JP2001249544A - Developing device, process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of realizing the facilitation of work for replenishing the developing device with initial developer consisting of carrier and toner, eliminating the need of spending time to make the developer reach to prescribed concentration, obtaining high convenience, realizing the reduction of cost and saving space, preventing an image defect such as fogging or density irregularity, and shortening or eliminating time for recovering sequence performed after reattaching the developing device to a device main body by incorporating a developer enclosing container in which the initial developer is previously enclosed in a two-component replenishing type developing device, and to provide a process cartridge equipped with it and an image forming device equipped with them. SOLUTION: The upper part of a screw 7 arranged near a developing sleeve 6 is covered with the lower surface 18b of the developer enclosing container 18 in which the initial developer consisting of the carrier and the toner is enclosed, and a partitioning wall 15 between a developing chamber 5a in which the screw 7 is arranged and a stirring chamber 5b in which a screw 8 is arranged and which is adjacent to the chamber 5a is constituted to come in contact with the lower surface 18b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art Conventionally, in a replenishment type developing device which visualizes an electrostatic latent image on an image carrier using a two-component developer composed of a toner and a carrier, a service is required before the developing device is used. A method in which a man or a user supplies an initial developer (hereinafter, referred to as a “starting agent”) composed of a carrier and a toner mixed in a predetermined ratio in advance to a developing device and then installs the carrier in the main assembly of the developing device. In general, an operation of replenishing toner to a developing device until a predetermined mixing ratio is achieved after the toner is sealed in a main body of the apparatus and thereby making the developing device usable can be performed.

Further, in order to improve the above-mentioned technology and to enhance the convenience of replacement of the developing device by a user, a developer enclosing container in which a starting agent is previously sealed is enclosed in a two-component replenishing system developing device. Therefore, there is a demand for a highly convenient developing device that can easily perform the replenishing operation of the starting agent and does not require time consumption to reach a predetermined concentration of the developer.

For example, as shown in FIG. 4, a developer enclosing container 51 in which a starter is enclosed is provided in a developer container 53, and a toner seal 52 provided in the developer enclosing container 51 is pulled out to perform development. There has been proposed a developing device 50 in which a start agent sealed in an agent enclosing container 51 is supplied to a developer container 53.

[0005]

However, in the above-mentioned conventional example, as shown in FIG.
After the starter sealed in the container is pulled out of the toner seal 52 provided in the developer container 51 and supplied to the developer container 53, the inside of the developer container 51 becomes empty and the developer container A space formed by the empty developer container 51 above the screws 54 and 55 serving as the developer transport member because the toner seal 52 that has shielded between 53 and the developer container 51 is removed. Is generated, and the developer t in the developer container 53 largely moves through this space.

As a result, for example, when the user takes out the developing device 50 from the image forming apparatus main body (not shown) and tilts it, the developer t in the developer container 53 is extremely deviated, and the developing device 50 Since there is a risk of causing image defects such as fog and density unevenness in which the developer t adheres to a region which is originally a white background after being inserted into the image forming apparatus main body, the developing device
A long return sequence after re-installation of 50 was required.

[0007] In some cases, there is a possibility that the above-mentioned image defects may occur due to insufficient conditions.

[0008] The present invention is to solve the above problems,
The purpose of this is to provide a two-component replenishment system developing device with a developer enclosing container in which an initial developer consisting of a carrier and a toner is enclosed in advance. It does not require time consumption to reach a predetermined density, is highly convenient, is inexpensive and saves space, prevents image defects such as fog and density unevenness, and re-installs the developing device on the main unit. An object of the present invention is to provide a developing device capable of shortening or eliminating the time of a return sequence after the process, a process cartridge having the same, and an image forming apparatus having the same.

[0009]

According to a first aspect of the present invention, there is provided a developing apparatus including: a developer container for storing a developer; a developer carrying member for carrying and transporting the developer; A first developer transport member that is disposed in proximity to the carrier and substantially parallel to the developer carrier, and that rotates to transport the developer to the developer carrier; and a first developer transport member. A second developer transport member that is disposed substantially parallel to the developer carrier on the opposite side and that transports the developer in a direction opposite to the first developer transport member by rotating; The first and second developer conveying members are disposed between the first and second developer conveying members, and the developer flows between intermediate portions other than both ends in the longitudinal direction of the first and second developer conveying members. Consisting of a carrier and toner mixed at a predetermined ratio And a developer enclosing container in which the initial developer is sealed and capable of supplying the initial developer to the developer container from an opening provided substantially below the first developer. An upper wall that covers an upper part of the first developer conveying member substantially in the vicinity of the conveying member is also used.

According to the present invention, as described above, the developer enclosing container is provided near the first developer conveying member disposed close to the developer carrying member. The space around the first developer conveying member which is closest to the developer carrier, which has a relatively large effect on the quality of image formation because it also functions as the upper wall covering the upper part, is used to seal the developer after the initial developer supply. By eliminating a space in which the developer can freely move in the container, an extremely small amount of the developer can be formed around the first developer conveying member which is inexpensive, saves space, and is arranged closest to the developer carrier. Deviation can be prevented, and even if the developer is slightly deviated, it can be eliminated instantaneously, thereby preventing image defects such as fog and density unevenness.

Further, it is possible to shorten or eliminate the time of the return sequence after the re-mounting of the developing device to the image forming apparatus main body.

An upper wall of the developer enclosing container for covering above the first developer transport member; and a first developer transport member extending on a normal line from a rotation center of the first developer transport member. It is preferable that the maximum distance between the member and the outer trajectory drawn during rotation be set to 6 mm or less.

It is preferable that an upper wall of the developer enclosing container, which covers an upper part of the first developer conveying member, is in contact with the partition wall.

[0014] Further, the developer enclosing container has an opening formed over substantially the entire area in the longitudinal direction for discharging the initial developer into the developer container, A seal member having an extension part whose one end in the direction is folded back and drawn out of the developing device main body, and a seal member having the opening directed substantially downward and attached to the developing device main body with the opening facing the developer container. It is preferable to have the mounting portion.

It is preferable that the developer enclosing container has a substantially rectangular parallelepiped shape.

Further, a process cartridge according to the present invention is a process cartridge detachable from an image forming apparatus, and has at least the developing device described above.

An image forming apparatus according to the present invention is an image forming apparatus for forming an image by applying an image forming process including a developing step of developing an image carrier. Wherein the image bearing member is developed by the developing device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment in which the present invention is applied to an electrophotographic printer as an example of a developing device according to the present invention, a process cartridge having the same, and an image forming apparatus having the same will be specifically described. Will be described. FIG. 1 is a cross-sectional explanatory view showing the configuration of an image forming apparatus provided with the developing device according to the present invention, FIG. 2 is a cross-sectional explanatory view showing the configuration of the developing device according to the present invention, and FIG. FIG. 3 is an explanatory cross-sectional view illustrating a configuration of a process cartridge provided.

First, the structure of an image forming apparatus having a developing device according to the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes an electrophotographic photosensitive drum serving as an image carrier, and reference numeral 2 denotes a charging device for uniformly charging the surface of the photosensitive drum 1. Reference numeral 3 denotes an exposure device for forming an electrostatic latent image by exposing the surface of the photosensitive drum 1 uniformly charged by the charging device 2 according to image information.

Reference numeral 4 denotes a developing device for supplying a developer t to the electrostatic latent image formed on the surface of the photosensitive drum 1 to visualize the electrostatic latent image. The developing device 4 includes a developer container 5 for accommodating the developer t. A developing sleeve 6 serving as a developer carrier for carrying and transporting the developer t to supply the photosensitive drum 1 to the photosensitive drum 1, and a driving unit (not shown) disposed close to and substantially parallel to the developing sleeve 6. And the developer t
7 serving as a first developer conveying member for conveying the toner
A second developer transporter disposed substantially parallel to the screw 7 on the side opposite to the developing sleeve 6 and driven to rotate by a driving unit (not shown) to transport the developer t in a direction opposite to the screw 7. And a screw 8 serving as a member. In the present embodiment, the screws 7 and 8 have a diameter of 14 mm.
mm.

Reference numeral 9 denotes a toner replenishing device for replenishing the developing device 4 with the developer t (toner), and reference numeral 10 denotes a transfer device arranged to face the photosensitive drum 1. When a transfer material P such as a sheet material made of paper or synthetic resin fed by a transfer material feeding device (not shown) is conveyed between the photosensitive drum 1 and the transfer device 10, the transfer material P Photoconductor drum 1
The toner image formed on the surface of the toner image is transferred onto the transfer material P, and is heated and pressurized when passing through the fixing device 11 to permanently fix the toner image on the transfer material P, and then discharged outside the machine. You.

Reference numeral 12 denotes a cleaning device for removing residual toner remaining on the surface of the photosensitive drum 1. Reference numeral 13 denotes a storage device installed in the developing device 4. In this embodiment, a readable and writable EP-ROM is used. Storage device
Reference numeral 13 denotes a case where the cartridge of the developing device 4 is electrically connected to the engine controller 14 by setting the cartridge of the developing device 4 in the main body of the image forming device A, so that information of the cartridge of the developing device 4 can be read and written from the image forming device A side. .

In this embodiment, an initial developer concentration (standard value) composed of a carrier and a toner mixed at a predetermined ratio and stored at the time of initial setting of the developing device 4 is stored in the storage device 13. In order to supply toner from the printer 9, an appropriate amount of toner is supplied at any time in response to a request for supply toner from the engine controller 14.

As shown in FIG. 2, a developing chamber 5 a having a screw 7 closest to the developing sleeve 6 by a partition wall 15 is provided inside a developer container 5 provided in the developing device 4.
And a stirring chamber 5 b having a screw 8.

A developer t in which toner particles and magnetic carrier particles are mixed is accommodated inside the developing chamber 5a and the stirring chamber 5b, and a partition wall 15 disposed between the screw 7 and the screw 8 is The developer 7 is prevented from flowing at intermediate portions other than both ends in the longitudinal direction of the screws 7 and 8.

Above the stirring chamber 5b, there is provided a toner replenishing device 9 containing replenishment toner composed of non-magnetic toner. A supply port 16 is provided on a side surface of the developing device 4, and an amount of toner corresponding to the toner consumed in the development is dropped and supplied from the toner supply device 9 into the stirring chamber 5b.

As the toner, a known toner in which a coloring agent, a charge controlling agent and the like are added to a binder resin can be used. In the present embodiment, a toner having a volume average particle diameter of 5 to 15 μm is used. On the other hand, as the magnetic carrier, besides magnetic particles such as ferrite, magnetic particles coated with an extremely thin resin are preferably used, and the average particle diameter is preferably 5 to 70 μm.

An opening 5c is formed in a portion of the developer container 5 which is in close proximity to the photosensitive drum 1, and the opening 5c is formed.
A non-magnetic developing sleeve 6, such as aluminum or non-magnetic stainless steel, is rotatably mounted on c. The developing sleeve 6 includes a magnet roller 20 as an internal magnetic field generating means.

The developing sleeve 6 rotates in the direction of the arrow a in FIG. 2 to carry and transport the developer t in which the toner and the carrier are mixed to the developing section where the photosensitive drum 1 is opposed. Then, a thin layer of the developer t formed by being regulated by the developer layer thickness regulating blade 17 comes into contact with the photosensitive drum 1 rotating in the direction of arrow b in FIG. The developer t is supplied to the electrostatic latent image on the surface of the drum 1 to develop a toner image.

Inside the developing device 4, a developing agent having a length substantially the same as the length of the developer container 5 in the longitudinal direction and containing an initial developer composed of a carrier and toner mixed at a predetermined ratio is enclosed. A developer enclosing container 18 is provided, and the developer enclosing container 18 faces the developer container 5 with an opening 18a formed over substantially the entire area in the longitudinal direction of the developer enclosing container 18 facing substantially downward. In this state, it is mounted by a mounting section (not shown) for mounting to the developing device 4 body. The initial developer is supplied from the opening 18a of the developer container 18 into the stirring chamber 5b of the developer container 5.

A developer sealing member 19 serving as a sealing member for sealing the opening 18a is provided in the opening 18a of the developer enclosing container 18.
Is attached, and an extended portion of the developer seal member 19 in which one end in the longitudinal direction is folded is drawn out of the developing device 4 main body.

The developer seal member 19 is in the form of a film, and is preferably made of a polyester film, a nylon film, a polyethylene film, a polypropylene film, a laminated product thereof, or a laminated product of a polyester film and an aluminum foil. is there. In this embodiment, a laminated product of a polyester film, a nylon film, and a polyethylene film is used. In addition, as the attaching method, thermal welding, adhesion, or the like may be used, but in this embodiment, thermal welding is used.

When the initial developer sealed in the developer enclosing container 18 is supplied to the developer container 5, the developer seal member 19 drawn out of the main body of the developing device 4 is moved in the longitudinal direction. When the user grips and pulls out the extension having one end folded, the initial developer drops from the opening 18 a by its own weight and is scattered into the stirring chamber 5 b of the developer container 5.

The outer shape of the developer enclosing container 18 is formed in a substantially rectangular parallelepiped shape. The upper wall 7 also serves as an upper wall that covers the upper side of the upper wall 7. The lower surface 18 b of the developer enclosure 18, which also functions as an upper wall covering the upper part of the screw 7, is in contact with the partition wall 15.

The image forming apparatus A forms an image by applying an image forming process including a developing step of developing the surface of the photosensitive drum 1 serving as an image carrier.

With the above configuration, the user can use the image forming apparatus A
Even when the developing device 4 is detached from the developing device 4 and the developing device 4 is tilted, it is possible to prevent the developer t contained in the developing device 4 from being extremely deviated.

In this embodiment, the lower surface of the developer enclosure 18
Reference numeral 18b is a plane parallel to the screw 7, and is set such that the shortest distance from the outer peripheral path drawn by the screw 7 when rotating is about 2 mm. Also, at this time,
The maximum separation distance Lmax between the lower surface 18b of the developer enclosing container 18 and the outer trajectory drawn when the screw 7 rotates on the normal line from the rotation center of the screw 7 is set to about 5 mm.

According to the above configuration, even if the user detaches the developing device 4 from the image forming apparatus A and tilts the developing device 4 to slightly deviate the developer t, the height of the normal developer t surface is instantaneously increased. Is uniform in the longitudinal direction of the developing device 4 (hereinafter, referred to as
The state returned to "steady state"), and good image development such as fogging and density unevenness was prevented and favorable development was performed.

Further, the developer t cannot be moved from the developing chamber 5a having the screw 7 to the stirring chamber 5b having the screw 8, and the screw 7 closest to the developing sleeve 6, which has a relatively large effect on image formation, is removed. Extreme deviation of the developer t contained in the developing chamber 5a can be prevented.

Further, since almost all the developer t accommodated in the developing chamber 5a exists within the range where the stirring force of the screw 7 can reach, the peak of the biased developer t is instantaneously collapsed. Can be transported.

In this embodiment, the lower surface of the developer enclosure 18 is
18b and the maximum distance Lma between the outer peripheral trajectory drawn by the screw 7 when the screw 7 rotates on the normal line from the rotation center of the screw 7
Although an example in which x is set to about 5 mm has been described, the inventors of the present invention experimented on the biased state of the developer t by changing the maximum separation distance Lmax.
When x is 6 mm or less, the bias of the developer t was instantaneously eliminated, and no image defects such as fog and density unevenness occurred.

When the maximum separation distance Lmax is set to 8 mm or more, it is difficult to eliminate the bias of the developer t, and it takes time to return to the steady state. This is because only a part of the developer t near the screw 7 is stirred and conveyed in the mountain of the one-sided developer t because the one-sided developer t exists outside the range to which the agitating force of the screw 7 can reach. This is because the mountain of the agent t is hardly broken. As a result, image defects such as fog and density unevenness easily occurred.

Therefore, it has been found that the maximum separation distance Lmax is preferably 6 mm or less in order to perform stable and good image formation.

The lower surface 18b of the developer enclosing container 18 also having a function of covering the upper part of the developing chamber 5a having the screw 7 closest to the developing sleeve 6 is in contact with the partition wall 15. Further, the movement of the developer t from the developing chamber 5a having the screw 7 to the stirring chamber 5b having the screw 8 is eliminated, and the extreme deviation of the developer t in the developing chamber 5a having the screw 7 can be reliably prevented. .

With the above configuration, the lower surface of the developer enclosure 18
18b also serves as an upper wall which covers the upper part of the screw 7 which is a first developer conveying member and which is disposed in the vicinity of the developing sleeve 6 which is a developer carrying member. The space around the screw 7 which is closest to the developing sleeve 6 which exerts a relatively large influence is regulated, and a space in which the developer t can freely move in the developer enclosing container 18 after the initial developer is supplied is eliminated to remove fog and the like. Image defects such as density unevenness can be prevented.

Further, it is possible to shorten or eliminate the time of the return sequence after the re-mounting of the developing device 4 to the main body of the image forming apparatus A.

Next, the structure of a process cartridge having a developing device according to the present invention will be described with reference to FIG. In FIG. 3, reference numeral B denotes a process cartridge which is detachable from an image forming apparatus (not shown), and is provided with the developing device 4 described above. The developing device 4 of the present embodiment is configured substantially in the same manner as described above, and can obtain the same effects.

In the present embodiment, the developing device 4 is integrally formed including the photosensitive drum 1, a charging device 2 as a process means acting on the photosensitive member of the photosensitive drum 1, and a cleaning device 12. The process cartridge B is detachable from the image forming apparatus.
Note that the image forming apparatus of the present embodiment is configured in substantially the same manner as the image forming apparatus A described above.

Since the process cartridge B of this embodiment is integrally formed including the photosensitive drum 1, the charging device 2, the developing device 4 and the cleaning device 12, it can be detached from the image forming apparatus main body. These components can be easily replaced, and the maintainability of the image forming apparatus is improved.

Further, by replacing the process cartridge B, important components in the electrophotographic image formation can be collectively replaced with a new one at a time, so that a high quality image can always be maintained.

[0051]

Since the present invention has the above-described structure and operation, the developer enclosing container is provided near the first developer conveying member disposed close to the developer carrying member. The upper peripheral wall that covers the upper portion of the developer transport member also has a relatively large effect on the quality of image formation. By eliminating the space in which the developer can freely move inside the developer enclosing container after the developer is supplied, the first developer transport member is arranged in the cheapest, space-saving and closest to the developer carrier. Can prevent extreme deviation of the developer, and even if the developer is slightly offset, it can be instantly resolved,
This can prevent image defects such as fog and density unevenness.

Further, it is possible to shorten or eliminate the time of the return sequence after the re-mounting of the developing device to the image forming apparatus main body.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view illustrating a configuration of an image forming apparatus including a developing device according to the present invention.

FIG. 2 is an explanatory cross-sectional view illustrating a configuration of a developing device according to the present invention.

FIG. 3 is an explanatory cross-sectional view illustrating a configuration of a process cartridge including a developing device according to the present invention.

FIG. 4 is a diagram illustrating a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photoreceptor drum, 2 ... Charging device, 3 ... Exposure device, 4 ...
Developing device, 5: developer container, 5a: developing chamber, 5b: stirring chamber, 5c: opening, 6: developing sleeve, 7, 8, screw, 9: toner replenishing device, 10: transfer device, 11: fixing device , 12: Cleaning device, 13: Storage device, 14: Engine controller, 15: Partition wall, 16: Supply port, 17: Developer layer thickness regulating blade, 18: Developer enclosure, 18a: Opening, 18b: Lower surface , 19: developer seal member, 20: magnet roller, A: image forming apparatus, B: process cartridge, Lmax: maximum separation distance, P: transfer material, t: developer

Continued on the front page (72) Inventor Seishi Yamaguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H077 AA02 AA06 AA33 AA39 AB02 AB18 AC02 AD06 BA08 EA03 GA04

Claims (7)

[Claims] A developer container accommodating a developer; a developer carrier for carrying and transporting the developer; a developer carrier arranged in proximity to the developer carrier and substantially parallel to the developer carrier; A first developer transport member that transports the developer to the developer carrier by being disposed on the opposite side of the developer carrier with respect to the first developer transport member; A second developer transport member that transports the developer in a direction opposite to the first developer transport member by rotating; a first developer transport member and a second developer transport member; A partition wall disposed between the first and second developer conveying members for preventing the developer from flowing at an intermediate portion other than both ends in the longitudinal direction; and a carrier and toner mixed at a predetermined ratio. The initial developer is sealed, and the initial development is performed through an opening provided substantially below. And a developer enclosing container capable of supplying the developer enclosing container to the developer container, wherein the developer enclosing container covers an upper portion of the first developer conveying member substantially in the vicinity of the first developer conveying member. A developing device, which also serves as a wall. 2. An upper wall of the developer enclosing container which covers an upper part of the first developer transport member, and the first developer transport along a normal line from a rotation center of the first developer transport member. 2. The developing device according to claim 1, wherein a maximum separation distance from an outer peripheral locus drawn when the member rotates is set to 6 mm or less. 3. The device according to claim 1, wherein an upper wall of the developer enclosing container that covers an upper part of the first developer transport member is in contact with the partition wall. Developing device. 4. The developer enclosing container includes an opening formed over substantially the entire area in a longitudinal direction for discharging the initial developer into the developer container, and an opening formed in the developer enclosing container. A sealing member having an extension part whose one end in the direction is folded back and drawn out of the developing device main body; and for mounting the developing device on the developing device main body with the opening facing substantially downward and facing the developer container. The developing device according to any one of claims 1 to 3, further comprising: 5. The developing device according to claim 1, wherein the developer enclosing container has a substantially rectangular parallelepiped shape. 6. A process cartridge detachably mountable to an image forming apparatus, wherein the process cartridge includes at least the developing device according to claim 1. 7. An image forming apparatus for forming an image by applying an image forming process including a developing step of developing an image carrier, wherein the image forming apparatus according to claim 1. Item 7. An image forming apparatus comprising the process cartridge according to Item 6, wherein the image bearing member is developed by the developing device.