JP2022046342A - Positioning members, process cartridges, and image forming devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time and labor related to maintenance and replacement.
SOLUTION: This is a positioning member that determines the facing distance H between a photoconductor drum 11 (first rotating body) and a developing roller 13a (second rotating body), and is a drum shaft 11a (fitted portion) of the photoconductor drum 11. ) Is rotatably fitted to the hole 40a (fitting portion), and the shaft portion 13a10 of the developing roller 13a is slidable so as to extend in a predetermined direction from the opening 40b1 to the abutting portion 40b2. A groove portion 40b is provided. Then, a restricting member 45 that restricts movement in a predetermined direction is detachably installed with respect to the shaft portion 13a10 in a state of being abutted against the abutting portion 40b2 in the groove portion 40b.
[Selection diagram] FIG. 4

Description

The present invention is an image of a positioning member that determines the facing distance between two rotating bodies, a process cartridge that is detachably installed with respect to the main body of an image forming apparatus, a copying machine, a printer, a facsimile, or a combination machine thereof. It relates to a forming device.

Conventionally, in a process cartridge installed in an image forming apparatus such as a copying machine or a printer, the gap (opposing distance) between the developing roller (developer carrier) and the photoconductor drum (image carrier) is set with high accuracy. For that purpose, a technique for providing a face plate (positioning member) for fitting the shaft portion of the developing roller and the shaft portion of the photoconductor drum is known (see, for example, Patent Document 1 and the like).

Specifically, the face plate (positioning member) in Patent Document 1 and the like is formed with a hole portion that fits into the shaft portion of the developing roller of the developing apparatus and a hole portion that fits into the shaft portion of the photoconductor drum. .. Then, by fitting the shaft portion of the developing roller and the shaft portion of the photoconductor drum into the two holes of the face plate, the distance between the shafts of the developing roller and the photoconductor drum is determined, and the developing roller and the photoconductor are formed. The gap with the drum is set with high accuracy.

In the conventional process cartridge, when the developer carrier (second rotating body) is maintained or replaced, after removing a plurality of screws for fixing the positioning member (face plate) to the process cartridge, the process cartridge is removed from the process cartridge. The positioning member had to be removed to separate the image carrier (first rotating body) and the developing device from the positioning member. Therefore, it takes time and effort to maintain and replace the developer carrier.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a positioning member, a process cartridge, and an image forming apparatus, which can reduce the time and labor involved in maintenance and replacement.

The positioning member in the present invention is a positioning member that determines the facing distance between the first rotating body and the second rotating body, and is a fitting portion in which the fitted portion of the first rotating body is rotatably fitted. A state in which the shaft portion of the second rotating body is provided with a groove portion that is formed in a groove shape so as to extend from the opening portion to the abutting portion in a predetermined direction and the shaft portion of the second rotating body can slide and move, and the groove portion abuts against the abutting portion. A restricting member that restricts movement in the predetermined direction is detachably installed on the shaft portion of the above.

According to the present invention, it is possible to provide a positioning member, a process cartridge, and an image forming apparatus that reduce the time and labor involved in maintenance and replacement.

It is an overall block diagram which shows the image forming apparatus in embodiment of this invention. It is a block diagram which shows the image-making part. It is sectional drawing which shows the main part of the process cartridge in the longitudinal direction. It is a figure which shows the state which the developing apparatus is attached to the process cartridge. It is a figure which shows the state which the developing apparatus was removed from a process cartridge. (A) A schematic view showing a state in which the developing device is mounted on the face plate of the process cartridge, and (B) a schematic view showing a state in which the developing device is removed from the face plate of the process cartridge. It is an enlarged view which shows the positioning member in the process cartridge as a modification 1. FIG. It is an enlarged view which shows the positioning member in the process cartridge as the modification 2. It is a top view which shows the main part of the positioning member of FIG. Is.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the duplicated description thereof will be appropriately simplified or omitted.

First, FIG. 1 describes the overall configuration and operation of the image forming apparatus 1.
In FIG. 1, 1 is a color copier as an image forming apparatus, 3 is a document conveying unit that conveys a document to a document reading unit 4, 4 is a document reading unit that reads image information of a document, and 6 is based on input image information. A writing unit (exposure unit) that emits laser light is shown.
Further, 7 is a paper feed device for storing a sheet P such as paper, 10Y, 10M, 10C, and 10BK are process cartridges as an image forming unit corresponding to each color (yellow, magenta, cyan, black), and 17 is a plurality of colors. An intermediate transfer belt on which the toner images of the above are transferred in an overlapping manner, and 18 is a secondary transfer roller for transferring the toner image formed on the intermediate transfer belt 17 to the sheet P.
Further, 20 is a fixing device for fixing an unfixed image on the sheet P, 28 is a toner container for supplying toner of each color to the developing devices of each process cartridge 10Y, 10M, 10C, and 10BK, and 30 is collecting waste toner. The waste toner collection container, which is to be used, is shown.

Here, each process cartridge 10Y, 10M, 10C, and 10BK (image-creating unit) is an integrated body of a photoconductor drum 11 as an image carrier, a charging device 12, a developing device 13, and a cleaning device 15, respectively. Yes (see Figure 2). Then, each process cartridge 10Y, 10M, 10C, 10BK is replaced with a new one when it reaches the end of its life.
Toner images of each color (yellow, magenta, cyan, black) are formed on the photoconductor drum 11 (image carrier) in each process cartridge 10Y, 10M, 10C, and 10BK.

Hereinafter, the operation of a normal color image forming apparatus in the image forming apparatus will be described.
First, the original is conveyed from the platen by the transfer roller of the original transfer unit 3 and placed on the contact glass of the original reading unit 4. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass.
Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 6. Then, the laser beam (exposure light) based on the image information of each color is emitted from the writing unit 6 toward the photoconductor drum 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK, respectively.

On the other hand, the four photoconductor drums 11 are rotated clockwise in FIGS. 1 and 2, respectively. Then, referring to FIG. 2, first, the surface of the photoconductor drum 11 is uniformly charged at the position facing the charging device 12 (charging roller) (the charging step). In this way, a charging potential is formed on the photoconductor drum 11. After that, the surface of the charged photoconductor drum 11 reaches the irradiation position of each laser beam.
In the writing unit 6, the laser beam L corresponding to the image signal is emitted from the light source corresponding to each color. The laser beam L is incident on the polygon mirror, reflected, and then transmitted through the plurality of lenses. The laser beam after passing through the plurality of lenses passes through different optical paths for each of the yellow, magenta, cyan, and black color components (exposure step).

The laser beam corresponding to the yellow component irradiates the surface of the photoconductor drum 11 of the first process cartridge 10Y from the left side of the paper surface. In this way, an electrostatic latent image corresponding to the yellow component is formed on the photoconductor drum 11 after being charged by the charging roller 12a.
Similarly, the cyan component laser beam is applied to the surface of the photoconductor drum 11 of the process cartridge 10C second from the left on the paper surface to form an electrostatic latent image of the cyan component. The laser beam corresponding to the magenta component is applied to the surface of the photoconductor drum 11 of the process cartridge 10M, which is the third from the left on the paper surface, to form an electrostatic latent image corresponding to the magenta component. The laser beam of the black component is applied to the surface of the photoconductor drum 11 of the process cartridge 10BK, which is the fourth from the left on the paper surface, to form an electrostatic latent image of the black component.

After that, the surface of the photoconductor drum 11 on which the electrostatic latent image of each color is formed reaches a position facing the developing device 13 (see FIG. 2). Then, toners of each color are supplied from each developing device 13 onto the photoconductor drum 11 to develop a latent image on the photoconductor drum 11 (a developing step).
After that, the surface of the photoconductor drum 11 after the developing step reaches a position facing the intermediate transfer belt 17 (intermediate transfer body) as an image carrier, respectively. Here, at each facing position, a primary transfer roller 14 is installed so as to abut on the inner peripheral surface of the intermediate transfer belt 17. Then, at the position of the primary transfer roller 14, the toner images of each color formed on the photoconductor drum 11 are sequentially superimposed and transferred onto the intermediate transfer belt 17 (the primary transfer step).

Then, the surface of the photoconductor drum 11 after the primary transfer step reaches a position facing the cleaning device 15 (see FIG. 2), respectively. Then, the cleaning device 15 recovers the untransferred toner remaining on the photoconductor drum 11 (cleaning step). The untransferred toner collected in the cleaning device 15 is conveyed in the transfer pipe 16 by the transfer screw 15b (see FIG. 2), and is collected as waste toner in the waste toner collection container 30.
After that, the surface of the photoconductor drum 11 passes through the position of the static elimination device, and a series of image forming processes in the photoconductor drum 11 is completed.

On the other hand, the surface of the intermediate transfer belt 17 on which the images of each color on the photoconductor drum 11 are superimposed and transferred travels in the direction of the arrow in FIG. 1 and reaches the position of the secondary transfer roller 18. Then, at the position of the secondary transfer roller 18, the full-color image on the intermediate transfer belt 17 is secondarily transferred onto the sheet P (this is the secondary transfer step).
After that, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning device 9 (cleaning device). Then, the untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning device 9, and a series of transfer processes on the intermediate transfer belt 17 is completed. The untransferred toner collected in the intermediate transfer belt cleaning device 9 is conveyed in the transfer pipe 16 by the transfer screw 15b (see FIG. 2), and is collected as waste toner in the waste toner collection container 30.

Here, the sheet P at the position of the secondary transfer roller 18 is conveyed from the paper feeding device 7 via the transfer guide, the resist roller 19, and the like.
Specifically, the sheet P fed by the paper feed roller 8 is guided to the resist roller 19 from the paper feed device 7 that houses the sheet P after passing through the transport guide. The sheet P that has reached the resist roller 19 is conveyed toward the position of the secondary transfer roller 18 in time with the toner image on the intermediate transfer belt 17.

After that, the sheet P to which the full-color image is transferred is guided to the fixing device 20. In the fixing device 20, the color image is fixed on the sheet P by the nip of the fixing roller and the pressure roller.
Then, the sheet P after the fixing step is ejected as an output image to the outside of the apparatus main body 1 by the paper ejection roller 29, and then is stacked on the paper ejection unit 5, and a series of image forming processes is completed.

Next, in FIGS. 2 and 3, the image forming portion of the image forming apparatus will be described in detail.
FIG. 2 is a configuration diagram showing a black process cartridge 10BK. The other three process cartridges 10Y, 10M, and 10C are configured to be almost the same as the black process cartridge 10BK except that the colors of the toners used in the image forming process are different from each other. And are omitted.

As shown in FIG. 2, the process cartridge 10BK mainly includes a photoconductor drum 11 as an image carrier, a developing device 13, a charging device 12, and a cleaning device 15 in a cartridge case 50 (housing). It is stored integrally.
The cleaning device 15 is provided with a cleaning blade 15a and a transport screw 15b that come into contact with the photoconductor drum 11.

The developing apparatus 13 mainly includes a developing roller 13a as a developing agent carrier forming a developing region facing the photoconductor drum 11, a first transport screw 13b1 (first transport member) facing the developing roller 13a, and a partition member. The second transport screw 13b2 (second transport member) facing the first transport screw 13b1 via 13e, and the doctor blade 13c (2) that regulates the amount of the developer carried on the developing roller 13a facing the developing roller 13a. Developer control member), etc.

A developer (two-component developer) composed of toner and a carrier is housed in the developing apparatus 13.
The developing roller 13a is configured to form a developing region facing the photoconductor drum 11 with a minute gap H (see FIG. 3). As shown in FIG. 3, the developing roller 13a is composed of a magnet 13a1 which is fixed inside and forms a plurality of poles (magnetic poles) on the outer peripheral surface of the roller, and a sleeve 13a2 which rotates around the magnet 13a1. Ru.

The transport screws 13b1 and 13b2 as transport members transport the developer contained in the developing apparatus 13 in the longitudinal direction to form a circulation path (the circulation path indicated by the broken line arrow in FIG. 3). That is, a circulation path for the developer is formed by the first transport path B1 by the first transport screw 13b1 and the second transport path B2 by the second transport screw 13b2.
The first transport path B1 and the second transport path B2 are separated by a partition member 13e (wall portion), and both ends of the two transport paths B1 and B2 in the longitudinal direction communicate with each other via communication ports 13f and 13g. ing. Specifically, with reference to FIG. 3, an end portion of the first transport path B1 on the upstream side in the transport direction and an end portion of the second transport path B2 on the downstream side in the transport direction are connected via the first communication port 13f. Communicate. Further, the end portion of the first transport path B1 on the downstream side in the transport direction and the end portion of the second transport path B2 on the upstream side in the transport direction communicate with each other via the second communication port 13 g. That is, the partition member 13e is arranged at a position excluding both ends in the longitudinal direction.
The first transport screw 13b1 (first transport path B1) is arranged so as to face the developing roller 13a, and the second transport screw 13b2 (second transport path B2) is connected to the first transport screw 13b1 (1st transport path B2) via the partition member 13e. It is arranged so as to face the first transport path B1). The first transport screw 13b1 supplies the developer toward the developing roller 13a while transporting the developer in the longitudinal direction, and collects the developer separated from the developing roller 13a after the developing step. The second transport screw 13b2 stirs and mixes the developer after the developing process transported from the first transport path B1 and the fresh developer replenished from the toner supply port 13d while transporting them in the longitudinal direction.
In the present embodiment, the two transport screws 13b1 and 13b2 (transport members) are arranged side by side in the horizontal direction. In each of the two transport screws 13b1 and 13b2, a screw portion is wound around a shaft portion.

The image formation process described above will be described in more detail with a focus on the development process.
The developing roller 13a rotates in the direction of the arrow in FIG. As shown in FIG. 3, the developer in the developing device 13 is a toner container by rotating the first transport screw 13b1 and the second transport screw 13b2 arranged so as to interpose the partition member 13e in the direction of the arrow. It circulates in the longitudinal direction while being stirred and mixed together with the toner replenished from the toner replenishment port 13d (inflow port) from 70 via the toner replenishment path 27 (circulation in the direction of the broken arrow arrow in FIG. 3).
The toner replenishment port 13d of the developing device 13 is linked to and disconnected from the toner replenishing path 27 of the image forming apparatus main body 1 in conjunction with the attachment / detachment operation of the developing device 13 (process cartridge 10BK) to the image forming apparatus main body 1. Will be.

Then, the toner that is triboelectrically charged and adsorbed on the carrier is pumped onto the developing roller 13a together with the carrier by the agent pumping electrode formed on the developing roller 13a. The developer carried on the developing roller 13a is conveyed in the direction of the arrow in FIG. 2 and reaches a position facing the doctor blade 13c. Then, the developer on the developing roller 13a is conveyed to a position facing the photoconductor drum 11 (a developing region) after the amount of the developer is adjusted appropriately at this position. Then, the toner is adsorbed on the latent image formed on the photoconductor drum 11 by the electric field formed in the developing region. After that, the developer remaining on the developing roller 13a reaches above the first transport path B1 as the sleeve rotates, and is separated from the developing roller 13a at this position. Here, the electric field in the developing region is a predetermined voltage (development bias) applied to the developing roller 13a by the power supply for developing, and a surface potential (development bias) formed on the surface of the photoconductor drum 11 by the charging step and the exposure step. It is formed by the latent image potential).

The toner in the toner container 70 is appropriately replenished into the developing device 13 from the toner replenishing port 13d as the toner in the developing device 13 is consumed. The consumption of toner in the developing device 13 is detected by a toner concentration sensor that magnetically detects the toner concentration of the developing agent in the developing device 13 (the ratio of the toner in the developing agent).
Further, the toner supply port 13d is provided on one end side of the second transport screw 13b2 in the longitudinal direction (the left-right direction in FIG. 3) and above the second transport screw 13b2 (second transport path B2). ing.

Hereinafter, the face plate 40 as a positioning member, which is characteristic of the process cartridge 10BK in the present embodiment, will be described in detail with reference to FIGS. 3 to 6 and the like.
As described above with reference to FIGS. 2, 3 and the like, the process cartridge 10BK is a unit that is detachably installed with respect to the image forming apparatus main body 1. The process cartridge 10BK includes a photoconductor drum 11 (first rotating body) as a rotatable image carrier and a developing roller 13a (second rotating body) as a rotatable developer carrier facing the photoconductor drum 11. Rotating body) etc. are installed.
The developing roller 13a (developer carrier) is rotatably held by the developing apparatus 13. Further, the developing apparatus 13 is configured to accommodate the developing agent inside, and is detachably installed with respect to the process cartridge 10BK.

Here, referring to FIGS. 3 and 4, the process cartridge 10BK in the present embodiment has a face plate 40 as a positioning member that determines the facing distance H (development gap) between the photoconductor drum 11 and the developing roller 13a. (First face plate) is detachably installed on one end side (left side in FIG. 3) in the rotation axis direction (longitudinal direction).
Further, in the process cartridge 10BK, a face plate 41 (second face plate) as a second positioning member that determines the facing distance H (development gap) between the photoconductor drum 11 and the developing roller 13a is provided on the other end side (second face plate) in the rotation axis direction. It is detachably installed on the right side of FIG. 3).

As described above, in the process cartridge 10BK in the present embodiment, the face plates 40 and 41 are installed at both ends in the rotation axis direction, respectively. First, the face plates as positioning members installed on one end side in the rotation axis direction. 40 (first face plate) will be described.
The face plate 40 functions as a positioning member that determines the facing distance H between the photoconductor drum 11 as the first rotating body and the developing roller 13a as the second rotating body.

As shown in FIGS. 4 and 5, the face plate 40 (positioning member) is formed with a hole portion 40a as a fitting portion and a notch-shaped groove portion 40b.
The hole portion 40a functions as a fitting portion in which the drum shaft 11a as a fitted portion of the photoconductor drum 11 (first rotating body) as an image carrier is rotatably fitted. The hole portion 40a is formed so that the hole diameter thereof is substantially the same as the shaft diameter of the drum shaft 11a.
The groove portion 40b is formed in a groove shape so as to extend from the opening portion 40b1 (one end side) to the abutting portion 40b2 (the other end side) in a predetermined direction (the direction in which the virtual line S1 in FIG. 4 extends). The shaft portion 13a10 of the developing roller 13a (developer carrier) as the second rotating body is configured to be slidable. The groove portion 40b is formed so that the groove width thereof substantially matches the shaft diameter of the shaft portion 13a10. Further, the abutting portion 40b2 of the groove portion 40b has an arcuate surface portion having substantially the same diameter as the shaft diameter (outer diameter) of the shaft portion 13a10. Further, the center of the arcuate abutting portion 40b2 is formed so as to pass through the virtual line S1 in which the center lines of the two surface portions facing each other so as to sandwich the shaft portion 13a10 in the groove portion 40b are extended in the direction in which the groove portion 40b extends. ing.
In the present embodiment, the direction in which the groove portion 40b extends (“predetermined direction”) is the center of the hole portion 40a (the center of the drum shaft 11a) as the fitting portion and the center of the abutting portion 40b2 (the shaft portion 13a10). The direction in which the virtual line S1 passing through the center) extends.

Then, referring to FIGS. 4 and 5, the face plate 40 (positioning member) in the present embodiment is inserted from the opening 40b1 in the groove 40b with respect to the shaft portion 13a10 in a state of being abutted against the abutting portion 40b2. Therefore, a restricting member 45 that restricts movement in a predetermined direction (the direction in which the virtual line S1 extends) is detachably installed.
Specifically, the limiting member 45 is a substantially rectangular parallelepiped member made of a resin material, and a snap fit is formed at the tip portion thereof, and the limiting member 45 is detachably fitted into the groove portion 40b. Then, as shown in FIG. 4, the limiting member 45 is fitted into the groove portion 40b, and the position of the shaft portion 13a10 in the groove portion 40b is determined so that the shaft portion 13a10 (development roller 13a) does not fall off from the groove portion 40b. Further, as shown in FIG. 5, the limiting member 45 is taken out from the groove portion 40b so that the shaft portion 13a10 can be slidably moved in the groove portion 40b.
In the present embodiment, a snap fit is formed on the limiting member 45 and the limiting member 45 is detachably installed on the face plate 40. However, the method of installing the limiting member 45 is not limited to this, and the limiting member 45 is fastened with screws, for example. It can also be detachably installed on the face plate 40.

With the face plate 40 configured in this way, the position of the photoconductor drum 11 (drum shaft 11a) is determined by the hole portion 40a, and the position of the developing roller 13a (shaft portion 13a10) is determined by the groove portion 40b. In particular, the developing roller 13a is held by the limiting member 45 so that the shaft portion 13a10 is in close contact with the abutting portion 40b2. As a result, the distance between the axes of the photoconductor drum 11 and the developing roller 13a is determined, and the developing gap H (see FIG. 3) is set to the target value with high accuracy.
In particular, when the developer carried on the developing roller 13a comes into contact with the photoconductor drum 11, even if the developing roller 13a receives pressure (reaction force) from the developing agent, the developing gap H does not change, which is good. Development process will be performed.

Further, in the present embodiment, the groove portion 40b of the face plate 40 is provided with an opening 40b1 that opens diagonally to the lower left in FIG. 5 so that the shaft portion 13a10 can be inserted into and removed from the groove portion 40b.
That is, in the groove portion 40b, the abutting portion 40b2 is formed with a curved wall portion (consisting of an inner peripheral surface having substantially the same diameter as the outer peripheral surface of the shaft portion 13a10) to which the outer peripheral surface of the shaft portion 13a10 abuts. On the other hand, in the groove portion 40b, the opening portion 40b1 is not formed with a wall portion on which the shaft portion 13a10 abuts, and is opened diagonally downward with the groove width of the groove portion 40b. As a result, the shaft portion 13a10 can be moved in the direction of the arrow in FIG. 5 to separate from the groove portion 40b, or the shaft portion 13a10 can be moved in the opposite direction to be inserted into the groove portion 40b. Further, the shaft portion 13a10 can be moved (sliding) along the groove portion 40b.

By forming the groove portion 40b on the face plate 40 in this way, the time and labor related to the maintenance and replacement of the developing roller 13a can be reduced as compared with the case where the groove portion for positioning is formed instead of the groove portion 40b. Become.
Specifically, when the developing roller 13a (developer 13) is maintained or replaced, the photoconductor drum 11 is fitted without taking time and effort to release the fitting between the photoconductor drum 11 and the face plate 40. The developing roller 13a (developing device 13) can be attached to and detached from the face plate 40 in the state of being in the state of being processed.
In particular, in the present embodiment, in order to improve the detachability of the developing roller 13a (developing device 13) with respect to the process cartridge 10BK, the groove portion 40b connects the center of the virtual line S1 (the center of the drum shaft 11a and the center of the shaft portion 13a10). The virtual line) is formed along the extending direction. Therefore, when the operator performing maintenance removes the developing device 13, the developing device 13 is moved in a direction away from the photoconductor drum 11, so that it is possible to prevent the developing device 13 from damaging the photoconductor drum 11. Further, even when the operator attaches the developing device 13, by bringing the developing device 13 straight to the photoconductor drum 11, attention is paid to the positional relationship between the photoconductor drum 11 and the developing device 13, which is not possible. Careful attention suppresses the problem of damaging the photoconductor drum 11.

Here, with reference to FIGS. 3 and 4, in the present embodiment, the face plate 40 as a positioning member is detachably coupled to the developing case 13r of the developing apparatus 13 and the cartridge case 50, respectively (this embodiment). In the form of, it is screw-fastened.)
The cartridge case 50 is a housing of the process cartridge 10BK different from the developing case 13r, and holds the photoconductor drum 11 as well as the charging device 12 and the cleaning device 15. In addition to the developing roller 13a, the developing case 13r holds two transport screws 13b1 and 13b2 and a doctor blade 13c.

Specifically, the face plate 40 is formed with three screw holes into which the screws 60 can be inserted. Further, one female screw portion is formed on the side surface of the developing case 13r, and two female screw portions are formed on the side surface of the cartridge case 50.
Then, the screw 60 is screwed into one female screw portion of the developing case 13r through the screw hole portion of the face plate 40, and the screw 60 is screwed into each of the two female screw portions of the cartridge case 50. As a result, as shown in FIGS. 3 and 4, in the process cartridge 10BK, the developing apparatus 13 is joined via the face plate 40 and integrated as one unit. Further, the face plate 40 determines the distance between the axes of the photoconductor drum 11 and the developing roller 13a, and the developing gap H (see FIG. 3) is set to a target value with high accuracy.

Here, the developing apparatus 13 collides with the shaft portion 13a10 of the developing roller 13a with the opening 40b1 in a state where the face plate 40 is released from the developing case 13r (a state in which one screw 60 is removed). It is formed to be detachably formed together with the developing roller 13a with respect to the face plate 40 in a state of being connected to the cartridge case 50 (a state in which two screws 60 are screwed) by being moved to and from the portion 40b2. ..

Specifically, as shown in FIG. 4, in order to perform maintenance or replacement of the developing device 13, the developing device 13 is removed from the process cartridge 10BK to which the developing device 13 is connected by the screw 60 via the face plate 40. In this case, first, the process cartridge 10BK is taken out from the image forming apparatus main body 1.
Then, as shown in FIG. 5, in the taken-out process cartridge 10BK, the screw 60 for connecting the developing device 13 (one is installed on each of the two face plates 40 and 41 at both ends) is removed. At this time, the photoconductor drum 11 is still connected to the cartridge case 50 by the face plate 40 by the screw 60. Further, as shown in FIG. 5, the limiting member 45 is removed from the face plate 40.
Then, as shown in FIG. 5, the developing apparatus 13 in a state where the screw fastening with the face plate 40 (the limiting member 45 is removed) is released is moved diagonally downward along the groove portion 40b of the face plate 40. Then, the developing device 13 is removed from the process cartridge 10BK. Specifically, the shaft portion 13a10 of the developing roller 13a is moved diagonally downward along the groove portion 40b, and the developing device 13 is removed from the process cartridge 10BK. At this time, in the process cartridge 10BK, the constituent members (photoreceptor drum 11, charging device 12, cleaning device 15) other than the developing device 13 remain held in the cartridge case 50.
When the developing device 13 is attached to the process cartridge 10BK, the operation is performed in the reverse procedure of the above-mentioned withdrawal procedure.

By forming the groove portion 40b in the face plate 40 in this way, the time and labor related to the maintenance and replacement of the developing apparatus 13 can be reduced as compared with the case where the groove portion for positioning is formed instead of the groove portion 40b. become.
Specifically, when performing maintenance or replacement of the developing device 13, it takes time and effort to release the fitting between the photoconductor drum 11 and the face plate 40 with respect to the face plate 40 in which the photoconductor drum 11 is fitted. The developing device 13 can be attached to and detached from the face plate 40 without hanging.

In addition, referring to FIG. 3, one of the two face plates 40 and 41 (the first face plate on the left side in FIG. 3) is a non-rotating shaft portion 13a10 (magnet) in the developing roller 13a. It is a shaft portion for determining the posture of 13a1 in the rotation direction.). On the other hand, the other face plate 41 (the second face plate on the right side in FIG. 3) has a rotatable shaft portion 13a20 (a shaft portion for rotating the sleeve 13a2) in the developing roller 13a. It is for holding.

Then, in the present embodiment, the face plate 41 as the second face plate is not formed with the groove portion 40b like the face plate 40 (positioning member) as the first face plate, but the second positioning without the groove portion 40b. It is configured as a member.
For details, with reference to FIGS. 3 and 6, the face plate 41 (second face plate) as the second positioning member is formed with a hole portion 41a as a fitting portion and a positioning hole portion 41b. The hole portion 41a as the fitting portion is rotatably fitted with the drum shaft 11a (fitted portion) of the photoconductor drum 11 in the same manner as that of the first face plate 40. On the other hand, in the positioning hole portion 41b, the shaft portion 13a20 of the developing roller 13a (developer carrier) is fitted via a detachable bearing 65 (in this embodiment, a ball bearing). do. That is, the second face plate 41 is formed with a positioning hole portion 41b instead of the groove portion 40b of the first face plate 40.

With this configuration, as shown in FIGS. 6A and 6B, the bearing 65 mounted on the second face plate 41 is removed in the direction of the arrow to remove the shaft portion on the other end side of the developing roller 13a. A large gap is formed between the 13a20 and the positioning hole portion 41b, the positioning of the developing device 13 by the second face plate 41 is released, and the developing device 13 can be moved up, down, left and right to some extent.
Therefore, as described above with reference to FIG. 5, when the developing device 13 is removed from the process cartridge 10BK while moving the developing roller 13a along the groove portion 40b of the first face plate 40, the second face plate 41 and the developing device are used. By releasing the screw fastening with 13 and disconnecting the bearing 65, the second face plate 41 can be left attached to the process cartridge 10BK. Specifically, while moving the developing device 13 in the direction of the rotation axis or diagonally downward with the bearing 65 detached, the developing device 13a is moved along the groove portion 40b of the first face plate 40 from the process cartridge 10BK. 13 will be removed.
By forming the second face plate 41 in this way, the time and labor involved in the maintenance and replacement of the developing apparatus 13 can be reduced. Specifically, when the developing device 13 is maintained or replaced, the photoconductor drum 11 and the two face plates 40, 41 are fitted to the two face plates 40, 41 in which the photoconductor drum 11 is fitted. The developing device 13 can be attached to and detached from the two face plates 40 and 41 without taking time and effort to release the mating.

In this embodiment, as shown in FIG. 6, a hole is formed in the second face plate 41 (second positioning member) from the positioning hole portion 41b toward one end side in the rotation axis direction (the left side in FIG. 6). A mortar-shaped hole portion 41c (tapered portion) whose diameter gradually increases is formed.
As a result, when the bearing 65 is removed from the second face plate 41, the movable range of the developing roller 13a (shaft portion 13a20) is further expanded. Therefore, the developing apparatus with the above-mentioned face plates 40 and 41 mounted on the process cartridge 10BK. The attachment / detachment of 13 becomes easy.

<Modification 1>
As shown in FIG. 7, in the face plate 40 (first face plate) as the positioning member in the modification 1, the shape of the abutting portion 40b2 of the groove portion 40b is different from that shown in FIGS. 4 and 5.
Specifically, in the face plate 40 shown in FIG. 7A, the abutting portion 40b2 of the groove portion 40b has a surface portion formed in an arc shape centered on the rotation center in the hole portion 40a (fitting portion). There is. That is, the abutting portion 40b2 is formed in a convex curved surface shape on the side of the opening portion 40b1.
With this configuration, there is a gap (play) between the groove portion 40b (two surface portions facing each other across the shaft portion 13a10) and the shaft portion 13a10, and the position of the shaft portion 13a10 that abuts on the abutting portion 40b2. Even if the distance between the drum shaft 11a (photoreceptor drum 11) and the shaft portion 13a10 (development roller 13a) does not vary, the development gap H (see FIG. 3) is aimed at. The value will be set accurately.
Further, the face plate 40 shown in FIG. 7B has two face portions in which the abutting portion 40b2 of the groove portion 40b gradually decreases the facing distance from each other toward the hole portion 40a (fitting portion) side. ing. That is, the abutting portion 40b2 is formed in a concave shape in a substantially "<" shape on the side of the opening portion 40b1.
With this configuration, the shaft portion 13a10 is abutted even when a gap (play) is provided between the groove portion 40b (two surface portions facing each other across the shaft portion 13a10) and the shaft portion 13a10. Since the position can be determined by abutting against the portion 40b2, the distance between the axes of the photoconductor drum 11 and the developing roller 13a is determined, and the developing gap H (see FIG. 3) is set to the target value with high accuracy. Become.

<Modification 2>
As shown in FIG. 8, on the face plate 40 in the second modification, the shaft portion 13a10 is urged toward the drum shaft 11a (fitted portion) as a limiting member for limiting the movement of the shaft portion 13a10 in the groove portion 40b. A leaf spring member 46 is used as the elastic member.
The leaf spring member 46 (restricting member) as an elastic member is a metal plate having a substantially L-shape and having conductivity and springiness.
On the other hand, referring to FIGS. 8 and 9, the face plate 40 is formed with an insertion hole portion 40e, a fixing portion 40f, a flat surface portion 40d, and the like. The insertion hole portion 40e is a hole portion in which the pressing portion 46b (the portion excluding the bending portion 46a) of the leaf spring member 46 is inserted so as to be elastically deformable and intersects and communicates with the groove portion 40b. The fixing portion 40f is a portion in which the tip end portion of the pressing portion 46b of the leaf spring member 46 that has passed through the groove portion 40b is inserted and fixed. The flat surface portion 40d is a portion where the bent portion 46a of the leaf spring member 46 is abutted against the surface contact.
In the leaf spring member 46, when the shaft portion 13a10 does not exist in the abutting portion 40b2 (it is in a state where it is not elastically deformed), the shaft portion 13a10 is scheduled to be installed as shown by the broken line in FIG. It will enter the range (within the range of the outer diameter of the shaft portion 13a10). Then, with the shaft portion 13a10 installed on the abutting portion 40b2, the leaf spring member 46 is elastically deformed as shown by the solid line in FIG. 5, and the shaft portion 13a10 (development roller 13a) is moved to the side of the photoconductor drum 11. Will be urged to.
As a result, the shaft portion 13a10 abuts against the abutting portion 40b2 so that the distance between the shafts of the photoconductor drum 11 and the developing roller 13a is determined, and the developing gap H (see FIG. 3) is accurately set to the target value. It will be set.
In particular, in the leaf spring member 46 in the second modification, the bent portion 46a is fixed by the flat surface portion 40d, and the tip portion of the pressing portion 46b is removably inserted by the fixed portion 40f, so that the pressing portion with respect to the shaft portion 13a10 is inserted. It becomes easier to secure the urging force of 46b. Therefore, the effect of the above-mentioned shaft portion 13a10 abutting against the abutting portion 40b2 is likely to be exhibited.

Here, referring to FIG. 8, in the process cartridge 10BK in the second modification, a development bias is applied to the shaft portion 13a10 of the developing roller 13a via the leaf spring member 46 (restricting member) of the face plate 40 (positioning member). It is configured as follows.
Specifically, the leaf spring member 46 is a power supply 90 installed in the image forming apparatus main body 1 in conjunction with an operation in which the developing apparatus 13 (process cartridge 10BK) in which the face plate 40 is installed is attached to and detached from the image forming apparatus main body 1. It is configured to be electrically connected / disconnected. Then, in a state where the developing device 13 (process cartridge 10BK) is mounted on the image forming apparatus main body 1, in the normal image forming process, as described above with reference to FIG. 2, the leaf spring member 46 is removed from the power supply 90. A predetermined development bias is applied to the development roller 13a via the development roller 13a, and the development process is performed.
By making the leaf spring member 46 also function as an electrode for applying a development bias in this way, the device can be made smaller and less costly as compared with the case where such an electrode is installed exclusively. ..
As shown in FIG. 8, in the leaf spring member 46 in the modified example 2, a convex portion 46b1 that can make point contact with the shaft portion 13a10 located at the abutting portion 40b2 is formed in the pressing portion 46b. In this way, by configuring the pressing portion 46b (convex portion 46b1) to make point contact with the shaft portion 13a10, the shaft portion 13a10 is configured as compared with the case where the pressing portion 46b is configured to make surface contact with the shaft portion 13a10. Since the contact state of the pressing portion 46b with respect to the developing roller 13a is likely to be stabilized, the application of the developing bias to the developing roller 13a is also stabilized.
Further, the shaft portion 13a10 in the modification 2 is non-rotating as described above, but when the shaft portion 13a10 is configured to rotate, the pressing portion 46b (convex portion 46b1) is pointed to the shaft portion 13a10. By configuring the pressing portion 46b to be in contact with the shaft portion 13a10, the sliding resistance of the pressing portion 46b due to the sliding contact with the shaft portion 13a10 can be reduced as compared with the case where the pressing portion 46b is configured to be in surface contact with the shaft portion 13a10. ..
In addition, referring to FIGS. 9A and 9B, it is formed in the insertion port 40e1 of the face plate 40 (the opening for inserting the pressing portion 46b of the leaf spring member 46 into the insertion hole portion 40e). The convex portion 40e10 is for preventing the convex portion 46b1 from interfering with the leaf spring member 46 when the leaf spring member 46 is attached to the face plate 40.

As described above, the face plate 40 in the present embodiment is a positioning member that determines the facing distance H between the photoconductor drum 11 (first rotating body) and the developing roller 13a (second rotating body), and is a photoconductor. A hole 40a (fitting portion) into which the drum shaft 11a (fitted portion) of the drum 11 is rotatably fitted is formed in a groove shape so as to extend in a predetermined direction from the opening 40b1 to the abutting portion 40b2. A groove portion 40b is provided so that the shaft portion 13a10 of the developing roller 13a can be slidably moved. Then, a restricting member 45 that restricts movement in a predetermined direction is detachably installed with respect to the shaft portion 13a10 in a state of being abutted against the abutting portion 40b2 in the groove portion 40b.
This reduces the time and effort involved in maintenance and replacement.

In the present embodiment, the hole portion 40a as the fitting portion of the face plate 40 (positioning member) is fitted to the drum shaft 11a as the fitted portion of the photoconductor drum 11 (image carrier). Configured. However, the combination of the fitted portion of the image carrier and the fitting portion of the positioning member is not limited to this, and for example, the concave flange as the fitted portion of the photoconductor drum 11 (image carrier) can be used. It is also possible to configure the convex member as the fitting portion of the face plate 40 (positioning member) to fit.
Further, in the present embodiment, the hole portion 40a and the groove portion 40b in the face plate 40 are formed so as to penetrate the drum shaft 11a and the shaft portions 13a10 and 13a20, respectively. On the other hand, at least one of the hole portion 40a and the groove portion 40b in the face plate 40 is formed so that the drum shaft 11a and the shaft portions 13a10 and 13a20 do not penetrate and the outside in the rotation axis direction is closed. You can also do it.
Further, in the present embodiment, the groove portion 40b is formed along the direction in which the virtual line S1 (the virtual line connecting the center of the drum shaft 11a and the center of the shaft portion 13a10) extends, but the direction in which the groove portion 40b extends. Is not limited to this. Further, in the present embodiment, the groove portion 40b is formed so as to extend in an oblique direction, but the direction in which the groove portion 40b extends is not limited to this, and the opening portion 40b1 is arranged so as to face the photoconductor drum 11. It suffices if it does not exist, and for example, the groove portion 40b can be formed so as to extend in the horizontal direction.
And even in such a case, the same effect as that of this embodiment can be obtained.

Further, in the present embodiment, the present invention is applied only to the face plate 40 (first face plate) installed on one end side of the process cartridge 10BK, and to the face plate 41 (second face plate) installed on the other end side. The present invention (groove portion 40b and limiting member 45) was not applied. However, the positioning member (face plate 40) according to the present invention may be detachably installed at least on one end side in the rotation axis direction, and the face plate installed on the other end side also has the present invention (groove portion 40b or limiting member 45). ) Can be applied. In that case, the positioning members (face plates 40) of the present invention installed at both ends in the rotation axis direction are symmetrical with respect to the rotation axis direction.
Further, in the present embodiment, the present invention has been applied to a positioning member (face plate 40) that determines the facing distance H between the photoconductor drum 11 as the first rotating body and the developing roller 13a as the second rotating body. The application of the present invention is not limited to this, and the present invention can be applied to all of the positioning members that determine the facing distance between the first rotating body and the second rotating body.
And even in such a case, the same effect as that of this embodiment can be obtained.

Further, in the present embodiment, the present invention is applied to the process cartridge 10BK including the photoconductor drum 11 (image carrier), the developing device 13, the charging device 12, and the cleaning device 15, but the present invention is applied. The process cartridge is not limited to this, and the present invention can be applied as long as at least a photoconductor drum (image carrier) and a developing device (developer carrier) are installed.
And even in such a case, the same effect as that of the present embodiment can be obtained.
In the present application, the "process cartridge" includes a charging device for charging the image carrier, a developing device for developing a latent image formed on the image carrier, and a cleaning device for cleaning the image carrier. It is defined as a unit in which at least one of them and an image carrier are integrated and configured to be detachably attached to the image forming apparatus main body.

The positioning of the shaft portion of the developing roller 13a described so far is the positioning of the developing roller 13a in the process cartridge 10BK, and corresponds to the main reference of the developing device 13. On the other hand, the secondary reference (positioning of the developing roller 13a with respect to the rotation direction) can be formed on at least one of the one end side and the other end side of the cartridge case 50 or the face plates 40 and 41. When the main reference of the face plates 40 and 41 is formed in the groove, it is desirable that the secondary reference is formed in the groove in the same manner as the face plates 40 and 41.
In particular, by forming the groove portion of the reference standard parallel to the groove portion of the face plate, the risk of damaging the photoconductor drum 11 when the developing device 13 is attached / detached can be significantly reduced.
On the other hand, when a portion inclined with respect to the groove portions of the face plates 40 and 41 is provided in at least a part of the groove portion of the reference standard, a portion where the developing apparatus 13 does not come off smoothly is provided and the limiting member is removed. The developing apparatus 13 may be configured so as not to easily fall off from the process cartridge 10BK.
Particularly desirable is to form the groove portion of the reference plate so as to be parallel to the groove portions of the face plates 40 and 41 in a predetermined range on the photoconductor drum side (the back side in the attachment / detachment direction of the developing device 13) from the photoconductor drum 11. It is preferable to provide an inclined portion on a part of the remote side (the front side in the attachment / detachment direction of the developing device 13).
This makes it possible to prevent the developing device 13 from falling off from the process cartridge 10BK while separating the developing device 13 from the photoconductor drum 11 without damaging the photoconductor drum 11.

It is clear that the present invention is not limited to the present embodiment, and the present embodiment may be appropriately modified in addition to the suggestions in the present embodiment within the scope of the technical idea of the present invention. be. Further, the number, position, shape and the like of the constituent members are not limited to the present embodiment, and the number, position, shape and the like suitable for carrying out the present invention can be used.

1 Image forming apparatus (image forming apparatus main body),
10Y, 10M, 10C, 10BK process cartridge,
11 Photoreceptor drum (first rotating body, image carrier),
11a Drum shaft (fitted part),
13 developing equipment,
13a Developing roller (second rotating body, developer carrier),
13a10, 13a20 shaft part,
13r developing case,
40 face plate (positioning member, first face plate),
40a hole (fitting part),
40b groove,
40b1 opening, 40b2 abutment,
40d flat surface part, 40e insertion hole part, 40f fixed part,
41 Face plate (second positioning member, second face plate),
41a hole (fitting part), 41b positioning hole,
41c mortar-shaped hole,
45 limiting member,
46 Leaf spring member (restriction member),
46a Bent part,
46b Pressing part,
46b1 convex part,
50 cartridge case,
60 screws,
65 bearings,
H Development gap (opposite distance),
S1 virtual line.

Japanese Patent No. 6202387

Claims (13)

A positioning member that determines the facing distance between the first rotating body and the second rotating body.
A fitting portion in which the fitted portion of the first rotating body is rotatably fitted, and a fitting portion.
A groove portion formed in a groove shape so as to extend from the opening portion to the abutment portion in a predetermined direction, and a shaft portion of the second rotating body can be slidably moved.
Equipped with
A positioning member characterized in that a limiting member for restricting movement in a predetermined direction is detachably installed with respect to the shaft portion in a state of being abutted against the abutting portion in the groove portion. The positioning member according to claim 1, wherein the abutment portion of the groove portion is provided with an arcuate surface portion having substantially the same diameter as the outer diameter of the shaft portion. The positioning member according to claim 1, wherein the abutment portion of the groove portion includes a surface portion formed in an arc shape centered on a rotation center in the fitting portion. The positioning member according to claim 1, wherein the abutment portion of the groove portion includes two surface portions whose facing distances gradually decrease toward the fitting portion side. The positioning member according to any one of claims 1 to 4, wherein the predetermined direction is a direction in which a virtual line passing through the center of the fitting portion and the center of the abutting portion extends. The positioning member according to any one of claims 1 to 5, wherein the limiting member is an elastic member that urges the shaft portion toward the fitted portion. The elastic member is a leaf spring member formed in a substantially L shape.
The pressing portion excluding the bent portion of the leaf spring member is inserted so as to be elastically deformable, and the insertion hole portion that intersects and communicates with the groove portion and the insertion hole portion.
A fixing portion into which the tip end portion of the pressing portion of the leaf spring member that has passed through the groove portion is inserted and fixed, and a fixing portion.
A flat surface portion to which the bent portion of the leaf spring member is abutted so as to be able to make surface contact,
The positioning member according to claim 6, wherein the positioning member is provided with. The positioning member according to claim 6 or 7, wherein the leaf spring member is provided with a convex portion capable of making point contact with the shaft portion located at the abutting portion. It is a process cartridge that is detachably installed with respect to the main body of the image forming apparatus.
The image carrier as the first rotating body and the image carrier
A developing device in which the developer carrier as the second rotating body is rotatably held and is detachably installed with respect to the process cartridge,
Equipped with
A process cartridge according to any one of claims 1 to 8, wherein the positioning member is detachably installed on at least one end side in the rotation axis direction. The positioning member according to any one of claims 1 to 8 is installed on one end side in the rotation axis direction.
A second positioning member that determines the facing distance between the image carrier and the developer carrier is detachably installed on the other end side in the rotation axis direction.
The second positioning member is
A fitting portion in which the fitted portion of the image carrier is rotatably fitted, and a fitting portion.
The shaft portion of the developer carrier is fitted with a positioning hole portion via a removable bearing.
9. The process cartridge according to claim 9. The process cartridge according to claim 10, wherein the second positioning member includes a mortar-shaped hole whose hole diameter gradually increases from the positioning hole toward one end in the rotation axis direction. The process cartridge according to any one of claims 9 to 11, wherein a development bias is applied to the shaft portion of the developer carrier via the limiting member of the positioning member. An image forming apparatus according to any one of claims 1 to 8, wherein the positioning member according to any one of claims 1 to 8 or the process cartridge according to any one of claims 9 to 12 is detachably installed.

Images