JPH0683181A - Image forming device provided with process cartridge and developing device - Google Patents

Abstract

PURPOSE:To obtain an image forming device provided with a process cartridge capable of performing excellent development with toner of respective colors without installing a mechanism for discriminating the process cartridge or a means for switching developing bias as for the image forming device in which an image is formed by exchanging the respective process cartridges housing black and chromatic toner. CONSTITUTION:The diameter of a developer carrier 43 in the process cartridge C housing the non-magnetic one-component chromatic toner is made larger than that of the process cartridge housing the magnetic one-component black toner (not shown in figure), and a space between the developer carrier 43 and a latent image carrier 1 is made narrower than that in the case of the process cartridge for black. The diameter of the image carrier 1 and developing bias impressed between the latent image carrier 1 and the developer carrier 43 are set equal regardless of the kind of the process cartridge.

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 or a printer for forming an image by an electrophotographic method and a developing apparatus used therein.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic process comprises a latent image carrier, a charging device, a developing device, a cleaning device, an exposure device, a transfer device, a transfer material conveying device and the like. However, since the latent image carrier, the charging device, the developing device, and the cleaning device, which are involved in the image process until the image is formed on the transfer material, have a relatively short life compared to the above-mentioned other components, they are integrated as a process cartridge. ,
An image forming apparatus having a structure that can be detachably attached to the apparatus body has been put into practical use. Therefore, in such an apparatus, a cartridge having a developing device using a black toner or a cartridge having a developing device using a color toner such as blue or red is prepared, and an image of a desired color is obtained only by replacing them. It is possible.

For example, the process cartridge 1 shown in FIG.
As shown in the sectional view of FIG.
After being uniformly charged by 5, the latent image is formed by the image exposure L, and the toner in the toner hopper 142 of the developing device 104 is supplied on the developing sleeve 140 with the amount regulated by the developing blade 141, and the toner image is formed. Is formed. The toner image on the photoconductor 102 is transferred onto a sheet from the opening 106 of the process cartridge 100 by a charger (not shown). After that, the toner remaining on the photoconductor 102 is scraped off by the cleaning blade 130 of the cleaning device 103, and the toner storage unit 132
Stored in.

FIG. 14 is an enlarged sectional view of the developing sleeve 140 in the vicinity of both ends in the longitudinal direction. Here, the developing device casing 10 is shown.
The seal member 101, which is an elastic body such as felt or foam rubber, is squeezed to some extent so that toner does not leak from the gap between the developing roller 140 and the developing sleeve 140 and the developing blade 141. FIG. 15 is a diagram of FIG. 14 viewed from the left side. However, in FIG. 15, the developing sleeve 14
0 is omitted.

Further, the developing blade 141 regulates the amount of toner at a constant distance t from the developing sleeve 140 as shown in FIG. 14, and the developing blade having elasticity such as rubber as shown in FIG. 43 is the developing sleeve 1
In some cases, the toner sealing member 120 is contacted with the developing blade 143 and the developing sleeve 140 as shown in FIG.
In some cases, a protrusion 120c is provided to prevent toner from leaking from the end of the developing blade 143.

Further, conventionally, in an image forming apparatus such as a copying apparatus, an image forming / recording apparatus, a printer, a facsimile, etc., an electrostatic latent image formed on a latent image carrier made of an electrophotographic photosensitive member, an electrostatic recording dielectric or the like is used. The image is developed by a developing device and visualized as a toner image.

As one of such developing devices, various dry one-component developing devices have been proposed and put into practical use. However, it is difficult to form a thin layer of toner, which is a one-component developer, on the developer carrier with any of the developing devices.

However, at the present time when improvement in resolution, sharpness and the like of an image forming apparatus is required, development of a toner thin layer forming method and its apparatus is indispensable.
Several measures have been proposed for this.

For example, as shown in JP-A-54-43038, an elastic blade made of rubber or metal is brought into contact with the developing sleeve of the developer carrying member, and the elastic blade is brought into contact with the developing sleeve. There is a method in which a thin layer of toner is formed on the developing sleeve by passing the toner between the portions to regulate the toner, and friction at the contact portion imparts sufficient tribo to the toner.

In this case, when the non-magnetic toner is regulated by the elastic blade, a toner supply member for supplying the toner onto the developing sleeve is required separately. this is,
In the case of magnetic toner, the magnetic force of the magnet in the developing sleeve can supply the toner onto the developing sleeve.
This is because the non-magnetic toner cannot supply the toner by magnetic force.

Therefore, a developing device as shown in FIG. 23 has been proposed. In this conventional developing device, a polyurethane foam that comes into contact with the developing sleeve 203 at a position upstream of the elastic blade 204 in the rotational direction of the developing sleeve 203 in a developer container 202 containing a non-magnetic toner 206 as a one-component developer. Provided with an elastic roller 205 using a foam made of sponge, or a fur brush,
By rotating in the direction of arrow c, the developing sleeve 203
The toner 206 is supplied to the upper portion, and then the toner 206 is sent to the contact portion between the elastic blade 204 and the developing sleeve 203 as the developing sleeve 203 rotates, and is made a thin layer.
01 is used for developing the electrostatic latent image. Then, the toner 20 remaining on the developing sleeve 203 without being consumed for the development
6 is peeled off by the elastic roller 205, new toner 206 is supplied by the elastic roller 205, and the above operation is repeated.

Further, a flexible seal member 207, which is brought into light contact with the developing sleeve 203, is provided in the toner collecting portion of the developer container 202 to allow passage of the unfixed developing toner 206 and at the same time, the developer container 202. The toner 206 therein is prevented from leaking from the lower portion of the container 202. Further, an end seal member 208 made of a foam material such as Teflon felt, wool felt, or polyurethane foam is provided in the gap between the opening of the developer container 202 and the developing sleeve 203.

In the above developing device, as shown in FIG. 24 when the developing device is viewed from the drum direction, both longitudinal ends of the elastic blade 204 and the longitudinal ends of the seal member 207 are provided between the end seal member 208 and the sleeve 203. It is designed to be sandwiched. The positional relationship in the longitudinal direction is such that h <j ≦ i when the container opening width h, the elastic blade 204 longitudinal width i, and the lower seal 207 longitudinal width j.

With such a structure, a thin layer of the non-magnetic toner 206 can be satisfactorily formed on the developing sleeve 203, and the electrostatic latent image on the photoconductor 201 can be satisfactorily developed. It became possible to faithfully reproduce a solid black image of high density and a wide area, and to always obtain a stable image.
Further, by the action of the lower seal member 207, the developer container 2
It is also possible to prevent the toner 206 in 02 from leaking from the lower portion of the container 202, and also to prevent the toner 206 from leaking from both ends of the elastic blade 204 and the seal member 207 in the longitudinal direction.

[0015]

However, according to each of the above conventional examples, there are the following problems. According to the conventional example in which toners of different colors are prepared for each process cartridge and they are exchanged, the black toner is a magnetic one-component developer, but the color toner is a non-magnetic toner and a magnetic carrier and a two-component developer. In many cases, although the appearance is almost the same as the cartridge, the structure of the developing device is greatly different.

Since these two types of toner have different developing conditions, the cartridge is provided with an identification means such as a protrusion so that the main body of the image forming apparatus to which the cartridge is attached / detached can recognize the black cartridge as a colored cartridge. Then, the latent image potential setting, the developing bias setting, etc. are switched according to the cartridge.

That is, conventionally, in a main body to which a cartridge of a plurality of colors can be attached and detached, it is necessary to provide a changeover switch and an electric circuit for each cartridge, which causes a problem that the structure is complicated and the cost is high.

Further, according to the conventional apparatus shown in FIGS. 14 to 17, the toner seal members 101 and 120 have the curved portion 10 along the developing sleeve 140 of the developing device housing 104.
4a and the developing blade 141 or the portion 104b along the mounting member 144 of the developing blade 141 are bent at a portion 104c which is connected to each other, a gap A may be formed, and the toner passes through the gap A and the seal member 10 passes through the gap A.
There was a problem that it leaked to the outside of 1,120.

Further, when the crushing amount of the toner seal members 101 and 120 is increased so as to eliminate the gap A, the developing sleeve 140 and the toner seals 101 and 120 are increased.
However, there are problems that the contact pressure between the developing blade 140 and the developing blade 140 increases, the torque for rotating the developing sleeve 140 increases, and the assembling property of the developing blade 141 and the developing blade mounting member 144 deteriorates.

Further, according to the conventional example shown in FIG. 23, a small particle size toner 206 having an average particle size of about 8 μm, especially in a low humidity environment.
When the developing operation was repeated a number of times, the toner 206 spilled out from the lower part of the opening at both longitudinal ends of the container 202 of the developing device to the outside of the device. This phenomenon occurs due to the following. In the developer container 202, the toner 206 accumulated between the tip of the elastic blade 204 and the developing sleeve 203 (portion A in FIG. 23) is gradually transmitted to both end portions such as the longitudinal direction as the developing operation is repeated, particularly in a low humidity environment. With toner 206
If the fluidity of the toner has improved, or if the toner has a small particle diameter
When 06 is used, the elastic blade 204 reaches both end portions in the longitudinal direction (B portion in FIG. 24). When the amount of the toner 206 reaching both ends of the elastic blade 204 in the longitudinal direction increases, the toner 206 or the developing sleeve 203 is thickly coated in stripes at the portion C in FIG. In the above-mentioned conventional example, since the longitudinal width j of the lower seal 7 is equal to or shorter than the longitudinal width i of the elastic blade 204, the toner 206 thickly coated on the portion C in FIG. It adheres to the lower portion of 208 (portion D in FIG. 24). Then, when the developing operation is repeated, the toner 206 gradually accumulates on the portion D, is scraped off without being allowed to pass into the developer container 202, and spills out of the apparatus.

A first object of the present invention is to solve the above-mentioned problems and, in an image forming apparatus in which a process cartridge accommodating black and colored toners is replaced and used, toners of respective colors can be used without complicating the apparatus. It is an object of the present invention to provide an image forming apparatus provided with a process cartridge capable of forming an image under developing conditions according to the above.

A second object of the present invention is to solve the above problems and to eliminate the gap between the developing sleeve and the seal member without increasing the torque of the developing sleeve and deteriorating the assembling property of the developing blade and the like. It is an object of the present invention to provide a developing device capable of performing.

Further, a third object of the present invention is to solve the above problems and provide a developing device which does not cause toner leakage to the outside of the device from the lower part of the opening at both longitudinal ends of the developer container. Is intended.

[0024]

According to the first invention of the present application,
The first purpose is to integrally have a developer container, a developer carrier, and a latent image carrier in a frame body, and store different types of developers in the developer container to attach / detach to / from the image forming apparatus. An image forming apparatus comprising a plurality of process cartridges that are arranged to be exchangeable, and a voltage applying unit that applies a predetermined voltage between a latent image carrier and a developer carrier in the process cartridge. The process cartridge of (1) has a magnetic one-component process cartridge containing a magnetic one-component developer and a non-magnetic one-component process cartridge containing a non-magnetic one-component developer. Is a latent image carrier having the same diameter as that of the magnetic one-component process cartridge, and the latent image carrier having a diameter larger than that of the magnetic one-component process cartridge. Interval has a short set developer carrying member, said voltage applying means is achieved by being configured to apply a predetermined voltage irrespective of the kind of the process cartridge.

Further, according to the second invention of the present application, the second object is to provide a developer container having an opening, and to dispose the developer container in the longitudinal direction of the opening so that a substantially half circumferential surface is located in the developer container. And a straight portion attached to the outer wall surface of the developer container above the developer carrier at both ends in the longitudinal direction of the developer carrier. A developing device having a curved portion curved so as to be in close contact with a substantially semi-circular surface located inside the developer container, and an end seal member including a curved portion for connecting the curved portion and the straightened portion, This is achieved by forming a projecting portion projecting inward in the longitudinal direction of the developer carrying member on the bent portion of the end seal member.

Further, according to the third invention of the present application, the third object is to provide a developer accommodating container having an opening for accommodating the one-component developer, and the one-component developer arranged in the opening. And a rotatable developer carrier for carrying and transporting the developer carrier, one end of which is attached to the developer container above the developer carrier and the other end of which is in contact with the surface of the developer carrier as a free end. An elastic restricting member provided and a lower seal disposed below the developer carrying member so that one end is attached to the developer accommodating container and the other end is a free end so as to contact the surface of the developer carrying member. A developing member having a member and end seal members arranged so as to contact both the peripheral surface of the developer carrier and the inner wall of the developer container accommodating container at both ends in the longitudinal direction of the developer carrier. In the device, the lower seal member has both longitudinal ends. Is sandwiched between the end seal and the developer carrier, and the longitudinal width thereof is larger than the longitudinal width of the elastic regulating member, and the longitudinal width of the elastic regulating member is the longitudinal length of the opening. This is achieved by setting the width to be larger than the width in the direction.

[0027]

In the first invention of the present application, the magnetic one-component process cartridge contains, for example, a black magnetic one-component developer, and the non-magnetic one-component process cartridge contains a colored non-magnetic one-component developer. Then, these process cartridges are replaced at any time to form an image.
At this time, the voltage application unit of the image forming apparatus applies a predetermined voltage between the latent image carrier and the developer carrier in the process cartridge regardless of the type of the process cartridge. The diameter of the latent image carrier of each process cartridge is set to be the same. However, since the diameter of the developer carrier of the non-magnetic one-component process cartridge is larger than that of the magnetic one-component process cartridge, the area of the developer for the latent image carrier is expanded, and the charge amount of the developer is large. Good development is achieved even with a non-magnetic one-component developer that is harder to develop than a magnetic one-component developer. Further, if the diameter of the developer carrying member is increased, the load on the voltage applying means is correspondingly increased, but the developer carrying member of the non-magnetic one-component process cartridge has a latent image carrying member more than that of the magnetic one-component process cartridge. Since it is set to be close to, the increased amount can be compensated for and a good developer can be formed. Thus, according to the present invention, a good image forming operation can be performed with different types of developers under the same developing conditions without providing a special identification mechanism.

Further, according to the second invention of the present application, a part of the end seal member is attached along the outer wall surface of the developer container above the developer carrier, and the remaining part is the developer of the developer carrier. It is curved so as to come into close contact with the approximately half-peripheral surface located inside the container. At this time, in the bent portion that connects the straight portion attached to the outer wall surface and the curved portion, a minute gap is generated between the surface of the developer carrier. However, since the bent portion is provided with a protrusion protruding inward in the longitudinal direction of the developer carrier, the free end side of the protrusion is in close contact with the surface of the developer carrier. Thus, according to the present invention, developer leakage from the gap is prevented.

Further, according to the third invention of the present application, the developer in the developer accommodating container reaches the contact portion with the elastic regulating member by the rotating operation of the developer carrying member, and the elastic regulating member is provided with a layer thickness. It is transported outside the opening while being regulated. However, when such a developing operation is repeatedly performed, the developer may be deposited on the contact portion, and the developer may reach both end portions of the elastic regulation member in a low humidity environment, for example. Then, when the developer reaching the both ends increases, the developer is coated on the surface of the developer carrier in a stripe shape at the position, and the lower seal of the end seal member provided at both ends of the developer carrier. Deposit on the member side. However, the lower seal member in the present invention is sandwiched between the developer carrying member and the end seal member, and the longitudinal width thereof is larger than the longitudinal width of the elastic regulating member, so that the lower seal member is deposited on the end seal member. Securely seals the developer and prevents the developer from leaking outside the developing device.

[0030]

Embodiments 1 to 8 of the present invention will be described with reference to the drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 are cross-sectional views showing a schematic configuration of a process cartridge of Example 1, FIG. 1 is a cartridge in which a black image using a magnetic one-component positive toner is obtained, and FIG. 2 uses a non-magnetic one-component positive toner. A cartridge for colored toner.

In FIGS. 1 and 2, 1 is a latent image carrier for forming a latent image corresponding to an original image, 2 is a charging roller for charging the latent image carrier to a predetermined potential, and 3 is a developing device for a latent image. A developer is attached to the surface of the carrier 1 to visualize it. A cleaning device 4 removes the developer remaining on the latent image carrier 1. Reference numeral 5 is a frame which is integrally supported by 1-4. These process cartridges C can be attached to the apparatus main body as shown in FIG. 3 is mounted with the black cartridge of FIG. 1, but the colored cartridge of FIG. 2 can be mounted in the same manner.

In the state of FIG. 3, the professional cartridge C is the main body 7
The latent image carrier 1 is connected to a drive device on the main body 7 side while being held at a fixed position by a positioning member (not shown) provided on the.

The document placed on the document table 6 is illuminated by the certification lamp 25 as the document table 6 moves in synchronization with the rotation of the latent image carrier 1 such as the photosensitive drum in the direction of the arrow in the figure. The reflected light is imaged on the latent image carrier 1 by the imaging lens 26. The latent image carrier 1 is preliminarily uniformly charged by the charging roller 2, the original image becomes a latent image, and then the latent image is developed by the developing device 3 to become a visible image, which is moved to a portion facing the transfer charger 27. . On the other hand, the transfer material P in the paper feeding cassette 28 is sent out by separating the topmost one by a paper feeding roller 29 and a separating claw (not shown), and is timed by a registration roller pair 31 to transfer the transfer charger. 27 and the latent image carrier 1 and the above-mentioned visible image is transferred to the transfer material P.
The image is transferred to and separated from the sheet, is sent to the fixing device 33 through the conveying roller 32, is fixed, and is discharged to the outside of the apparatus. On the other hand, the residual developer on the latent image carrier 1 that has continued to rotate from the transfer portion is cleaned by the cleaning device 4.

In this embodiment, since the main body 7 does not identify the type of cartridge, the dark portion potential V _D on the latent image carrier 1 at the time of development V _D = -570 V and the light portion potential V _L =-regardless of the cartridge. It is 150V. In addition, the developer carrier 4
0 and 43 have a rectangular wave AC 1200 as a developing bias,
Vpp 1800 Hz and variable DC (-150 V to -40
0 V) is superimposed and applied.

In both the cartridges of FIGS. 1 and 2, the latent image carrier 1 is a photosensitive drum having a photosensitive layer formed on a conductive base layer of aluminum or the like and has a diameter of 30 mm.
The charging roller 2 is composed of a conductive layer on a conductive cored bar and a resistance layer outside the conductive layer. In this example, as the conductive layer, conductive powder of carbon black was appropriately dispersed in epichlorohydrin rubber to have a volume resistivity of about 1 × 10 ⁶ Ω · cm, and the resistive layer was obtained by appropriately dispersing carbon in PTFE dispersion paint. A surface resistivity of 1 × 10 ⁹ Ω / □ was used. The hardness is about 60 ° according to JIS A. The core metal is longer than the roller portions of the conductive layer and the resistance layer, and is rotatably supported by bearings at both ends, and power is supplied from the main body 7 side through electrodes (not shown) that are in contact with the core metal or the conductive bearings. To be done. The bearing is supported so as to be movable in the pressurizing direction. The charging roller 2 has a diameter of 14 mm and is in contact with the latent image carrier by pressing the bearing with the spring 10, and is rotated by the rotation of the latent image carrier. In addition, the cleaning layer 4 and the frame 5
Is also common.

Developing device 3 for black cartridge shown in FIG.
Is composed of a developer carrying member 40, a layer thickness regulating member 41 pressed against the developer carrying member 40 by a counter, and a fixed magnet roller 42. For the developer carrying member 40, a conductive nonmagnetic material such as aluminum or stainless steel is used by making it hollow.
A rotary drive transmission member such as a gear is provided at the end portion thereof, and when the latent image carrier 1 rotates, the developer carrier 40 also rotates. The layer pressure regulating member 41 is an elastic body such as urethane rubber, and is constantly brought into pressure contact with the developer carrying body at a predetermined contact pressure to bring the layer thickness and charge of the developer conveyed to the vicinity of the latent image carrying body. The layer thickness of the developer on the developer carrier that regulates the amount is 0.
5 to 2.0 mg / cm ² and a charge amount of 5 to 15 μc / g are generally used in the case of a one-component magnetic toner.

The magnet roll 42 has magnetic poles of 2 to 8 poles in the circumferential direction and is arranged in parallel in the axial direction so that the developing device 3
It is fixed to. The magnet roll 42 has a role of attracting the developer to the developer carrier 40. The latent image carrier 1 and the developer carrier 40 are separated by about 300 μm.

On the other hand, the color cartridge of FIG. 2 is for non-magnetic one-component toner. The developer carrying member 43 is also made of aluminum or the like for black, but has a diameter of 20 mm. There is no magnet roll because the developer is non-magnetic.
Reference numeral 44 denotes a layer thickness regulating member which is in contact with the developer carrying member 43. An elastic roller 45 is pressed against the developer carrying member 43 and rotates in the opposite direction to scrape and supply the developer on the developer carrying member 43. The latent image carrier 1 and the developer carrier 43 are separated by about 200 μm. The adhesion of the developer to the non-image area on the latent image carrier 1 is called "fog", which is one of the causes of the image quality deterioration, but this easily occurs when the charge amount of the developer is small. In the case of the magnetic one-component toner, the fog developer can be returned to the developer carrying member 40 by the magnetic force of the magnet roll 42, but the magnetic force cannot be used in the non-magnetic one-component toner, so the charge amount must be set high in advance. Don't do it.
In the cartridge of FIG. 2, the developer amount on the developer carrier is 0.3 to 0.8 mg / cm ² , and the charge amount is 10 to 20 μc.
/ G.

Therefore, when a non-magnetic one-component toner is used as a developer, it is difficult to develop it on the latent image carrier 1 due to the large charge amount of the toner. This is especially true because the developing bias is set under the same condition as the black cartridge using the magnetic one-component toner.

Therefore, the developing device 3 for the color cartridge
Then, the outer diameter of the developer carrier 43 is set to the black developer carrier 4
By making the outer diameter larger than 0, the developing area is increased, and by increasing the opportunity to develop the latent image on the latent image carrier 1, it becomes possible to sufficiently develop the non-magnetic one-component toner having a high charge amount.

Further, even if the main body output of the developing bias is constant, in the color cartridge, the developing carrier 43 has a larger diameter than that for black, and therefore the load becomes large. Therefore, if the actual value is set to 1200 Vpp for the black cartridge, it becomes only 1150 Vpp for the colored cartridge. Therefore, it is necessary to compensate for the decrease in the developing bias by reducing the distance between the developer carrier 43 and the latent image carrier 1.

Since the potential setting on the latent image carrier 1 is the same for the black cartridge and the color cartridge,
The two-component system in which the developer is composed of non-magnetic toner and carrier cannot be used as the developing system for the color cartridge. Because the carrier is also developed depending on the difference between the VDC value of the developing bias and the latent image potential, the latent image carrier 1 and the cleaning device 4 are damaged, and appear as streaks on the image.
Further, the consumption of the carrier causes a change in the ratio of the toner and the carrier, which causes phenomena such as background fog and image density reduction. Conventionally, the two-component developer is used by changing the charging potential of the latent image carrier between the black cartridge and the colored cartridge, but there is a problem that the apparatus becomes complicated.

However, according to the process cartridge of the present invention, it is possible to provide a good image with toner of either black or colored with a simple structure as described above.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 4, the lower surface of the developing device section is
In the case where it also serves as a guide member for transferring the transfer material of the main body of the image forming apparatus, the lower surface of the developing device section must be located at the same position regardless of the kind of the cartridge.

Therefore, in this embodiment, the positions of the developer carrying members 40 and 41 with respect to the latent image carrying member 1 are made different depending on the cartridge. That is, by setting the distance between the image exposure portion on the latent image carrier and the developing area so that the larger one of the developer carrier has a smaller diameter, the same bottom surface can be obtained even in the cartridges having different developer carrier diameters. It is possible to have.

In this embodiment, the color developing device is 20 m
Since the black and black developing device is a developer carrier having a diameter of 16 mm, the difference in radius is only 2 mm, and the difference in dark attenuation of the potential of the latent image carrier is as low as 10 V or less, which does not affect the developability.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the process cartridge according to the third embodiment. After the photoconductor 102 is uniformly charged by the charger 105, a latent image is formed by image exposure L, and the photoconductor 102 serves as a developer container of the developing device 104. The toner T in the toner hopper 142 is supplied on the developing sleeve 140, which is a developer carrying member, in a regulated amount by the developing blade 141 having a constant distance from the developing sleeve 140 to form a toner image. The toner image on the photoconductor 102 is the opening 10 of the process cartridge 100.
At 6, the toner is transferred onto the sheet by a charger (not shown). After that, the toner remaining on the photoconductor 102 is scraped off by the cleaning blade 130 of the cleaning device 103 and stored in the toner storage unit 132.

FIG. 6 is an enlarged cross-sectional view of the developing sleeve 140 in the vicinity of the end portion in the longitudinal direction. Between the developing device housing 104 and the developing sleeve 140 and the developing blade 141, for example, an elastic body such as felt or foam rubber is used. Sealing member 10
1 is provided. FIG. 7 is a view seen from the left side of FIG. However, the developing sleeve 140 is omitted in FIG.

The toner seal member 101 projects inward in the longitudinal direction of the developing sleeve 140 in the vicinity of a bent portion 104c connecting a portion 104a of the developing device housing 104 along the developing sleeve 140 and a portion 104b along the developing blade 141. The portion 101a is provided and the protrusion 1 is provided.
As shown in FIG. 8, a cutout 10 is formed at a part of the root of 01a.
1b is provided.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. The same parts as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 9 shows the case where the developing blade 143 is in elastic contact with the developing sleeve 140. FIG. 3 is an enlarged cross-sectional view of the developing sleeve in the vicinity of the end portion in the longitudinal direction, showing the developing device casing 104, the developing sleeve 140, and the developing blade 1.
43 and the developing blade mounting member 144, for example, a seal member 10 which is an elastic body such as felt or foam rubber.
2 is provided. FIG. 10 is a diagram of FIG. 9 viewed from the left side. However, the developing sleeve 140 is omitted in FIG.

The toner seal member 120 is provided with a protrusion 120c for preventing toner from leaking through the gap between the developing blade 143 and the toner seal 120, and further, the developing sleeve 14 of the developing device casing 104.
The portion 104a along the 0 and the developing blade mounting member 1
A bent portion 104c connected to the portion 104b along the line 44
The portion 120 that projects inward in the longitudinal direction of the developing sleeve
a is provided. Further, a notch 120b is provided at a part of the root of the protrusion 120a as shown in FIG.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIG. The same parts as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the third and fourth embodiments, the seal member 10 is used.
Although the notch portions 101b and 120b of the reference numerals 1 and 120 are provided on the developing blades 141 and 143 side, in this embodiment, FIG.
As shown in (a) and (b), the seal protrusions 101a,
It goes without saying that the same effect can be obtained even if the notches 101b and 120b of the 120a are provided on the developing sleeve 140 side so as to be located near the bent portion 104c of the developing device housing 104.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described with reference to FIGS. FIG. 18 is a schematic configuration diagram of a device according to the sixth embodiment of the present invention. In FIG. 18, reference numeral 202 denotes a developer container containing a non-magnetic toner 206 as a one-component developer, which has an opening extending in the longitudinal direction of the developing device (direction perpendicular to the paper surface). A developing sleeve 203 that rotates in the direction of arrow b in the drawing is provided in the opening as a developer carrying member.
In the opening portion 3, the right half semicircular surface shown in the drawing projects into the developer container 202, and the left substantially semicircular surface is exposed to the developer container 202 and is laterally provided. The surface exposed to the outside of the developer container 202 is arranged so as to face the photoconductor 201, which is a latent image carrier, which rotates in the direction of arrow a, with a slight minute interval, and the surface of the photoconductor 201 is located on the photoconductor 201. The electrostatic latent image is developed and visualized as a toner image.

Further, an elastic blade 204 as an elastic regulating member is provided at an upper position of the developing sleeve 203 in the developer container 202 so as to be inclined downward toward the upstream side in the rotational direction of the developing sleeve 203. The developing sleeve 203 is in contact with the outer peripheral surface of the upper portion of the developing sleeve 203 so as to face in the rotational direction. As a result, the toner 206 carried on the developing sleeve 203 is transferred to the elastic blade 204 and the developing sleeve 203.
The toner 206 that has entered between the contact portions is applied to the developing sleeve 203 to form a thin layer of the toner 206 while rubbing at the contact portion with the frictional charge. And
In the gap between the opening of the container 202 and the developing sleeve 203, an end sealing member 208 made of a felt made of fibers such as Teflon or wool, polyurethane foam, or foam such as rubber sponge is provided. The leakage of the toner 206 from between the sleeves 203 is prevented.

Further, an elastic roller 205 as a developer supplying / separating means is provided at a position upstream of the elastic blade 204 in the rotational direction of the developing sleeve 203. The elastic roller 205 is used as the photosensitive member 20 of the developing sleeve 203.
It is abutted on the portion on the opposite side to 1 and is rotatably supported in the direction of arrow c (that is, in the opposite direction at the abutting portion). The elastic roller 205 carries the toner 206 by its rotation and supplies the toner 206 in the vicinity of the developing sleeve 203.
03 and the elastic roller 205 are in contact with each other at the toner 2
The toner 206 is attached to the developing sleeve 203 by rubbing 06 with the developing sleeve 203.

Below the developing sleeve 203, a lower seal member 207 abuts against the developing sleeve 203 with a slight pressure and abuts against the developing sleeve 203 to prevent the undeveloped toner 206 on the developing sleeve 203 from passing into the container 202. While permitting, the toner 206 is prevented from leaking from the inside of the container 202.

The positional relationship in the longitudinal direction between the lower seal member 207, the opening of the elastic blade 204 and the container 202, and the end seal member 208 provided therein will be described in detail later.

The configuration of each means of the apparatus of this embodiment as described above will be described in detail. First, as the above-mentioned photoconductor 1, for example, a so-called xerographic photoconductor which forms an electrostatic latent image by the Carlson process is disclosed in JP-A-42-2391.
A photoreceptor having an insulating layer on the surface on which an electrostatic latent image is formed by the NP process described in No. 0, an insulator on which an electrostatic latent image is formed by an electrostatic recording method, and an electrostatic latent image is formed by a transfer method. Insulator or other appropriate electrostatic (including potential latent image)
The member forming the is used.

The developing sleeve 203 is made of a material such as aluminum or stainless steel, but a conductive rubber roller may be used. The form is not limited to the cylindrical body (sleeve), and may be an endless belt that is rotationally driven. The developing sleeve 203 in the apparatus of the present exemplary embodiment has an appropriately roughened and roughened surface formed on the surface thereof, thereby increasing the friction probability between the surface of the developing sleeve 203 and the toner 206 and improving the transportability of the toner 206. I am letting you.

Depending on whether the surface of the developing sleeve 203 is sandblasted with irregular-shaped alundum abrasive grains or sandblasted with regular glass beads so that the surface roughness of the uneven surface is 1 to 10 μm. It has gained. Alternatively, a convex rough surface is formed on the surface of the developing sleeve 203 by using conductive particles such as metal oxide particles, graphite, and carbon that can independently form a convex, and the convex rough surface is formed. Phenol resin,
It is also possible to bind with a binding resin such as a fluororesin to form a concave portion on the surface of the binding resin, thereby obtaining a rough surface on the surface of the developing sleeve 203. In this embodiment, as the developing sleeve 203, an aluminum sleeve having a diameter of 16 mm is used as a base, and a glass beads (#
The surface roughness Rz was about 3 μm after blasting according to 600).

Next, regarding the elastic roller 204,
For example, it is formed of a rubber member such as silicone or urethane (having a hardness of 40 ° to 90 ° specified by JISA), a metal plate such as stainless steel or phosphor bronze, or a member obtained by integrally molding rubber on the above metal thin plate, A part of the surface of the elastic blade 204 facing the developing sleeve 203 is in surface contact with the developing sleeve 203, and presses the developing sleeve 203. The contact pressure of the elastic blade 204 to the developing sleeve 203 in the present invention is 5 to 200 in terms of the linear pressure in the generatrix direction of the developing sleeve 203.
g / cm is preferable, and the elastic blade 204 is used in this embodiment.
As the blade, a urethane rubber blade having a hardness of 65 ° and a thickness of 1.2 mm was used, and the blade was brought into contact with the developing sleeve 203 with a linear pressure of 50 g / cm. The linear pressure is measured by stacking three thin plates (for example, stainless steel) having a known coefficient of friction, inserting the elastic blade 203 into the abutting portion, and pulling the center one with a spring scale. The contact pressure was calculated from the friction coefficient.

Further, the elastic roller 205 is composed of a brush in which nylon, rayon or the like is planted from a foam such as polyurethane foam or silicone. The contact width of the elastic roller 205 with the developing sleeve 203 is about 2 to 6 mm.
The peripheral speed is preferably 60 to 200 mm / s as a relative speed between the elastic roller 205 and the developing sleeve 203. In this embodiment, as the elastic roller 205, a roller having a diameter of 6 mm and a polyurethane foam (trade name: malt filter) coated on a core metal having an outer diameter of 14 mm is used, and the contact width with the developing sleeve 203 is 4 mm. The relative speed with respect to the developing sleeve 203 was set to 100 mm / s.

Further, the non-magnetic toner 206 is used as a non-magnetic one-component developer, and is prepared by dispersing a pigment such as carbon in various thermoplastic resins such as styrene resin, acrylic resin, polyethylene resin and the like. There is. In this embodiment, as the toner 206, a toner having a positive polarity in which 1.0% of colloidal silica is externally added to a toner powder having an average particle diameter of 8 μm, which is composed of a copolymer of styrene / acrylic resin and styrene / butadiene and a pigment, is used. I was there.

Next, the longitudinal positional relationship between the lower seal member 207, the elastic blade 204, the opening of the container 202, and the end seal member 208 provided therein will be described in detail.

The lower seal member 207 is made of urethane or PET.
A flexible thin seal such as, for example, is preferable, and in this embodiment, PET (trade name Mylar) having a thickness of 38 μm is used, one end of which is fixed to the lower end of the opening of the developer container 202, and the other end side Is brought into contact with the developing sleeve 203 with a light pressure (a linear pressure of 0 to 5 g / cm in the same manner as the above-mentioned method of measuring the linear pressure of the elastic blade 204) to bring the developing sleeve into contact with the developing sleeve 203. The undeveloped toner 206 on 203 is allowed to pass into the container 202, and the toner 206 is prevented from leaking from the container 202.

Lower seal member 207 and elastic blade 20
4, the opening of the container 202 and the end seal member 208 are positioned in the longitudinal direction, as shown in FIG. 19 which is a view of the developing device viewed from the direction of the drum 201. Longitudinal width i of 204 <lower seal member 2
It is configured to have a longitudinal width j of 07.

In this embodiment, a developing device of A4 width is used, the opening width h of the container 202 is 218 mm, the longitudinal width i of the elastic blade 204 is 221 mm (that is, the contact width 1 with the end seal 208 is 1). 0.5 mm), and the longitudinal width j of the lower seal member 207 is set to 223 mm (that is, the width of contact with the end seal 8 is 2.5 mm).

With this structure, a slight leakage of the toner 206 from the end (E portion) of the elastic blade 204, which occurs when the developing operation is repeated many times in a low humidity environment, gradually develops. When the toner is coated in the form of a stripe (F in FIG. 19) and is sent to the lower portion of the opening of the container 202 as the developing sleeve 203 rotates, the toner 206 acts on the lower seal 207 and the developing sleeve 203 by the action of the lower seal 207. It enters in between (part G in FIG. 19). The toner 206 that has entered between the lower seal 207 and the developing sleeve 203 is an end seal on the downstream side in the rotation direction of the developing sleeve 203 with respect to the contact portion of the lower seal 207 with the developing sleeve 203 as the developing sleeve 203 rotates. The lower seal 207 also seals against the blowout of the toner 206 held in the end seal 208 to the upstream side of the rotation of the developing sleeve 203. Therefore, the toner 2 is not provided on the lower portion of the end seal 208 and the developing sleeve 203 as in the conventional case.
It is possible to prevent the leakage of the toner 206 to the outside of the apparatus at this portion caused by the fixing and gradually depositing 06.

The apparatus as described above was incorporated in a copying machine FC-5 manufactured by Canon Inc., and a bias power supply frequency of 1800 was used.
-2 to AC voltage of Hz, peak-peak voltage 1200V
A photoconductor 20 using a superposed DC voltage of 50V
The surface potential of the electrostatic latent image on No. 1 is dark part −550V, and light part −1.
50 V, the distance between the photoconductor 201 and the developing sleeve 203 was set to 250 μm, and images of 1500 μm were continuously formed in a low temperature and low humidity environment (15 ° C., 10% RH). As a result, the undeveloped toner 206 is allowed to pass through the contact portion of the lower seal member 207 with the developing sleeve 203, and not only the toner 206 leaks out during the developing operation but also the longitudinal end portion of the developing container 202. Toner from 20
It was possible to prevent the leakage of the toner to the outside of the apparatus of 6 and to provide a good image. <Seventh embodiment> Next, a seventh embodiment of the present invention will be described with reference to FIG. Note that the description of the common points with the sixth embodiment will be omitted.

FIG. 20 is a front view of the developing device according to the seventh embodiment of the present invention. In this embodiment, the longitudinal width (k in FIG. 20) of the roughened area of the developing sleeve 203 is set to the container 20.
2 with respect to the opening width h of 2, the length width i of the blade 204, and the length width j of the lower seal member 207, h <i <k <j. The operation of the roughened area k of the developing sleeve 203 determined as described above will be described below.

If the longitudinal width k of the roughened area is set shorter than the longitudinal width i of the blade 204, the blade 20
Both longitudinal end portions of No. 4 come into contact with the smooth surface of the developing sleeve 203 at the sandwiching portion between the developing sleeve 203 and the end seal member 208. Therefore, since a small amount of toner 206 originally exists in the contact portion with the smooth surface, the microscopic contact area between the smooth surface and the surface of the blade 204 is large, and the torque is significantly increased. There may be a case where the surface of the blade 204 at that portion is damaged. Therefore, by making the longitudinal width k of the roughened region longer than the longitudinal width i of the blade 204, the developing sleeve 203 and the end seal member 208 at both longitudinal ends of the blade 204 are provided.
Since the microscopic contact area between the surface of the blade 204 and the surface of the developing sleeve 203 can be reduced in the sandwiching part with the torque increase and damage to the surface of the blade 204 can be prevented.

When the longitudinal width K of the roughened area is made longer than the longitudinal width j of the lower seal member 207, the toner 206 leaking little by little from the L portion in FIG. When entering the developing sleeve 203, since it spreads outward from the longitudinal width j of the lower seal member 207 from both ends of the longitudinal direction of the developing sleeve 203, the end seal member 208 of this portion is formed.
It is scraped off the surface and spills out of the device. Therefore,
By making the longitudinal width k of the roughened region shorter than the longitudinal width j of the lower sealing member 207, it is possible to prevent the toner 206 outside the longitudinal width j of the lower sealing member 207 from spreading and prevent toner leakage. Become.

That is, as described above, by newly defining the roughened area k of the developing sleeve 203 in addition to the sixth embodiment, it becomes possible to enhance the effect of preventing toner leakage.

<Embodiment 8> Next, an embodiment 8 of the invention will be described with reference to FIG. Note that the description of the common points with the sixth embodiment will be omitted.

FIG. 21 shows the shape of the lower seal member 207 according to the eighth embodiment of the present invention. The lower seal member 207 is seen from the direction of the developing sleeve 203 in FIG. The free length of the end portion of the developing sleeve 203 and the end seal 208 sandwiched between the two ends is shorter than the other free lengths. The operation of this structure will be described below.

FIG. 22 shows the shape of the conventional lower seal member 207. With such a structure, the lower seal member 207 abuts against the developing sleeve 203 and abuts both ends thereof. Since it is sandwiched between the developing sleeve 203 and the end seal 208, the contact nip of the lower seal member 207 with respect to the developing sleeve 203 is shown in FIG.
As shown in the O portion of 2, the holding portion has a little expansion. In this state, the developing sleeve 203
Direction (b direction in FIG. 18), the force received by the lower seal member 207 in the sandwiching portion in the q direction becomes larger than the force received in the r direction on the inner side in the longitudinal direction. There is a case where distortion occurs and the cost becomes low, and the toner leaks due to the waving of the lower seal member 207. Therefore, in order to weaken the force received in the q direction described above, in this embodiment, the free length of the lower seal member 207 at both ends in the longitudinal direction is shortened as shown in FIG. 21 (FIGS. 21 a to 21 d). . By doing so, it is possible to reduce the force received by the lower seal member 207 in the s direction due to the rotation of the developing sleeve 203 in the q direction, and the force received in the t direction inside the lower seal member 207 can be made substantially equal to the lower seal member 207. Rippling of 207 can be prevented.

[0081]

As described above, according to the first invention of the present application, in the image forming apparatus using the cartridges containing the different kinds of toner, the process cartridge using the non-magnetic toner is the other process using the magnetic toner. By making the diameter of the developer carrier larger than that of the cartridge and narrowing the distance between the developer carrier and the latent image carrier, it becomes unnecessary to provide the cartridge identification means and the control switching means. Can be reduced.

Further, according to the second aspect of the present invention, since the protruding portion protruding inward in the longitudinal direction of the developing sleeve is provided at the bent portion of the seal member, toner leakage is prevented without increasing the crushing amount of the seal member. Therefore, it is possible to prevent the torque of the developing sleeve from increasing and the assembling property of the developing blade and the like from being deteriorated.

Further, according to the third invention of the present application, in the constitution in which both longitudinal ends of the developing blade and the lower seal are sandwiched between the developing sleeve and the end seal member, the inner wall of the developer container and the longitudinal direction of the developing blade and the lower seal are By setting h <i <j when the widths are set to h, i, and j, respectively, the toner that leaks little by little from both longitudinal ends of the developing blade when the developing operation is repeated is caused by the action of the lower seal. It has become possible to prevent spillage to the outside from being stored inside.

Further, by defining h <i <k <j when the longitudinal width of the roughened area of the developing sleeve is k, it is possible to prevent torque increase and damage at both ends of the developing blade in the longitudinal direction, It was possible to enhance the effect of preventing toner leakage from both ends in the longitudinal direction of the lower portion of the developing sleeve.

Further, by making the free length in the end seal-developing sleeve sandwiching portion at both ends in the longitudinal direction of the lower seal shorter than others, excessive force is applied to the sandwiching portion as the developing sleeve at both ends of the lower seal rotates. It has become possible to prevent this from happening and to eliminate the waving of the lower seal.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a magnetic single-component process cartridge according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of a non-magnetic one-component process cartridge according to Embodiment 1 of the present invention.

FIG. 3 is a sectional view showing a schematic configuration of an image forming apparatus in which the process cartridge of FIGS. 1 and 2 is mounted.

FIG. 4 is a cross-sectional view showing a schematic configuration of a device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a schematic configuration of a third embodiment of the present invention.

FIG. 6 is a partially enlarged view showing a schematic configuration of a developer carrier and an end seal member in the apparatus shown in FIG.

FIG. 7 is a left side view of FIG.

FIG. 8 is a view showing cuts in the end seal member shown in FIG.

FIG. 9 is a diagram showing a schematic configuration of an apparatus of Example 4 of the present invention.

FIG. 10 is a left side view of FIG.

FIG. 11 is a diagram showing cuts in the end seal member shown in FIG. 9.

FIG. 12 is a diagram showing cuts in an end seal member according to a fifth embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a schematic configuration of a conventional device.

14 is a diagram showing a schematic configuration of a developer carrier and an end seal member in the apparatus shown in FIG.

FIG. 15 is a left side view of FIG.

FIG. 16 is a diagram showing a schematic configuration of a conventional apparatus having an elastic developing blade.

FIG. 17 is a left side view of FIG.

FIG. 18 is a cross-sectional view showing the schematic configuration of an apparatus of Example 7 of the present invention.

FIG. 19 is a front view of the apparatus of FIG. 18 viewed from the latent image carrier side.

FIG. 20 is a front view showing a schematic configuration of an eighth embodiment device of the present invention.

FIG. 21 is a front view showing a schematic configuration of a lower sealing member according to Example 9 of the present invention.

FIG. 22 is a front view showing a schematic configuration of a seal member of a conventional device compared with the device of the ninth embodiment.

FIG. 23 is a cross-sectional view showing a schematic configuration of a conventional device that is compared with the seventh to ninth embodiments.

FIG. 24 is a front view of the apparatus of FIG. 23 viewed from the latent image carrier side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Latent image carrier 5 Frame (frame body) 40, 43 Developer carrier 101 Seal member (end seal member) 101a Projection part 104 Toner hopper (developer container) 104a Curved part 104b Straight part 104c Bent part 140 Development Sleeve (developer carrier) 202 Developer container (developer container) 203 Development sleeve (developer carrier) 204 Elastic blade (elasticity control member) 206 Non-magnetic toner (one-component developer) 207 Lower seal member 208 Edge Part seal member

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area G03G 15/09 101

Claims (8)

[Claims] 1. A developer container, a developer bearing member, and a latent image bearing member are integrally provided in a frame body, and different types of developers are accommodated in the developer container and can be attached to and detached from the image forming apparatus. A plurality of process cartridges disposed in the process cartridge, and a voltage applying unit that applies a predetermined voltage between the latent image carrier and the developer carrier in the process cartridge. The cartridge has a magnetic one-component process cartridge containing a magnetic one-component developer and a non-magnetic one-component process cartridge containing a non-magnetic one-component developer, and the non-magnetic one-component process cartridge comprises: The latent image carrier having the same diameter as that of the magnetic one-component process cartridge and the latent image carrier having a diameter larger than that of the magnetic one-component process cartridge are provided. An image having a process cartridge, characterized in that the developer carrying member is set to be short, and the voltage applying means is set to apply a predetermined voltage regardless of the type of the process cartridge. Forming equipment. 2. The developing area in which the developer carrying body is close to the latent image carrying body is set so that the second cartridge is closer to the image exposure section than the developing area in the first cartridge. An image forming apparatus comprising the process cartridge according to claim 1. 3. A developer container having an opening, a cylindrical developer carrier arranged in the longitudinal direction of the opening so that a substantially semi-circular surface is located inside the developer container, and the developer carrier. Adhesion to a straight portion attached to the outer wall surface of the developer container above the developer carrying body at both longitudinal ends of the body and a substantially semi-circular surface located inside the developer container connected from the straight portion. In a developing device having a curved portion curved so as to have a curved portion and an end seal member including a curved portion connecting the curved portion and the straight portion, the developer carrying member length is provided in the curved portion of the end seal member. A developing device, wherein a projecting portion projecting inward in the hand direction is formed. 4. The developing device according to claim 3, wherein a notch is formed at the base of the protruding portion of the end seal member. 5. A developer accommodating container having an opening for accommodating a one-component developer, a rotatable developer carrier disposed in the opening and carrying and carrying the one-component developer, and the developing device. An elastic regulating member, one end of which is attached to the developer accommodating container above the developer carrier and the other end of which is a free end, and which is in contact with the surface of the developer carrier, and below the developer carrier. At one end of the developer carrier, the lower seal member having one end attached to the developer accommodating container and the other end abutting the surface of the developer carrier with the other end free. In a developing device having an end seal member arranged so as to abut both on the peripheral surface of the developer carrier and the inner wall of the developer container, the lower seal member has both longitudinal end portions. It is sandwiched between the end seal and the developer carrier. Its longitudinal width is larger than the longitudinal width of the elastic regulating member, and the longitudinal width of the elastic regulating member is set to be larger than the longitudinal width of the opening. And developing device. 6. The surface of the developer carrying member is roughened, and the longitudinal width of the roughened region is smaller than the longitudinal width of the lower seal member and smaller than the longitudinal width of the elastic restriction member. The developing device according to claim 5, wherein the developing device is set to be large. 7. The lower seal member is formed such that a corner portion of a portion sandwiched between the end seal member and the developer carrying member is formed in an arc shape or is cut out.
The developing device according to 1. 8. The developing device according to claim 5, wherein the one-component developer is a non-magnetic developer.