JPS62170978A - Process cartridge - Google Patents

Abstract

PURPOSE:To reduce the running cost of a cartridge to be consumed and to supply inexpensively copies to users by leaving a photosensitive drum on the device body side and replacing other image forming means as a cartridge. CONSTITUTION:The image forming means such as a developing device 5, a cleaning means 14 and an electrifier 4 excluding the photosensitive drum 3 are stored in one enclosure to constitute a process cartridge 30 and respective units in the cartridge 30 are simultaneously replaced. To load/unload the process cartridge 30 to/from the device body, the cartridge 30 is moved along the rails 31, 32 of the copying machine body side in the rotary shaft direction of the drum 3. The cartridge 30 is provided with four mechanism, i.e. a flaw preventing mechanism for preventing the drum 3 from being flawed at the loading/ unloading, a toner leakage preventing mechanism for preventing toner leakage from the developing unit and the cleaner at the loading/unloading and storage, a positioning mechanism on the device body and the drum 3, and a driving mechanism for the drum 3 and a developing sleeve.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention [Field of Industrial Application] The present invention relates to a process cartridge applied to an image forming apparatus such as an electrophotographic copying machine, an electrostatic recording machine, or a printer.

[Conventional technology]

Some conventional process cartridges of this type are configured such that a photoreceptor, a developing device, a cleaning device, a charger, and the like are housed in one housing to form a cartridge that can be attached to and detached from the main body of an image forming apparatus.

[Problem that the invention seeks to solve]

The lifespan of the process cartridge described above is determined by the following times: when the toner in the developing device is used up, when the photosensitive drum deteriorates, when cleaning is inadequate, when the charger becomes dirty and abnormal discharge occurs, etc. If this occurred at any time, the entire cartridge would have to be replaced as a consumable item, resulting in high running costs.

However, in recent years, with the advent of A-5i (amorphous silicon) photoreceptors, the photoreceptor has a long lifespan, and the lifespan of the main body of the device is approaching its end.

The present invention has been proposed with attention to this point, and the photosensitive drum is left in the main body of the apparatus, and the other image forming means is made into a cartridge, and when the toner is used up, it is replaced when another failure occurs. This method reduces the running cost of the cartridge, which is a consumable item, making it possible to supply copies to users at a low cost, and also prevents scratches on the photosensitive drum surface when the process cartridge is installed and removed. The purpose is to

Summary: Structure of the Invention [Means for Solving Problems] The present invention includes an image bearing member attached to an apparatus main body, and some of the constituent units used for image formation located near the image bearing member housed in a housing. In the process cartridge configured to be removably attached to the apparatus main body, an abutting member moves the component unit housed in the casing away from the image carrier in conjunction with the operation of attaching and detaching the casing to the apparatus main body. The process cartridge is characterized in that the component unit is provided with:

[For production]

The image bearing member remains in the apparatus main body, and the image forming means around it is made into a cartridge which can be attached to and removed from the apparatus main body, and the image forming means is moved away from the image bearing member in conjunction with this attachment and detachment operation. There is no risk of damaging the image carrier due to contact with the image forming means during attachment and detachment. In addition, the cost of the cartridge, which is a consumable item, is reduced, and the lighter weight of the cartridge improves operability.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The drawings illustrate an electrophotographic copying machine, and FIGS. 1 to 3 are diagrams illustrating the structure of the electrophotographic copying machine. Note that Figure 2 is the same as Figure 1.
FIG. 3 is a diagram showing the state in which the top of the main body of the copying machine is opened, and FIG. 3 is the same diagram with the process cartridge removed.

In the figure, reference numeral 1 denotes a document tray made of a transparent member, which moves back and forth in the direction of the arrow. Reference numeral 2 denotes an imaging element array, which slit-exposes the optical image of the original image on the original table L onto the A-9i photosensitive drum 3 serving as an image carrier. In addition, the photosensitive drum 3
rotates in the direction of the arrow about the shaft 3a as a fulcrum. 4 is a corona charger, which charges the photosensitive drum 3 uniformly; 5 is a developer, which converts the electrostatic latent image formed by exposing the uniformly charged photosensitive drum to light using the array 2 into toner; Develop it with

On the other hand, the transfer sheet P is fed onto the surface of the photosensitive drum 3 by a feeding roller 6 and a register roller 7, and the toner image on the photosensitive drum is transferred by a transfer charger 8. Thereafter, the sheet is separated from the drum by the separating means 13, passes over the guide 9, and passes through the roller 9a located at the end of the conveyance path.
is sent to the fixing device 10. The toner image on the sheet is fixed by a fixing device 10, and the sheet is discharged onto a tray 12 by a discharge roller 11. Toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14.

15 is an illumination system for exposing the original, and 16 is a filter such as a heat ray absorption filter.

As shown in FIG. 2, the main body of the copying machine housing each of the above-mentioned constituent units is divided into an upper housing 17 and a lower housing 18, which are connected by a spindle 19, and the upper housing is separated around this spindle 19. 1
7 is configured to rotate upward.

In this upper housing 17, image forming means such as the illumination optical system 2, 15, the photosensitive drum 3, the self-developing means 5, and the cleaning device 14 are arranged.

In the lower housing 18, a feeding roller 6, a transfer charger 8, a separating means 13, a guide 9, a fixing device 10, and the like are arranged on a sheet conveyance path.

Further, in this embodiment, the photosensitive drum 3 of the image forming means
The process cartridge 30 is constructed by housing the developing unit 5, cleaning unit 14, charger 4, and other image forming units in a single housing, and by replacing each unit in the process cartridge 30 at the same time, maintenance is easy. We are trying to reduce the workload.

The process cartridge is attached to and removed from the main body of the apparatus by moving it along the rails 31 and 32 on the side of the main body of the copying machine in the direction of the rotation axis of the photosensitive drum 3 (in the longitudinal direction of the drum). At this time,
The photosensitive drum 3 remains on the upper mounting body 17 as it is.

FIG. 4 is an enlarged sectional view of the process cartridge 30. This process cartridge 30 includes: (1) a mechanism to prevent scratches on the photosensitive drum 3 during attachment/detachment; (2) a mechanism to prevent toner from leaking from the developer and cleaner during attachment/detachment and during storage; (2) a positioning mechanism for the device main body and the photosensitive drum. , ■
It incorporates four mechanisms: a drive mechanism for the photosensitive drum and the developing sleeve.

Therefore, the user can very easily attach and detach the process cartridge 30 to and from the main body of the apparatus, and the process cartridge 30 is characterized in that toner does not scatter even when the user handles it.

Each of the above mechanisms of the process cartridge 30 will be explained in detail below. First, process cartridge 30
A method for preventing the developing sleeves adjacent to the photosensitive drum 3 from coming into contact with each other and causing scratches or nicks when the developing sleeve is attached to and removed from the apparatus main body will be described.

FIG. 4 shows the natural state before the process cartridge 30 is installed in the main body of the apparatus. That is, the developing device 5 is swingably attached to the front and rear side walls of the process cartridge with a rotation shaft 22, and is pressed by a compression spring 24. The developer stopper portion 28 is in contact with the stopper portion 26 of the process cartridge.

On the other hand, like the developing unit 5, the cleaner 4 is also attached to the front and rear side walls of the process cartridge so as to be able to swing freely around a rotating shaft 23, and the cleaner stopper portion 27 is brought into contact with one end 27 of the stopper groove of the process cartridge by a tension spring 25. There is.

5 and 6 show the state in which the process cartridge 30 is being installed in the apparatus main body. When installed, the retraction rib 33 of the developing device 5 is guided by the developing device guide rail surface 31-1 of the right guide rail 31, and the compression spring 2
4 in the compressing direction, and expand the developing device 5 outward around the rotating shaft 22. As a result, the distance between the developing sleeve 104 and the surface of the photosensitive drum 3 becomes wider than in the natural state. This action continues from when the process cartridge 30 starts to be installed in the apparatus main body until just before the installation is completed.
When released from the developing sleeve 1, as shown in FIG.
Rollers 105 and 106 fixed to both ends of the photosensitive drum 3 contact the surface of the photosensitive drum 3, and the photosensitive drum 3 and the developing sleeve 1
04 is maintained at a predetermined distance as shown in FIG.

On the other hand, the cleaner 14 is installed at the same time as the installation is completed.
The release rib 34 is guided by the cleaner guide rail surface 32-2 of the left guide rail 32, rotates around the fixed shaft 23 in the direction of extending the tension spring 25, and moves to a predetermined cleaner position.

That is, as shown in FIG. 6, a cleaning blade 35 made of an elastic material fixed to the cleaner 14 is attached to a scoop sheet arm 36 (always fixed to the process cartridge body and does not rotate) fixed to the fixed shaft 23. When the cleaner 14 moves to a predetermined position as shown in FIG. 9 from the overlapping state inside the pick sheet 37 made of polyester sheet material, the cleaning blade 35 slides inside the pick sheet 37 and touches the surface of the photosensitive drum 3. Move to pressure contact state.

As shown in FIG. 4, the scoop sheet arm 36 and the inner wall 14a of the cleaner main body slide through the scoop sheet 37, and are rotated at R1 and R2, respectively, around the fixed shaft 23 to prevent toner from flowing out. It has a surface. Also,
On both sides of the cleaning blade 35 and the scraper sheet 37, a sealing member 3 made of felt, maltblen, etc. is attached.
8 is attached to the cleaner body 14.

With the above configuration, the process cartridge 30 effectively prevents toner from flowing out from the developing unit 5 and the cleaner 14 not only when it is not installed in the apparatus main body but also during installation and removal from the apparatus main body.

FIGS. 10 to 13 are diagrams showing other examples of means for preventing damage to the photosensitive drum when the process cartridge 30 is attached to and removed from the main body of the apparatus.

As shown in FIG. 10, in the vicinity of the photosensitive column 3,
A roller 202 that is rotatable in the direction of the drum axis is attached, and the point r1 of the roller 202 that is closest to the center of the photosensitive drum 3
is in the relationship r, ≦R with respect to the diameter H of the photosensitive drum 3.

On the other hand, like the developing device 5, the cleaner 4 is also swingably attached to the front and rear side walls of the cartridge body with a rotating shaft 23, and is pressed by a compression spring 25 so that the cleaner stopper portion 29 comes into contact with the stopper 29 of the cartridge. ing.

In addition, at a position close to the photosensitive drum 3 of the cleaner 4,
A rotatable roller 201 is installed, and the roller 201
The point r2 closest to the center of the photosensitive drum 3 has a relationship of r2≦R with respect to the diameter R of the photosensitive drum 3.

The rollers 201 and 202 are connected to the developing unit 5 when the process cartridge 30 is installed in the apparatus main body as shown in FIG. The cleaner 4 is located at a position where it comes into contact with the photosensitive drum 3 before other parts.

FIG. 12 shows the process cartridge 30 being installed in the main body of the apparatus from the direction of arrow A, and FIG. 13 is an enlarged cross-sectional view of the PROYAS cartridge in this installed state.

In the developing device 5, the roller 201 is connected to the end slope portion 3- of the photosensitive drum 3.
1, it is pushed in the direction of arrow a and moves around the fixed shaft 22, and the distance between it and the photosensitive drum 3 becomes wider than in the natural state. This state continues until just before the installation of the cartridge body is completed. When the installation is completed, the roller 201 falls into the retraction flange 3-2 via the end slope portion 3-3.
The developing device stopper 28 of the developing device 5 comes into contact with the stopper 28 of the cartridge, and the distance between the developing device 5 and the photosensitive drum 3 is maintained at a predetermined position.

The cleaner 4 is also moved away from the photosensitive drum 3 in the same manner as the developing device 5 to increase the distance between the surfaces thereof during the mounting operation, and is held at a predetermined position when the mounting is completed.

With the above configuration, in order to form a gap between the photosensitive drum 3, the developing device 5, and the cleaner 14 when the process cartridge is attached/detached, the main body side of the copying machine as shown in the examples of FIGS. There is no need to install a guide rail on the
It can have a simple configuration.

Figure 14 shows the process cartridge 3 shown in Figure 1 above.
FIG. 2 is a vertical cross-sectional view of the device 0 attached to the main body of the device, viewed from above. In this Figure 14.

A mechanism for positioning the process cartridge 30 between the side plate of the upper body 17 and the center of the photosensitive drum 3 will be described.

On the back side of the process cartridge 30, two positioning pins 86 and 87 are provided for the back side plate 81, and on the front side, fitting holes 92 and 93 provided in the front side plate 91 are provided as in the back side.
Pins 88 and 89 are provided which are positioned at. In addition, a positioning pin 9 with respect to the central axis 3a of the photosensitive drum 3 is provided.
One 0 is provided.

That is, although the photosensitive drum 3 is supported in a cantilevered manner on the back side,
At the same time that the process cartridge 30 is installed in the apparatus main body, the positioning pins 90 are fitted into the end surface recesses 3d of the central shaft 3a of the photosensitive drum 3, so that the photosensitive drum 3 is supported at both ends. At the same time, the developing device 5, cleaner 14, and charger (not shown in FIG. 7), which are constituent means of the process cartridge 30,
is arranged at a predetermined position with respect to the photosensitive drum 3.

By installing the process cartridge 30 into the apparatus main body as described above, the process cartridge 30 and the apparatus main body are positioned, and at the same time, the process cartridge 30
By positioning the process cartridge 30 and the photosensitive drum 3, the positional relationship with other parts is ensured only by the process cartridge 30, which makes it easy to attach and detach the process cartridge and improves operability.

Note that the direction in which the process cartridge 30 is attached and removed may be in the circumferential direction of the photosensitive drum 3 in addition to the generatrix direction of the photosensitive drum 3 .

Next, the photosensitive drum 3 and the developing sleeve 1 in the cartridge.
The drive system of 04 will be explained with reference to FIG. The drum shaft 3a of the photosensitive drum 3 is fixed to the back side plate 81 of the apparatus main body,
The photosensitive drum 3 is rotatably mounted via bearing members 94 and 95 provided at both ends of the drum shaft 3a, and a ring 3b is mounted on the tip (front side) of the drum shaft 3a to rotate the photosensitive drum 3 in the thrust direction. Movement is regulated.

On the back side of the photosensitive drum 3, a small-diameter gear 3C is fixed to a drum shaft that protrudes from the drum, and meshes with a drive gear 95 at the end of the shaft that protrudes inside the main body of the apparatus. In response to the drive start command, the drive system (not shown) of the main body of the device activates the drive gear 9.
5 is rotationally driven, the photosensitive drum 3 is rotated through the gear 3C.
Rotate.

On the other hand, an arm 97 that can swing about the same axis is fitted into the tip of a shaft 96 that protrudes inside the main body of the device, and a gear 98 is fixed to the tip.

A gear 100 is attached to the tip of the arm 97 by a shaft 99, and meshes with a gear 98 and a gear lot fixed to the rear end of the developing sleeve 104. Further, the arm 97 is pulled upward by a spring 102 and stops against a stopper 103 protruding from the main body of the apparatus.

When the process cartridge 30 is inserted into the apparatus main body, the photosensitive drum 3 and the developing/imaging sleeve 1 are
Since the sleeve gear 101 and the drive gear 100 are opposed to each other, they do not mesh with each other because the sleeve gear 101 and the drive gear 100 do not mesh with each other when the sleeve gear 101 and the drive gear 100 are completely inserted into a predetermined position.

During this engagement, even if the cartridge is set in such a state that the tips of both teeth are in contact with each other, the pressing force of the developing device unit is maintained by the arm 97 (the third
) rotates counterclockwise to prevent the tips of the teeth from coming into contact with each other. Here, the shaft 96 starts rotating in response to the copy command, and when the gear 98 rotates, it is lifted upward by the spring 102, the driving gear 100 and the developing sleeve gear 101 are engaged, and the developing sleeve 104 is rotated.

FIG. 15 shows an embodiment in which the photosensitive drum 3 and cleaner 14 are left in the main body of the apparatus, and a cartridge in which a developing device 5 and a charger 4 are integrally housed in a housing can be attached to and removed from the main body of the apparatus.

If the toner storage capacity of the cleaner 14 is increased, the replacement cycle of the cleaner will be longer than that of the cartridge, so it can be left in the main body of the apparatus.

In this embodiment, when the process cartridge 3o is attached to and removed from the main body of the apparatus, there is no action to separate the cleaner 14 from the photosensitive drum 3, so there is no toner scattering from the cleaner 14, and therefore a complicated device for preventing toner scattering is not required. becomes.

Similarly, even if a cartridge containing a developer containing multicolor toner is installed and a print operation is performed, the cleaner 14
Image defects due to mixing of toners of different colors that occur when the toner is once removed from the photosensitive drum 3 and then reattached do not occur.

FIG. 16 shows an embodiment in which the photosensitive drum 3 and the developing device 5 are left in the main body of the apparatus, and a cartridge in which the cleaner 14 and the charger 4 are integrally housed in a housing can be attached to and removed from the main body of the apparatus.

Generally, developing devices are complicated and expensive.

Therefore, if you increase the toner capacity of the developing device 5 or replenish the toner in the developing device 5, the replacement cycle of the developing device 5 can be longer than the replacement cycle of the cartridge. can be left in the main body of the apparatus, and the process cartridge 30 can be made small and inexpensive.

FIG. 17 shows an embodiment in which the photosensitive drum 3 and the charger 4 are left in the main body of the apparatus, and a cartridge in which the cleaner 14 and the developer 5 are integrally housed in a housing can be attached to and removed from the main body of the apparatus.

Unlike the cleaner 14 and the developing device 5, the charger 4 is not a consumable item, so it can be left in the main body of the apparatus as a semi-permanent part. Furthermore, since the charging wire is generally contaminated by toner and the cleaning cycle for this does not necessarily coincide with the cartridge replacement cycle, the charging device 4 is left in the main body of the apparatus and the wire of the charging device 4 is cleaned as appropriate.

C. Effects of the Invention As described above, according to the present invention, a photosensitive drum as an image bearing member is provided on the main body side of the apparatus, and when the image forming unit around the photosensitive drum is formed into a cartridge and is attached to and removed from the main body of the apparatus. The image forming unit is moved away from the photosensitive drum in conjunction with the attachment/detachment operation, and is returned to a predetermined position when the device is completed, so that the attachment/detachment operation is easy and damage to the photosensitive drum due to contact with the image forming unit during attachment/detachment is prevented. I can do it.

Furthermore, since the photosensitive drum is provided in the main body of the apparatus and not in the form of a cartridge, the cost of the cartridge, which is a consumable item, is reduced. In other words, the running cost per copy is reduced, which is very advantageous for the user.

By not treating the photosensitive drum as a consumable item, resources can be saved, and problems related to cartridge disposal, such as when a toxic photosensitive agent is used in the photosensitive drum itself, can be solved.

By not incorporating the photosensitive drum into the cartridge, the cartridge is lighter and the user's operability is improved, and even if the user handles the cartridge roughly, the photosensitive drum will not be scratched (conventional cartridges have It was easy to get scratched due to the arrangement of various image forming means.)

When conventional cartridges with a built-in photosensitive drum were left outside the machine for a long time, light could enter through gaps in the housing, causing the photosensitive drum to retain optical memory and resulting in abnormal images. Since there is no built-in light, the above-mentioned phenomenon does not occur, and in other words, there is no need for a light-shielding mechanism in the cartridge.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing an image forming apparatus according to a first embodiment of the present invention, FIG. 2 is a view of the image forming apparatus in an upper open state, and FIG. 3 is the same view with the process cartridge removed. Figure 4 is an enlarged cross-sectional view of the process cartridge, Figure 5 is a bottom view showing the process cartridge being installed in the main body of the device, Figure 6 is an enlarged cross-sectional view of the process cartridge in the middle of installation, and Figure 7 is the process cartridge. FIG. 8 is an enlarged cross-sectional view of the process cartridge when the cartridge is completely installed in the main body of the apparatus; FIG.
FIG. 9 is an enlarged cross-sectional view of a process cartridge according to a second embodiment of the present invention, FIG. 10 is a plan view when the process cartridge starts to be installed, FIG. 11 is the same view during installation, and FIG. FIG. 13 is an enlarged cross-sectional view of the process cartridge during installation, FIG. 14 is an enlarged vertical cross-sectional view of the process cartridge when installation is completed, and FIGS. 15, 16, and 17. The figure is a cross-sectional view showing another example of the structure of the process cartridge. 3 is an image bearing member (photosensitive drum), 4 and 5Φ14 are various constituent units that are image forming means (charger and developer Φ cleaner), 31 and 32 are guide rails, 33 and 34 are ribs, 2
01.202 is Coro. Figure 8 Figure 7 Figure 12 Figure 13 Figure 14 Figure 15

Claims (1)

[Claims] (1) In a process cartridge configured such that an image carrier is attached to the apparatus main body, some of the constituent units used for image formation located near the image carrier are housed in a housing, and the process cartridge is removably attached to the apparatus main body, A process cartridge characterized in that the component unit is provided with an abutting member that moves the component unit housed in the casing away from the image carrier in conjunction with the operation of attaching and detaching the casing to the apparatus main body.