the process cartridge, and the electrophotographic image forming apparatus according to the present invention. In summary, according to the first aspect of the present invention, in the developing device used in the electrophotographic image forming apparatus, the developer for developing the electrostatic latent image formed on the electrophotographic photosensitive member using the developer. A carrier;
A supply / recovery rotating member for supplying and collecting the developer with respect to the developer carrier;
A developer container that houses the developer carrier and the supply / collection rotating member to form a developing chamber;
A developer conveying member that supplies the developer to the supply / recovery rotation member and conveys the developer from one end of the supply / recovery rotation member to the other end;
A developer transport chamber for storing the developer transport member;
Have
The developer transport chamber can pass the developer from the developer transport chamber into the developer container in order to supply the developer from the developer transport member to the supply / recovery rotating member. An opening communicating with the developing container and a non-opening where the developer does not pass from the developer transport chamber into the developing container are formed,
(1) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the opening of the developer transport chamber is defined as G1. age,
(2) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the non-opening portion of the developer transport chamber. G2
(3) The supply / collection rotation formed between the end of the supply / collection rotation member in the longitudinal direction of the supply / collection rotation member and the developing container facing the end of the supply / collection rotation member. When the longitudinal clearance of the member is G3,
The relationship between the clearances G1, G2, and G3 is as follows:
G2 <G1 and G2 <G3
And a process cartridge having the developing device.

According to the second aspect of the present invention, an electrophotographic image forming apparatus for developing an electrostatic latent image formed on an electrophotographic photosensitive member into a toner image, and transferring the toner image to a recording medium to form an image. In
A developer storage container forming a developer storage portion for storing a developer used for developing an electrostatic latent image formed on the electrophotographic photosensitive member;
A developer carrying member for conveying the developer to a latent image area on the electrophotographic photosensitive member;
A supply / recovery rotating member for supplying and collecting the developer with respect to the developer carrier;
A developer container that houses the developer carrier and the supply / collection rotating member to form a developing chamber;
A developer conveying member that supplies the developer to the supply / recovery rotation member and conveys the developer from one end of the supply / recovery rotation member to the other end;
A developer transport chamber for storing the developer transport member;
Have
The developer transport chamber can pass the developer from the developer transport chamber into the developer container in order to supply the developer from the developer transport member to the supply / recovery rotating member. An opening communicating with the developing container and a non-opening where the developer does not pass from the developer transport chamber into the developing container are formed,
(1) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the opening of the developer transport chamber is defined as G1. age,
(2) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the non-opening portion of the developer transport chamber. G2
(3) The supply / collection rotation formed between the end of the supply / collection rotation member in the longitudinal direction of the supply / collection rotation member and the developing container facing the end of the supply / collection rotation member. When the longitudinal clearance of the member is G3,
The relationship between the clearances G1, G2, and G3 is as follows:
G2 <G1 and G2 <G3
An electrophotographic image forming apparatus is provided.

  According to the present invention, the developer can be actively circulated in the developer container corresponding to the non-opening portion of the developer transport chamber.

  Hereinafter, a process cartridge and an electrophotographic image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Example 1
FIG. 1 shows a schematic configuration of an embodiment of an electrophotographic image forming apparatus according to the present invention. In this embodiment, the electrophotographic image forming apparatus 100 is a replenishment-type multicolor electrophotographic image forming apparatus (hereinafter simply referred to as “image forming apparatus”) provided with a process cartridge, and particularly in this embodiment. A full-color laser beam printer which is an embodiment of the image forming apparatus.

[Entire configuration of image forming apparatus]
First, an overall configuration of an image forming apparatus 100 that is a full-color laser beam printer in this embodiment will be described with reference to FIGS. 1 and 2.

  The image forming apparatus 100 includes four drum-shaped electrophotographic photosensitive members (hereinafter referred to as “photosensitive drums”) 1 (1a, 1b, 1c, and 1d) arranged in parallel in the horizontal direction. The photosensitive drum 1 is rotationally driven in the direction of an arrow by a driving unit (not shown).

  Around the photosensitive drum 1, a charging roller 2 (2a, 2b, 2c, 2d) is disposed as charging means for uniformly charging the surface of the photosensitive drum 1. Above the photosensitive drum 1, there is provided a scanner unit 3 (3a, 3b, 3c, 3d) as exposure means for irradiating a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1. It is done. Further, around the photosensitive drum 1, a developing unit 4 (4a, 4b,...) That develops a toner image by attaching a developer (hereinafter referred to as “toner”) to the electrostatic latent image on the photosensitive drum 1. 4c, 4d). Further, an intermediate transfer belt 5 for transferring a toner image on the photosensitive drum 1 and a transfer roller 6 (6a, 6b, 6c, 6d) as primary transfer means are disposed below the photosensitive drum 1. .

  The toner image on the intermediate transfer belt 5 is transferred to the recording medium S fed from the paper supply unit 10 by a transfer roller 11 as a secondary transfer unit. The recording medium S to which the toner image has been transferred is fixed by the fixing device 12 and discharged to the outside by the discharge roller 13.

  Further, in this embodiment, around the photosensitive drum 1, there are cleaning blades 7 (7a, 7b, 7c, 7d) as cleaning means for removing the transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer. Is provided.

  Here, the photosensitive drum 1, the charging roller 2, the developing unit 4, and the cleaning blade 7 are integrated to form a process cartridge 8 (8a, 8b, 8c, 8d). Further, in the process cartridge 8, toner cartridges 9 (9a, 9b, 9c, 9d) for supplying toner to the process cartridge 8 are arranged.

  In the following description, the “longitudinal direction” is a direction in which the process cartridge 8 is mounted, and in FIG. 1, the photosensitive material is a direction intersecting (substantially orthogonal) to the transfer material S conveyance direction (arrow A direction). The same direction as the axial direction of the body drum. “Left and right” refers to the left and right when the transfer direction of the transfer material S is viewed from above. Further, “upper and lower” are upper and lower in the mounted state of the process cartridge 8 and the toner cartridge 9.

[Description of process cartridge]
Next, the frame structure of the process cartridge 8 will be described with reference to FIGS.

  As shown in FIG. 3, the process cartridge 8 has a frame structure in which the photosensitive drum unit 14 and the developing unit 4 are integrated in this embodiment. The developing unit 4 is detachably attached to the toner cartridge 9 attached to the image forming apparatus. Therefore, the toner container 16 constituting the developing unit 4 is provided with a toner supply port 34 for receiving toner supply from the toner cartridge 9. In addition, a stirring member 25 is provided in the toner container 16 to stir and mix the replenished toner and the existing toner.

  The photosensitive drum unit 14 includes a cleaning container 15 that is a frame body that rotatably supports the photosensitive drum 1. The cleaning container 15 includes a charging roller 2 that uniformly charges the surface of the photosensitive drum 1 and a cleaning blade 7 that collects waste toner remaining on the surface of the photosensitive drum 1 after development. ing.

  On the other hand, the developing unit 4 develops a developer storage container having a toner storage portion 16a for storing toner replenished from the toner cartridge 9, that is, the toner storage container 16 and a latent image on the surface of the photosensitive drum 1. And a developing container 20 forming a developing chamber 20a. The toner container 16 and the developing container 20 are coupled by ultrasonic welding or the like. In this embodiment, the toner storage portion 16a of the toner storage container 16 and the development chamber 20a of the development container 20 are partitioned by a partition wall, that is, the development container wall 19 to form an integral frame.

  The developing chamber 20 a is provided with a developing roller 21 as a developer carrying member that carries the toner in the developing chamber 20 a and transports it to the photosensitive drum 1, and is rotatably supported by the developing container 20.

  In addition to the developing roller 21, the developing container 20 that forms the developing chamber 20a is provided with a developing blade 18 for regulating the layer thickness of the toner on the developing roller 21. Further, the developing chamber 20a is provided with a supply / collection rotating member 22 as a toner supply and recovery member for supplying toner onto the development roller 21 and for peeling off and collecting the toner on the development roller 21. The rotating member 22 is an elastic rotating body such as a sponge roller in this embodiment. In the following description, the supply / collection rotating member 22 is simply referred to as a “supply roller”. Both ends of the supply roller 22 in the longitudinal direction are rotatably supported by the developing container 20 and are driven to rotate.

  In this embodiment, a developer transport chamber, that is, a toner transport chamber 40 is provided so as to protrude from the developer container wall 19 toward the toner storage container 16, that is, toward the toner storage portion 16 a. The toner transport chamber 40 is provided at a position facing the supply roller 22, and a transport screw 41 that is a developer transport member is disposed in the toner transport chamber 40.

  The conveying screw 41 supplies the toner in the toner container 16 to the supply roller 22, and conveys the toner from the non-driving side to the driving side of the process cartridge along the longitudinal direction of the conveying screw 41 (see FIG. 4). ). The configuration of the toner transfer chamber 40 and the function of the transfer screw 41 will be described in more detail later.

  In the process cartridge 8 of this embodiment, as shown in FIG. 3, coupling portions 50 are provided at both ends of the developing unit 4, and the developing unit 4 and the photosensitive drum unit 14 are coupled by being inserted into the coupling portion 50. The pins 51 are connected. That is, the developing unit 4 is rotatable with respect to the photosensitive drum unit 14 around the connecting pin 51 of the connecting portion 50. Further, the developing unit 4 is urged by a pressure spring 52, whereby the developing roller 21 comes into contact with the photosensitive drum 1.

[Description of toner cartridge]
As shown in FIG. 1, the toner cartridge 9 (9a, 9b, 9c, 9d) is disposed above the process cartridge 8 (8a, 8b, 8c, 8d), and in the present embodiment, as described above, the developing unit 4 Are detachably arranged in parallel. Therefore, as shown in FIG. 2, the toner cartridge 9 (9a, 9b, 9c, 9d) is attached to and detached from the process cartridge 8 (8a, 8b, 8c, 8d) by opening the opening / closing door 101 on the front surface of the apparatus main body 100A. Is possible. Further, the process cartridge 8 (8a, 8b, 8c, 8d) can be attached to and detached from the apparatus main body 100A.

  As shown in FIG. 3, the toner cartridge 9 includes a toner container 30 that contains toner, and has a stirring member 31 inside. Further, a toner supply port 33 communicating with the supply port 34 of the developing unit 4 is provided, and a supply screw 32 is provided in the toner supply port 33. Therefore, the toner in the toner container 30 can be replenished into the toner storage container 16 of the developing unit 4 through the supply port 33 and the replenishment port 34 by rotationally driving the replenishment screw 32.

[Process cartridge toner transport and circulation]
Next, toner conveyance and circulation in the process cartridge 8 will be described with reference to FIGS.

  When the process cartridge 8 is initially used, unused toner is stored in the toner storage container 16. In the present embodiment, as described above, the toner conveyance chamber 40 is disposed in the toner storage container 16, and the conveyance screw 41 is rotatably provided in the toner conveyance chamber 40.

  As shown in FIGS. 3 and 4, the toner conveyance chamber 40 has an opening 42 on the side facing the developing chamber 20 a in order to supply toner from the conveyance screw 41 to the supply roller 22. It is formed. That is, the developing container wall 19 provided on the developing chamber 20 a side of the toner transfer chamber 40 is opened over a predetermined length along the longitudinal direction of the toner transfer chamber 40, and an opening 42 is formed.

  Accordingly, the toner transfer chamber 40 and the developing container 20, that is, the developing chamber 20a are communicated with each other through the opening 42, whereby the toner in the toner transfer chamber 40 is transferred from the toner transfer chamber 40 to the developing chamber 20a. It is possible to pass.

  That is, as shown in FIG. 4, the toner in the toner conveyance chamber 40 is supplied from the conveyance screw 41 to the supply roller 22 through the opening 42.

  However, the both ends in the longitudinal direction of the toner transfer chamber 40 indicated by hatching in FIG. 4, that is, the both sides in the longitudinal direction of the opening 42 are not opened and are closed by the developing container walls 19a and 19b. .

  In other words, in this embodiment, as shown in FIG. 4 (and FIG. 6), both sides of the opening 42 corresponding to both ends of the supply roller 22 in the longitudinal direction of the toner transport chamber 40 are the toner storage portions 16a. And the developing chamber 20a, that is, a non-opening portion closed by the developing container wall 19 (19a, 19b).

  Further, as shown in FIGS. 4 and 6, the toner transfer chamber 40 includes openings 46 and 47 that open to the toner storage portion 16 a side. In other words, in the toner transfer chamber 40, a part of the wall member 43 disposed on the opposite side of the developing chamber 20a is opened at both longitudinal ends of the toner transfer chamber 4 in this embodiment. Openings 46 and 47 are formed.

  The opening 46 is a return opening for returning the toner conveyed in the longitudinal direction by the conveying screw 41 from the toner conveying chamber 40 to the toner accommodating portion 16a, and the opening 47 is from the toner accommodating portion 16a to the toner conveying chamber 40. And a replenishment opening for replenishing toner.

  In this embodiment, as shown in FIG. 4, the return opening 46 and the replenishment opening 47 are each formed at least in regions corresponding to the non-opening portions 19 a and 19 b that form both ends of the toner transfer chamber 40. ing.

  With the above configuration, the transport screw 41 in the toner transport chamber 40 is driven by the apparatus main body 100A after the process cartridge 8 is mounted on the apparatus main body 100A, and transports toner. When driven, the toner stored in the toner storage portion 16 a of the process cartridge 8 is supplied into the toner transfer chamber 40 through the supply opening 47 of the toner transfer chamber 40, that is, supplied to the transfer screw 41. The toner supplied to the conveying screw 41 is moved from one end side to the other end side along the longitudinal axis direction of the conveying screw 41, that is, in this embodiment, as shown in FIG. Is conveyed in the direction of the arrow from the drive side to the drive side.

  The toner transported to the drive side of the transport screw 41 passes through the return opening 46 and is returned to the toner storage portion 16a. The toner returned to the toner storage portion 16a is agitated and mixed with the existing toner in the toner storage portion 16a by the agitating member 25, conveyed to the replenishment opening 47 side, and again through the replenishment opening 47 to the toner conveyance chamber. 40 is supplied.

  On the other hand, the toner supplied from the opening 42 of the toner transfer chamber 40 to the supply roller 22 is sent to the developing roller 21 via the supply roller 22 and further supplied to the photosensitive drum 1 for development. . Then, the toner on the developing roller 21 that has not been supplied to the photosensitive drum 1 is peeled off by the supply roller 22 and collected to the conveying screw 41.

[Configuration for improving the toner circulation capacity in the developing container of the process cartridge]
Next, with reference to FIG. 4 to FIG. 6, a configuration for improving the toner circulation capability that constitutes the characterizing portion of the present invention will be described.

  In the region where the opening 42 is formed in the toner transfer chamber 40, as shown in FIG. 5, the toner from the developing roller 21 peeled off by the supply roller 22 is positively transferred through the opening 42. Returned to the screw 41.

  On the other hand, at both ends of the opening 42 of the toner transfer chamber 40, that is, at both ends in the longitudinal direction of the supply roller 22 shown by hatching in FIG. 4, the toner transfer chamber 40 has non-opening portions 19a and 19b. Has been. That is, as shown in FIG. 6, the non-opening portions 19a and 19b have no opening in the short direction. Therefore, the toner from the developing roller 21 peeled off by the supply roller 22 is not positively returned to the conveying screw 41 in the non-opening portions 19a and 19b.

  Here, the structure of the developing chamber 20a will be described.

  As shown in FIGS. 3 and 4, the developing container 20 constituting the developing chamber 20 a is positioned along the longitudinal direction of the supply roller 22. The developing container 20 includes a curved developing container bottom wall 23 extending to the developing container wall 19 of the toner transfer chamber 40 and a developing container side wall 24 that supports the longitudinal axis of the supply roller 22. .

  Further, the developing container bottom wall 23 is formed in a step shape in the longitudinal direction of the developing chamber 20a. That is, the bottom walls 23a and 23b are formed in steps.

  That is, the bottom wall 23 a of the developing container 20 corresponding to the opening 42 of the toner transfer chamber 40 is the bottom of the developing container 20 corresponding to the non-opening portions 19 a and 19 b located at both ends of the opening 42 of the toner transfer chamber 40. The wall 23b is formed so that the radial distance (clearance) from the supply roller 22 is different.

Here, as shown in FIG.
(1) Radial clearance of the supply roller 22 formed between the supply roller 22 and the development container 20 (that is, the development container bottom wall 23a) in the development container 20 corresponding to the opening 42 of the toner conveyance chamber 40. Is G1,
(2) The radius of the supply roller 22 formed between the supply roller 22 and the development container 20 (that is, the development container bottom wall 23b) in the development container 20 corresponding to the non-opening portions 19a and 19b of the toner transfer chamber 40. The clearance in the direction is G2. Also,
(3) Longitudinal direction of the supply roller 22 formed between the end 22a of the supply roller 22 in the longitudinal direction of the supply roller 22 and the developing container 20 (developing container side wall 24) facing the end 22a of the supply roller 22 Let G3 be the clearance.

  According to the present embodiment, the clearance G1 is 1.1 to 1.9 (mm), the clearance G2 is 0.7 to 1.3 (mm), and the clearance G3 is 1.1 to 1.9 (mm). Good values could be obtained by setting each numerical value and satisfying the relationship of G2 <G1 and G2 <G3.

  That is, under the above conditions, as shown in FIG. 4, the toner that cannot enter between the supply roller 22 and the developing container 20 is between the end of the supply roller 22 and the developing container 20 (developing container side wall 24). It is possible to escape to the clearance G3. As a result, a toner flow as shown at the non-driving side end in FIG. 4 is generated in the longitudinal direction of the supply roller 22 in the developing chamber 20a, and the toner outside the range of the opening 42 is transferred to the opening 42 and the conveying screw. It extrudes toward 41 and is made to collect | recover with the conveyance screw 41. FIG.

  This can prevent toner deterioration and scattering at the end of the supply roller. Accordingly, the toner scattered outside the developing container can be dropped onto the output image, and the toner can be prevented from scattering outside the cartridge due to vibration during user operation when the cartridge is attached or detached, thereby improving user operability.

  According to the present invention, it is only necessary to satisfy the above-described configuration, and the conditions of G2 <G1 and G2 <G3, and it is not necessary to limit to the numerical values given in the present embodiment.

  The above-described configuration of the present invention can be applied to the end portions on both sides in the longitudinal direction of the supply roller 22.

  In the above embodiment, the process cartridge has been described. However, the present invention is applicable to an image forming apparatus and a developing apparatus having at least a developer carrier.

  The image forming apparatus according to the present invention has been described as a replenishment system and a horizontal inline color image forming apparatus using an intermediate transfer belt. However, the present invention is not limited to this. That is, the present invention can be similarly applied to an image forming apparatus in which a recording medium is conveyed by a transfer belt and a toner image is directly transferred from the photosensitive drum to the recording medium.

  The image forming apparatus of the present invention is not limited to an image forming apparatus to which a process cartridge can be attached and detached, and is not limited to a multicolor image forming apparatus. The principle of the present invention is that an image forming apparatus including a developing device configured to supply toner from a developer transport chamber to a supply / collection rotating member and recover toner from the supply / collection rotating member to the developer transport chamber. It can be widely applied to and can achieve the same effect.

  Since the image forming apparatus having various configurations described above is well known to those skilled in the art, a detailed description thereof will be omitted.

1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus according to the present invention. FIG. 3 is a perspective view showing a state where a process cartridge and a toner cartridge are mounted on the image forming apparatus. It is sectional drawing which shows one Example of the process cartridge which concerns on this invention. FIG. 4 is an explanatory diagram showing a developing chamber and a toner transport chamber viewed from the supply roller side in order to explain the toner transport state in the toner transport chamber and the toner storage unit, and the clearance between the supply roller and the developing container. FIG. 5 is a cross-sectional view of the process cartridge taken along line aa in FIG. 4. FIG. 5 is a cross-sectional view of the process cartridge taken along line bb in FIG. 4. It is sectional drawing which shows the process cartridge of a supply system. FIG. 4 is an explanatory diagram illustrating a developing chamber and a toner conveyance chamber as viewed from a supply roller side in order to describe a toner conveyance state in a toner conveyance chamber and a toner storage unit.

Explanation of symbols

S Recording medium 1 Photosensitive drum (electrophotographic photosensitive member)
2 Charging roller (charging means)
3 Scanner unit (exposure device)
4 Development unit 5 Intermediate transfer belt 6 Transfer roller (primary transfer means)
7 Cleaning Blade 8 Process Cartridge 9 Toner Cartridge 10 Paper Feed Unit 11 Transfer Roller (Secondary Transfer Unit)
12 Fixing Device 14 Photosensitive Drum Unit 15 Cleaning Container 16 Toner Storage Container (Developer Storage Container)
16a Toner storage part 19 Partition wall (developer container wall)
19a, 19b Non-opening portion 20 Developer container 20a Developer chamber 21 Developer roller (developer carrier)
22 Supply roller (supply / recovery rotating member)
22a Supply roller end 23, 23a, 23b Developing container bottom wall (developing container wall)
24 Development container bottom wall (development container wall)
30 toner container 40 toner transfer chamber (developer transfer chamber)
41 Conveying screw (developer conveying member)
42 opening 46 return opening 47 supply opening 100 image forming apparatus

Claims (7)

In a developing device used in an electrophotographic image forming apparatus,
A developer carrying member for developing the electrostatic latent image formed on the electronic photosensitive member with a developer,
A supply / recovery rotating member for supplying and collecting the developer with respect to the developer carrier;
A developer container that houses the developer carrier and the supply / collection rotating member to form a developing chamber;
A developer conveying member that supplies the developer to the supply / recovery rotation member and conveys the developer from one end of the supply / recovery rotation member to the other end;
A developer transport chamber for storing the developer transport member;
Have
The developer transport chamber can pass the developer from the developer transport chamber into the developer container in order to supply the developer from the developer transport member to the supply / recovery rotating member. An opening communicating with the developing container and a non-opening where the developer does not pass from the developer transport chamber into the developing container are formed,
(1) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the opening of the developer transport chamber is defined as G1. age,
(2) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the non-opening portion of the developer transport chamber. G2
(3) The supply / collection rotation formed between the end of the supply / collection rotation member in the longitudinal direction of the supply / collection rotation member and the developing container facing the end of the supply / collection rotation member. When the longitudinal clearance of the member is G3,
The relationship between the clearances G1, G2, and G3 is as follows:
G2 <G1 and G2 <G3
A developing device characterized by that.   A developer storage container that forms a developer storage portion for storing a developer used for developing the electrostatic latent image on a side opposite to the side on which the developer carrier is provided in the developer transport chamber. The developer transport chamber is located on the developer storage container side, and the developer transported in the longitudinal direction of the supply / collection rotating member is provided from the developer transport chamber to the developer storage section. 2. The developing device according to claim 1, further comprising: a return opening that returns to the top and a replenishment opening that replenishes the developer from the developer accommodating portion to the developer transport chamber. The developing device according to claim 2 , wherein the return opening and the replenishment opening are formed at least in a region corresponding to the non-opening portion of the developer conveyance chamber.   4. A process cartridge comprising the developing device according to claim 1 and the electrophotographic photosensitive member, wherein the process cartridge is detachable from the electrophotographic image forming apparatus. In an image forming apparatus for developing a latent image formed on an electrophotographic photosensitive member to form a toner image and transferring the toner image to a recording medium to form an image,
A developer container that forms a developer container for storing a developer used for developing the latent image;
A developer carrier for conveying the developer to the latent image;
A supply / recovery rotating member for supplying and collecting the developer with respect to the developer carrier;
A developer container that houses the developer carrier and the supply / collection rotating member to form a developing chamber;
A developer conveying member that supplies the developer to the supply / recovery rotation member and conveys the developer from one end of the supply / recovery rotation member to the other end;
A developer transport chamber for storing the developer transport member;
Have
The developer transport chamber can pass the developer from the developer transport chamber into the developer container in order to supply the developer from the developer transport member to the supply / recovery rotating member. An opening communicating with the developing container and a non-opening where the developer does not pass from the developer transport chamber into the developing container are formed,
(1) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the opening of the developer transport chamber is defined as G1. age,
(2) A radial clearance of the supply / recovery rotation member formed between the supply / recovery rotation member and the development container in the developer container corresponding to the non-opening portion of the developer transport chamber. G2
(3) The supply / collection rotation formed between the end of the supply / collection rotation member in the longitudinal direction of the supply / collection rotation member and the developing container facing the end of the supply / collection rotation member. When the longitudinal clearance of the member is G3,
The relationship between the clearances G1, G2, and G3 is as follows:
G2 <G1 and G2 <G3
An electrophotographic image forming apparatus, wherein   In the developer transport chamber, the developer transported in the longitudinal direction of the supply / collection rotating member located on the developer storage container side is returned from the developer transport chamber to the developer storage section. 6. The electrophotographic image forming apparatus according to claim 5, wherein a return opening and a replenishment opening for replenishing the developer from the developer accommodating portion to the developer transport chamber are formed. The electrophotographic image forming apparatus according to claim 6 , wherein the return opening and the replenishment opening are formed at least in a region corresponding to the non-opening portion of the developer transport chamber.

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