JPH07160174A - Process cartridge and image forming device - Google Patents

Abstract

PURPOSE:To surely transmit the drive and to prevent the image blur from causing by constructing the device so as to adapt the different transmission system for transmitting the driving force to an image carrier than the system for transmitting the driving force to the other member, such as performing the transmission of the drive force to the image carrier by the coupling means and performing the transmission of the driving force to the other member by the gear. CONSTITUTION:The drum gear 15 is fixed to a longitudinal end of the image carrier by means such as the adhesion, the press fit or the caulking, then the sleeve gear 16 is similarly fixed to an end of the developing sleeve, and both the gear 15 and 16 are mutually engaged with. Namely, the transmission of the driving force from the image carrier to the developing sleeve is performed by the gear. On the other hand, the transmission of the driving force to the image carrier is transmitted from the drive transmission member provided on the device main body by the coupling means. Concretely, by coupling the drum gear 15 of the process cartridge B side with the drive shaft 17 of the image forming device main body side by the coupling means, the drive force transmission between the image forming device and the process cartridge is surely performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge and an image forming apparatus to which the process cartridge can be attached and which forms an image on a recording medium.

[0002]

2. Description of the Related Art In an image forming apparatus such as a printer, a latent image is formed by selectively exposing an image carrier uniformly charged by a charger, and the latent image is developed by a developer by a developer. At the same time as forming an image, the image formed by the developer is transferred to a recording medium to record an image. In such an apparatus, maintenance of each member is performed by a professional service person, which may be inconvenient for the user.

Therefore, the image carrier, the charging device, the developing device,
By integrating the cleaning unit and the like into an integrated structure into a cartridge, the user can replenish the developer and replace the parts of the image carrier that have reached the end of life by loading the cartridge into the main body of the apparatus, facilitating maintenance. What has been done has been put to practical use.

Inside such a process cartridge, there are a photosensitive drum as an image bearing member, a charging roller as a charging device, or a rotating member such as a developing sleeve and a stirring blade inside the developing device. Among them, the charging roller is pressed against the photosensitive drum with a certain pressure so as to be driven to rotate, but the other rotating members are rotated by being given a driving force from the image forming apparatus main body.

For example, as shown in FIG. 9, when the process cartridge 50 is mounted, the drum gear 51 fixed to the photosensitive drum meshes with the drive gear 52 of the apparatus main body, and the drum gear 51 has a sleeve gear 53 fixed to the developing sleeve. Are in mesh. During image formation, the photosensitive drum is rotated by the drive rotation of the drive gear 52, the drive force is transmitted to the sleeve gear 53 and the developing sleeve is rotated, and the drive transmitted to the sleeve gear 53 is further agitated via the gear. The blades are transmitted to drive. That is, all drive transmission was done by gears.

[0006]

However, in the conventional drive transmission system between gears, there is meshing of one tooth and one tooth. Therefore, the impact between the teeth at this time causes load fluctuations, resulting in a gear change. Image blurring of the meshing pitch may appear on the image.

Further, if foreign matter is mixed in the process cartridge and the load is rapidly increased, there is a possibility that tooth jump may occur, especially when the module is small, and tooth damage may occur.

The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is not to provide a process cartridge and an image forming apparatus which are capable of reliable drive transmission and which do not cause image blurring. It is what

[0009]

A typical constitution according to the present invention for achieving the above object comprises an image bearing member and at least one process means acting on the image bearing member. It is characterized in that the driving force transmission to the carrier and the driving force transmission method to members other than the image carrier are different. For example, the driving force is transmitted to the image carrier by a coupling means, and the driving force is transmitted to the other member by a gear.

[0010]

In the above structure, the driving force is transmitted to the image carrier as described above, for example, by the coupling means, so that the occurrence of tooth jumping is eliminated and the reliable drive transmission is performed. Further, by transmitting the driving force to a member other than the image carrier by using, for example, a gear, it is possible to prevent an increase in cost.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, as an embodiment of the present invention, an image forming apparatus in which a process cartridge can be mounted will be specifically described with reference to the drawings.

[First Embodiment] FIG. 1 is a structural explanatory view of an image forming apparatus in which a process cartridge is mounted, FIG. 2 is a structural explanatory view of a process cartridge, and FIG. 3 is an explanatory view of a mounting portion of the process cartridge. Is. Here, as an order of description, the overall configuration of the image forming apparatus in which the process cartridge is mounted will be described, and then the drive transmission configuration of the process cartridge will be described.

{Overall Configuration} This image forming apparatus A is shown in FIG.
As shown in FIG. 3, an optical image based on image information is emitted from the optical system 1 to form an image of a developer (hereinafter referred to as “toner”) on the photosensitive drum that is an image carrier. Then, in synchronism with the formation of the toner image, the recording medium 2 is conveyed from the cassette 3a by a conveying means 3 including a pickup roller 3b, a separation roller 3c, and conveying roller pairs 3d1, 3d2, 3e1, 3e2, and the process cartridge B. In the image forming section formed as a cartridge, the toner image formed on the photosensitive drum is transferred to the recording medium 2 by applying a voltage to the transfer roller 4 serving as a transfer unit, and the recording medium 2 is transferred.
Is conveyed to the fixing means 5 by the guide plate 3f. The fixing means 5 comprises a driving roller 5a and a fixing roller 5c having a heater 5b built therein, and applies heat and pressure to the recording medium 2 passing therethrough to fix the transferred toner image. Then, the recording medium 2 is conveyed by discharge roller pairs 3g1, 3g2 and 3h1, 3h2,
The sheet is discharged to the discharging section 6 through the reverse conveyance path. When the recording medium 2 is manually fed, it is set on the manual feeding tray 3i, and this is put on the pickup roller 3j.
Is carried by the carrying roller pair 3d1, 3d2.

On the other hand, in the process cartridge B forming the image forming section, as shown in FIGS. 1 and 2, the photosensitive drum 7 having a photosensitive layer is rotated, and its surface is transferred to a charging roller 8 which is a charging means. Is uniformly charged by the application of the voltage, and the optical image from the optical system 1 is exposed to the photosensitive drum 7 through the exposure unit 9 to form a latent image, and the latent image is developed by the developing means 10. There is. The developing means 10 feeds the toner in the toner reservoir with a toner feeding member 10a, rotates a developing sleeve 10c having a fixed magnet 10b built therein, and at the same time, a toner layer to which a triboelectric charge is applied by a developing blade 10d is applied to the developing sleeve 10c. By forming the toner on the surface and transferring the toner to the photosensitive drum 7 according to the latent image, a toner image is formed and visualized. Then, after a voltage having a polarity opposite to that of the toner image is applied to the transfer roller 4 to transfer the toner image onto the recording medium 2, the cleaning blade 11a scrapes off the toner remaining on the photosensitive drum 7, and the scooping sheet 11b scoops it. take,
The residual toner on the photosensitive drum 7 is removed by the cleaning means 11 which collects in the waste toner reservoir 11c. Each component such as the photosensitive drum 7 is housed in a housing 12 in which a first frame body 12a and a second frame body 12b are combined to form a cartridge, and a cartridge mounting means provided in a main body 13 of the apparatus. In contrast, it is detachably attached.

In the cartridge mounting means, when the opening / closing member 14 is opened around the shaft 14a, a cartridge mounting space is provided in the apparatus main body 13 as shown in FIG.
A cartridge mounting guide member G1 is attached to the left and right inner surfaces (FIG. 3 shows the guide member on one side).
A guide portion G2 for inserting the process cartridge B is provided opposite to the left and right guide members G1. By inserting the process cartridge B along the guide portion G2 and closing the opening / closing member 14,
Is mounted on the image forming apparatus A.

{Drive Transmission Structure} Next, a drive force transmission structure to each member of the process cartridge B will be described with reference to FIGS. 4 and 5. 4 is a side view of the process cartridge B as seen from the drive section, and FIG. 5 is a vertical sectional view of the vicinity of the photosensitive drum.

A gear (hereinafter referred to as "drum gear") 15 is fixed to one end of the photosensitive drum 7 in the longitudinal direction by adhesion, press-fitting or caulking. A gear (hereinafter referred to as "sleeve gear") 16 is similarly fixed to one end of the developing sleeve 10c, and both gears 15 and 16 mesh with each other. That is, the transmission of the driving force from the photosensitive drum 7 to the developing sleeve 10c is performed by a gear, and when the photosensitive drum 7 rotates during image formation, the driving force is transmitted to the developing sleeve 10c and the sleeve 10c rotates. ..

On the other hand, the transmission of the driving force to the photosensitive drum 7 is configured to be transmitted from the drive transmission member provided in the apparatus main body 13 by the coupling means. Specifically, as shown in FIGS. 4 and 5, the drum gear 15 is provided with a hole 15a at the center thereof, and the hole 15a is provided with engaging recesses 15b at a plurality of positions. In this drum gear 15, as shown in FIG. 5, the shaft portion 15c has a bearing portion 12b1 of the second frame 12b.
When the process cartridge B is rotatably supported by the image forming apparatus A, the bearing portion 12b1 is positioned by the positioning portion 13a of the apparatus body 13.

A drive shaft 17 which is connected to a motor (not shown) and is driven to rotate is provided on the apparatus body 13 side, and a locking projection 17a is integrally provided at an end of the drive shaft 17. There is. The drive shaft 17 is moved by a moving mechanism (not shown) (for example, an electric method or a mechanical method such as a ball screw).
When the process cartridge B is attached to the image forming apparatus A, the drive shaft 17 moves in the direction of arrow a to move the hole portion of the drum gear 15.
The locking projection 17a is inserted into the locking recess 15b and is engaged with the locking recess 15b. On the other hand, when the process cartridge B is removed from the image forming apparatus A, the drive shaft 17 moves in the direction of the arrow b and comes out of the gear hole 15a.

As described above, by connecting the drum gear 15 on the process cartridge B side and the drive shaft 17 on the image forming apparatus A side by the coupling means, the driving force is transmitted between the image forming apparatus A and the process cartridge B. It is possible to perform surely, and it is possible to perform clear image formation without image blurring.

Second Embodiment Next, as a second embodiment, another example of the coupling means for the drum gear and the drive member on the image forming apparatus side will be described with reference to FIG. The same members as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

A shaft portion 18a of the drum gear 18 is projected, and a locking projection 18b is formed on the ridgeline of the tip end of the shaft portion 18a. On the other hand, a motor (not shown) is provided on the device body 13 side.
There is provided a coupling receiving portion 19 which is connected to and is driven to rotate, and the shaft portion 18a can be inserted into the receiving portion 19 and the locking projection 18b can be locked. Further, the receiving portion 19 is configured to be movable in the directions of arrows c and d in FIG. 6 by a moving mechanism (not shown) as in the first embodiment, and when the process cartridge B is attached to the image forming apparatus A. , The receiving portion 19 moves in the direction of arrow c to couple with the shaft portion 18a of the drum gear 15, and the locking projection 18
b engages with the receiving portion 19. On the other hand, when removing the process cartridge B from the image forming apparatus A, the receiving portion 19
Is moved in the direction of arrow d to release the coupling with the shaft portion 18a.

With this structure, the amount of movement of the receiving portion 19 at the time of coupling is smaller than the amount of movement of the drive shaft 17 of the first embodiment, and the device can be downsized. When coupling is performed during image formation, the time from the start of driving the device to the start of rotation of the photosensitive drum 7 is shortened, and the first printing time can be shortened.

Third Embodiment Next, as a third embodiment, another example of the coupling means for the drum gear and the drive member on the image forming apparatus side will be described with reference to FIGS. 7 and 8. Here, FIG. 7 is a view showing a state where the drive shaft on the image forming apparatus side is being coupled to the drum gear, and FIG. 8 is a state after being coupled. The same members as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment described above, the image forming apparatus A
When the drive shaft 17 on the side is coupled to the drum gear 15, the locking projection 17a may not be inserted properly unless the locking recess 15b is in phase. In this embodiment, this point is solved.

As shown in FIG. 7, a drum gear 20 is fixed to one end of the photosensitive drum 7 in the longitudinal direction.
Inside the 20 is a joint member 22 biased by a biasing spring 21.
Is mounted so that it can move in the radial direction of the gear 20 and cannot be removed. Further, a regulating member is provided inside the photosensitive drum 7.
23 is movably mounted in the longitudinal direction of the drum 7, and is biased to the right side in FIG. 7 by a biasing spring 24.

In the state before the drive shaft 25, which will be described later, is coupled, the regulating member 23 presses the joint member 22 by the urging force of the urging spring 24, as shown in FIG.
The movement of the drive shaft 25 in the radial direction of the gear 20 is restricted so that the drive shaft 25 can be inserted into the hole 20a of the drum gear 20.

On the other hand, on the image forming apparatus A side, a drive shaft 25 which can be driven and rotated in cooperation with a motor (not shown) is shown in FIG. 7B.
It is provided so as to be movable in the directions of arrows e and f. Then, as shown in FIG. 7A, the joint member is attached to the drive shaft 25.
There is provided a groove 25a in which 22 can be locked.

In the above structure, the coupling between the drum gear 20 and the drive shaft 25 is as shown in FIG. 7 (b).
The drive shaft 25 is moved in the direction of arrow e with respect to the process cartridge B mounted on the image forming apparatus A, and the drive shaft 25 is inserted into the hole 20a of the drum gear 20.

That is, at the beginning of insertion, the joint member 22 is the regulating member 23.
The drive shaft 25 has a hole
Inserted smoothly into 20a. When the drive shaft 25 is continuously inserted, as shown in FIG. 8B, the drive shaft 25 pushes the regulating member 23 leftward in the drawing, and the regulating member 23 is disengaged from the joint member 22. As a result, the joint member 22 is biased by the spring 21, and its tip is pressed against the drive shaft 25. Normally, in this state, the positions of the groove portion 25a and the joint member 22 are deviated from each other, so that the drive shaft 25 rotates idly even when it is rotated. However, the phase of the joint member 22 and the groove portion 25a coincide with each other within one rotation of the drive shaft 25, and the joint member 22 enters the groove portion 25a as shown in FIG. Will rotate together. In this way, the coupling is completed.

On the other hand, in the case of releasing the coupling, when the drive shaft 25 is moved in the direction of arrow f in FIG. 7 (b), the regulating member 23 moves accordingly and the taper portion 23a is formed.
Contacts the tapered portion 22a of the joint member 22. Then, when the driving member 25 is separated from the regulating member 23, the regulating member 23 becomes a spring.
The urging force of 24 further penetrates into the hole 20a, and the joint member 22
Pushes up and returns to the state before protruding.

With this structure, it is possible to prevent the coupling failure between the drive shaft and the drum gear due to the phase shift.

The same effect can be obtained by providing the joint member 22 on the drive shaft side and the groove 25a on the drum gear 20 side.

[Other Embodiments] In the above-described embodiments, the driving member on the image forming apparatus A side and the drum gear on the process cartridge B side are drivingly connected by the coupling means,
The photoconductor drum 7 and the developing sleeve 10c are drivingly connected by a gear, but the driving member on the image forming apparatus A side and the developing sleeve on the process cartridge B side are drivingly connected by the coupling means described above, and the developing sleeve moves to the photosensitive member. The driving force may be transmitted to the drum by a gear.

Further, the process cartridge B according to the present invention
Not only when forming a single color image as described above,
By providing a plurality of developing means, a multi-color image (for example, a two-color image,
It can also be suitably applied to a cartridge that forms a three-color image or full-color image.

The image bearing member is not limited to the above-mentioned photosensitive drum, but includes, for example, the following. First, a photoconductor is used as the photoconductor, and as the photoconductor, for example, amorphous silicon, amorphous selenium,
Zinc oxide, titanium oxide, organic photoconductor (OPC) and the like are included. The shape on which the photoconductor is mounted includes, for example, a drum-shaped, belt-shaped rotating body, a sheet-shaped body, and the like. Generally, a drum-shaped or belt-shaped one is used. For example, in the case of a drum type photoconductor, a photoconductor is vapor-deposited or coated on a cylinder of aluminum alloy or the like. Is.

As the developing method, various known developing methods such as a two-component magnetic brush developing method, a cascade developing method, a touchdown developing method and a cloud developing method can be used.

As for the structure of the charging means, the so-called contact charging method was used in the above-mentioned first embodiment, but a tungsten wire which has been conventionally used as another structure is provided with metal shields such as aluminum around the three sides, It goes without saying that a configuration may be used in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum to uniformly charge the surface of the drum.

The charging means may be of a blade type (charging blade), a pad type, a block type, a rod type, a wire type or the like other than the roller type.

Further, as a method for cleaning the toner remaining on the photosensitive drum, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

The above-mentioned process cartridge is
For example, an electrophotographic photosensitive member as an image carrier and at least one process means are provided. Therefore, as the mode of the process cartridge, in addition to the embodiment described above, for example, the image carrier and the charging means are integrally made into a cartridge, which can be attached to and detached from the apparatus main body. The image carrier and the developing means are integrally formed into a cartridge, which can be attached to and detached from the main body of the apparatus. The image carrier and the cleaning means are integrally made into a cartridge so that it can be attached to and detached from the apparatus main body. Further, there is one in which an image carrier and two or more of the above-mentioned process means are combined into an integrated cartridge, which can be attached to and detached from the apparatus main body.

That is, the above-mentioned process cartridge is one in which the charging means, the developing means or the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. . Further, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge so that it can be attached to and detached from the main body of the image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be attachable to and detachable from the apparatus main body.

Further, although the laser beam printer has been illustrated as the image forming apparatus in the above-mentioned embodiments, the present invention is not limited to this, and other image forming apparatuses such as an electrophotographic copying machine, a facsimile machine, a word processor and the like can be used. It is also possible to use for.

[0044]

As described above, according to the present invention, when the process cartridge is mounted on the image forming apparatus to form an image as described above, the driving force is transmitted to the image carrier by, for example, the coupling means. By doing so, it is possible to eliminate the occurrence of tooth skipping and to perform reliable drive transmission, and it is possible to prevent cost increases by transmitting drive force to members other than the image carrier, for example, using gears. Is.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view of an image forming apparatus equipped with a process cartridge according to an exemplary embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a process cartridge.

FIG. 3 is a configuration explanatory view of a mounting portion of a process cartridge.

FIG. 4 is an explanatory view of the driving unit as seen from a side view of the process cartridge according to the first embodiment.

FIG. 5 is a vertical sectional view of the vicinity of a photosensitive drum.

FIG. 6 is a vertical cross-sectional view around a photosensitive drum according to a second embodiment.

FIG. 7 is a structural explanatory view of a coupling means according to a third embodiment.

FIG. 8 is a structural explanatory view of a coupling means according to a third embodiment.

FIG. 9 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 A ... Image forming apparatus B ... Process cartridge 1 ... Optical system 2 ... Recording medium 3 ... Conveying means 4 ... Transfer roller 5 ... Fixing means 6 ... Ejecting section 7 ... Photosensitive drum 10 ... Developing means 11 ... Cleaning means 12 ... Housing 13 … Device body 15… Drum gear 16… Sleeve gear 17… Drive shaft 18… Drum gear 19… Coupling receiving part 20… Drum gear 22… Joint member 23… Regulator member 25… Drive shaft

Claims (9)

[Claims] 1. A process cartridge mountable to a main body of an image forming apparatus, comprising: an image bearing member; and a process unit acting on the image bearing member, the driving force transmission to the image bearing member, and the image A process cartridge characterized in that a method of transmitting a driving force to members other than a carrier is different. 2. The process cartridge according to claim 1, wherein the driving force is transmitted to the image carrier by a coupling means, and the driving force is transmitted to the other member by a gear. 3. The process cartridge comprises a charging means, a developing means or a cleaning means as the process means, and an electrophotographic photosensitive member as the image carrier, which are integrally formed into a cartridge, and the cartridge is formed in the main body of the image forming apparatus. The process cartridge according to claim 1, wherein the process cartridge is removable. 4. The process cartridge is an image forming apparatus in which at least one of a charging unit, a developing unit, and a cleaning unit as the process unit and an electrophotographic photosensitive member as the image carrier are integrally formed into a cartridge. The process cartridge according to claim 1, wherein the process cartridge is removable from the main body. 5. The process cartridge is configured such that at least a developing unit as the process unit and an electrophotographic photosensitive member as the image carrier are integrally made into a cartridge so as to be attachable to and detachable from the main body of the image forming apparatus. The process cartridge according to claim 1, which is a product. 6. An image forming apparatus capable of mounting a process cartridge and forming an image on a recording medium, comprising: an image bearing member; and a process unit acting on the image bearing member. Mounting means for mounting a process cartridge configured so that the driving force transmission and the driving force transmission method from the image carrier to other members are different,
An image forming apparatus comprising: a drive transmission unit for transmitting a driving force to the process cartridge; and a transport unit for transporting the recording medium. 7. The image forming apparatus according to claim 6, wherein the image forming apparatus is an electrophotographic copying machine. 8. The image forming apparatus according to claim 6, wherein the image forming apparatus is a laser beam printer. 9. The image forming apparatus according to claim 6, wherein the image forming apparatus is a facsimile apparatus.