JP2002091267A - Process cartridge and method of disassembling process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the disassembling and recycling of process cartridges of a long-life developing device possible by enhancing the torsional rigidity of the cartridges to improve images and making the coupling form of the process cartridges in such a manner that the disassembly thereof is possible. SOLUTION: Respective frames (cleaning frames 14, toner frames 50 and side covers 37 and 38) are joined. The vicinities of the outer peripheral parts of the joined parts are coupled by hot melt. The hot melt of, for example, an EVA system, which melts at the temperature higher than the temperature in the machine and below the glass transition point of the frame materials, is used for the hot melt. The hot melt is destroyed by heating in disassembly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge used in an electrophotographic image forming apparatus such as a copying machine and a printer, and a method of disassembling a frame of the process cartridge.

Here, an electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming method. And, as an example of the electrophotographic image forming apparatus,
For example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, and the like), a facsimile machine, a word processor, and the like are included.

A process cartridge is a unit in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive drum are integrally formed into a cartridge, and this cartridge is made detachable from an image forming apparatus main body. In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive drum are integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body. Further, at least the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge so as to be detachable from the apparatus main body.

[0004]

2. Description of the Related Art In an image forming apparatus using electrophotography, if the image forming apparatus is used for a long time, the photosensitive drum is replaced, the developer is replenished or replaced, and other (charging device, cleaning container, etc.) adjustment, cleaning, and replacement are performed. However, such maintenance work has been practically difficult except for service personnel having specialized knowledge.

Therefore, in an image forming apparatus using an electrophotographic image forming process, the electrophotographic photosensitive member and the process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is mounted on the main body of the image forming apparatus. A detachable process cartridge system is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a serviceman, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

With the process cartridge having such a configuration, if maintenance is required for the above process equipment, the user can easily perform maintenance and replacement by himself / herself, and high quality image can be obtained at low cost. ,Also,
It has become easier to obtain.

Referring to FIG. 3 of the embodiment of the present invention,
In the electrophotographic image formation including such a process cartridge, the process cartridge includes a cleaning frame 14, which integrally supports a photosensitive drum 15, a charging roller 17, and a cleaning blade 16, a developing roller 20s, and a developing blade. The developing frame 19 that integrally supports, and the developer accommodating frame that accommodates the toner (hereinafter, referred to as a developer accommodating frame).
50 (referred to as a toner frame). Further, in order to integrally support these three frames, the frame is fixed to side covers 37 and 38 with small screws on both side surfaces of the frame, thereby forming a process cartridge.

[0008]

However, the above-mentioned process cartridge has the following problems.

Since the cleaning frame and the toner container are sandwiched between the side covers by the side covers, it is difficult to secure the torsional rigidity of the entire process cartridge. It is essential to increase the overall rigidity due to the influence.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a process cartridge which improves the torsional rigidity of a process cartridge employing a long-life developing device and improves an image. is there.
Further, the present invention provides a process cartridge which can be disassembled in the above manner and a disassembly method thereof.

[0011]

The main aspects of the present invention are as described below with reference to the claims.

According to a first aspect of the present invention, there is provided an electrophotographic photosensitive drum, a first frame supporting the electrophotographic photosensitive drum, and an electrophotographic photosensitive drum. Frame containing a developer for developing the electrostatic latent image formed on the first and second frames using a developer, and third and fourth frames joined respectively over the first frame and the second frame. Wherein the joints are joined by a hot melt that can be broken at a temperature lower than the glass transition temperature of each frame body.

According to a tenth aspect of the present invention, there is provided a method of disassembling a process cartridge detachable from an image forming apparatus main body, comprising: an electrophotographic photosensitive drum; a first frame supporting the electrophotographic photosensitive drum; A second frame containing a developer for developing the electrostatic latent image formed on the photoconductor drum using a developer, and a third frame and a third frame which are respectively joined to the first frame and the second frame. A four-frame body, wherein the bonding portion is bonded with a hot melt that can be broken at a temperature lower than the glass transition temperature of each frame, wherein the bonding portion is a frame material. A process cartridge disassembling method, wherein the process cartridge can be disassembled by applying a temperature equal to or lower than the glass transition point of impact polystyrene.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

In the following description, the longitudinal direction of the process cartridge refers to a direction crossing the transport direction of the recording medium and parallel to the recording medium.

[Description of Process Cartridge and Apparatus Main Body] FIG. 1 is a main cross-sectional view of a process cartridge according to the present invention, and FIG. 2 is a main cross-sectional view of an electrophotographic image forming apparatus (hereinafter, referred to as an image forming apparatus) according to the present invention. Illustrated. This process cartridge is provided with an image carrier and a process means acting on the image carrier. Here, as the process means, there are, for example, a charging means for charging the surface of the image carrier, a developing device for forming a toner image on the image carrier, and a cleaning means for removing toner remaining on the surface of the image carrier.

The process cartridge 13 according to the present embodiment
As shown in FIG. 1, a charging roller 17 serving as charging means is provided around an electrophotographic photosensitive drum 15 serving as an image carrier, a developing roller 20 s and a developing blade 20 b serving as a developing device.
A toner storage frame 50 storing toner and a cleaning blade 16 as cleaning means are arranged, covered with a housing and integrally formed as a process cartridge 13, and configured to be detachable from the image forming apparatus main body C. .

The process cartridge 13 is mounted on an image forming apparatus C as shown in FIG. 2 and used for image formation. In image formation, a sheet 2 is fed out from a sheet cassette 1 mounted at a lower portion of the apparatus by a feed roller 3, and then the sheet 2 is conveyed as a recording medium by a conveying roller 7a.
The sheet 2 is made to stand by by the registration roller 7b, and in synchronization with the sheet conveyance, the photosensitive drum 15 is selectively exposed from the exposure device 30 to form a latent image. Thereafter, a thin layer of the toner stored in a developer storage container (hereinafter referred to as a toner container) 50 is carried on the surface of the developing roller 20s by the developing blade 20b, and a developing bias is applied to the developing roller 20s, so that the photosensitive roller is exposed in accordance with the latent image. The toner is supplied to the body drum 15 to form a toner image. The registration roller 7b is synchronized with the formation of the toner image on the photosensitive drum 15 and the timing.
To feed the sheet 2 to the opposing portion between the transfer roller 10 and the photosensitive drum 15. This toner image is transferred to the sheet 2 conveyed by applying a bias voltage to the transfer roller 10, and
The sheet 2 is conveyed to the fixing device 25 to fix the image, and is discharged by the discharge rollers 34 and 35 to the discharge portion 24 in the upper portion of the device.

The process cartridge 13 is attached to and detached from the apparatus main body 18 through an opening (not shown) of the apparatus main body 18 on the near side parallel to the plane of FIG.

[Frame Structure of Process Cartridge] FIGS. 3 and 4 are perspective views showing the frame structure. FIG. 3 is a diagram before the frame is assembled, and FIG. 4 is a diagram after the frame is assembled. The process cartridge 13 includes the photosensitive drum 1
5, a cleaning frame 14 integrally supporting a charging roller 17, a cleaning blade 16, and a developing roller 2.
0s, a developing frame 19 that integrally supports the developing blade 20b (not shown in FIG. 3), and a toner frame 50 that stores toner. Further, in order to integrally support the three frames, the three frames are fixed by side covers 37 and 38, which are other frames, on both side surfaces of the frame, thereby forming a process cartridge. The developing roller 20 s is rotatably supported by the developing frame 19. The cleaning frame 14 fixes the cleaning blade 16 with small screws or the like, and the charging roller 17 rotatably supports the end of the cored bar 17a via a bearing member (not shown). Also, the photosensitive drum 15 has flange portions 15a, 15b at both ends thereof, respectively, bearing members 39a, 39b.
It is rotatably supported via. The toner frame 50 contains a toner as a developer together with a toner conveying member (not shown). Details of the developing frame 19 will be described later. One side cover 37 is large enough to cover the main cross section of the process cartridge 13, and is disposed at one end of the process cartridge in the longitudinal direction.
The cleaning frame 14 and the toner frame 50 are integrally supported from both sides. The hole 37a of this side cover 37
Are positioned coaxially with the center of the photosensitive drum 15 of the cleaning frame 14. At this time, the positioning of the side cover 37 via the bearing member 39a is determined with high accuracy. Further, a positioning portion 37b, which is a dowel provided as far away from the photosensitive drum 15 as possible, is fitted to a positioning portion 14b, which is a hole provided on a side surface of the cleaning frame 14, to determine a position in the rotation direction. After the positioning, it is fixed with a hot melt described later. Further, the toner frame 50 is provided with dowel-shaped positioning portions 50a and 50b protruding in the longitudinal direction (axial direction of the photosensitive drum 15) on one end surface thereof. After the position is determined by certain positioning portions 37c and 37d, it is fixed by hot melt described later. The other side cover 38 is similarly positioned on the developing frame 19. Further, the bearing members 39a and 39b also serve for positioning with respect to the image forming apparatus main body. The bearing members 39a and 39b are press-fitted into the holes 14a at the ends in the longitudinal direction of the cleaning frame 14, and in the assembled state, as shown in FIG. And project outward. The projecting bearing members 39a,
39b fits into a positioning portion provided in the apparatus main body 18. From the toner frame 50 to the developing roller 20s
Frame 50, developing frame 1
9, a toner receiving opening 19a and a toner supply opening 50
c is provided. As shown in FIG. 1, the developing frame 19 and the toner frame 50 are connected by a seal member 44 connecting the openings. Both ends of the seal member 44 are fixed to the toner receiving opening 19a and the toner supply opening 50c, respectively, and the fixed portions are hermetically sealed.
The toner moving toward 9a is prevented from leaking outside. The toner frame 50 is provided with side covers 37 and 3.
8 and the developing frame 19 is positioned by the cleaning frame 14, so that there is a possibility that the developing frame 19 and the toner frame 50 may be distorted due to a dimensional error. Therefore, the seal member 44 uses a flexible material (flexible member).

The configuration described above, namely, 1. By connecting the side surfaces of the frames 14, 50, the cleaning frame 14 and the toner frame 50 can be positioned by the side covers 37, 38, and can be connected with high accuracy.

2. A hot melt (described in detail later) 154a in the sectional view of the joint (FIG. 5) and 200 in the schematic view (FIG. 6) is injected into the side surface of each of the frames 14, 50 and the vicinity of the outer periphery. By coupling, the torsional rigidity of the entire process cartridge can be ensured, and the overall rigidity can be increased due to the effect of the weight of the developer due to the large capacity.

3. In addition, as described later, when disassembling / recycling is performed, the heating means 201 (heating wire 201a
And the like are brought to the site bonded by hot melt, and the hot melt is softened and decomposed at a temperature equal to or higher than the in-machine temperature shown in Table 1 and equal to or lower than the glass transition point of the material of the frame.

[Structure of Developing Frame] The developing frame 19 has developing means 20. As the developing means 20, a magnet roller (not shown) is included in the developing roller 20s. A developing blade 20b and a magnetic seal (not shown) are provided. The magnet roller is supported by the developing frame 19 and maintains a gap with the developing roller 20s. Further, power is supplied to the developing roller 20s by providing an electric contact inside the developing roller 20s. Further, on the developing roller 20s, there is provided a contact roller (not shown) for keeping a constant distance from the photosensitive drum 15.

The developing frame 19 is swingably supported by a suspension hole 19d provided on the driving side of the developing roller 20s as a center of swinging rotation, with the center of the developing roller 20s facing the center of the photosensitive drum 15. I have. That is, the developing frame 19 including the developing roller 20s is provided with the arm 19c on the driving side on the cleaning frame 14, and the hanging hole 19d is provided in the arm 19c.
And the toner frame 50 and the cleaning frame 14 are fixed without moving relatively as described above, so that the developing frame 19 is Are relatively movable.

Further, the non-driving side of the developing frame 19 (the arm 19)
On the opposite side of the developing roller 20s in the longitudinal direction, a projection (not shown) is provided on the longitudinal central axis of the developing roller 20s, and the projection is pressed toward the center of the photosensitive drum 15 by a spring (not shown). It is configured as follows.

The protrusion is inserted into a groove (in this embodiment, a linear elongated hole substantially parallel to the center direction of the photosensitive drum 15) provided in the side cover 37, and is inserted in the center direction of the photosensitive drum 15. It is configured to be movable. An elastic member is provided inside the groove so as to press the projection.

The groove also plays a role of positioning for regulating the moving direction of the developing roller 20s. When the driving force is applied here, the photosensitive drum 15 and the developing roller 20s
Are designed so that a force acts in the direction of biting each other around the suspension hole 19d, and no force acts in a direction in which the photosensitive drum 15 and the developing roller 20s are separated from each other. Also, the developing roller 20s is always pressed toward the photosensitive drum 15 by the elastic member described above.

Since the developing frame 19 and the developer accommodating container 50 are relatively movable, they are connected by a flexible seal member 44 that absorbs the moving range of both, so that toner leakage is prevented.

[Toner Frame] The toner frame 50 is provided with toner conveying members 50e and 50f. The toner supply opening 50c is sealed with a toner seal (not shown), and the toner is filled in the toner frame 50.

The toner seal is passed through the seal member 44 in a sealed state and is discharged outside. When the process cartridge 13 is started to be used, the toner seal is pulled out, and the toner supply opening 50c is opened.

[Cleaning Frame] Cleaning Frame 1
A cleaning blade 16 is attached to 4. Therefore, the cleaning blade 16 is
The transfer residual toner wound up from No. 5 is sent to the removed toner reservoir 14d by the feeding member 14e.

[Combined Structure of Cleaning Frame and Toner Frame] As described above, the process cartridge 13 is arranged in the longitudinal direction of the cleaning frame 14 (as described above, the longitudinal direction is parallel to the axial direction of the photosensitive drum 15). The edges 40 of the side covers 37, 38 are joined to the peripheral edges of both end faces 14c, 14c. Further, the toner frame 5
The edges 40 of the side covers 37, 38 are joined to the peripheral edges of both end surfaces 50d, 50d in the longitudinal direction of the zero.

FIG. 5 shows both end surfaces 14 of the cleaning frame 14.
c, the peripheral edges of 14c or both end faces 50d of the toner frame 14;
The cross section of the peripheral edge of 50d and the edges of the side covers 37 and 38 at right angles to the inner edge and the outer edge of the edge is shown. As shown in FIG. 5, abutment portions 154 of the grooves are provided on the peripheral edges of both end surfaces in the longitudinal direction of the cleaning frame 14 and the toner frame 50, and the abutment portions 154 have ethylene vinyl acetate ( EVA) The copolymer resin is injected and solidified.

FIG. 6 schematically shows a frame body to be joined. At the joint of the frames A and B, the two frames A and B
Thus, the groove 200c that is opened outward is formed. Ethylene vinyl acetate (EV
A) The copolymer resin is injected and solidified. Here, the hot melt is an EVA type represented by an ethylene acetic acid copolymer resin.

5 and 6, the resin frame to be joined is accommodated in the mold in a temporarily joined form, and in FIG. 5, the runner way and the gate in the mold are passed through.
The resin can be injected into the abutting portion 154 through which the resin injection flow path is opened through the resin injection flow path directly connected to the gate in the side covers 37 and 38 (not shown). In FIG. 6, the abutting portion 200 is formed as a resin injecting space together with a mold, and a hot melt 200 a as a molten resin is injected into the abutting portion 200 through a runway and a gate in the mold and solidified. Is done.

The above-described cleaning frame 14, toner frame 50, and side covers 37 and 38 are each formed of high impact polystyrene HI-PS. Cleaning frame 14, toner frame 50, side covers 37, 3
In addition to the above, acrylonitrile-butadiene-styrene copolymer ABS resin, modified poly-phenylene-ether resin mPPE, modified poly-phenylene-oxide PPO, etc. may be used.

Here, as the hot melt material injected into the abutting portions 154 and 200, the cleaning frame 14, which is the first frame, the toner frame 50, which is the second frame, and the third and fourth heat-resistant materials are provided. Those having a lower temperature than the glass transition point of the side covers 37 and 38 as the frames are selected.

Table 1 shows the hot melt properties.

Here, the load heat resistance is 5 mm × 25 mm ×
100 mm birch test pieces are bonded together to form a 25 mm lap shear test piece, which is cured at 23 ° C. and 50% RH for 24 hours. A 200 g weight was lowered on the test piece and kept at 38 ° C. for 15 minutes. Thereafter, the temperature of the test piece was raised at a rate of 2 ° C. in 5 minutes until the bonded portion was peeled off, and the temperature of the test piece at the time of bond failure was recorded. Things.

Table 2 shows the glass transition points of the materials that can be used as the frame material.

As shown in FIG. 6 (a), a heating wire 201a is arranged along the hot melt 200a filled in the abutting portion 200, and an alternating current and a direct current are applied to the heating wire 201a together. The temperature gradually rises until the surface temperature does not exceed the glass transition point of the frames A and B and the hot melt 200a is broken.

During heating by the heating wire 201a, both frames A,
A load is always applied to both frames A and B as indicated by arrow P in the direction in which B moves away. Hot melt 2 made of ethylene vinyl acetate (EVA) copolymer resin adopted by this
00a was destroyed at a temperature of 70 ° C., and both frames A and B were separated. During this operation, the external surface temperature of the process cartridge 13 was about 30 to 50 ° C. at a room temperature of 23 ° C. Due to such separation, the joint portions including the fitting portions Aa, Ba of the frame bodies A, B are not damaged at all, and the process cartridge 13 can be disassembled, regenerated, and reassembled.

In the case of FIG. 5, similarly to FIG. 6, a heating wire is provided along the abutting portion 154 apart from the abutting portion 154 and heated. In this case, since there is an outer peripheral member 154b that constitutes the outer peripheral portion of the abutment portion 154, the operation is the same except that it takes more time to raise the temperature of the hot melt than in the case of FIG. .

[0045]

As described above, according to the invention of the present application, the torsional rigidity of the process cartridge having the long life developing device can be increased, and the image can be improved. Further, the connection form of the process cartridge can be disassembled, and disassembly and recycling are possible.

[Brief description of the drawings]

FIG. 1 is a schematic main cross-sectional view of a process cartridge according to an embodiment of the present invention.

FIG. 2 is a schematic main cross-sectional view of an apparatus main body according to the embodiment of the present invention.

FIG. 3 is an exploded perspective view schematically showing a frame structure of a process cartridge according to the embodiment of the present invention.

FIG. 4 is a perspective view schematically showing a frame structure of a process cartridge according to the embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of the joining portion of the process cartridge according to the embodiment of the present invention, which is cut in the inner and outer directions.

FIGS. 6A and 6B are longitudinal sectional views for explaining separation of a joint portion of a frame body according to the embodiment of the present invention, wherein FIG. 6A is a view before separation and FIG. 6B is a view after separation.

[Explanation of symbols]

A: Frame B: Frame C: Image forming apparatus 1: Sheet cassette 2: Sheet 3: Feeding roller 7: Conveying roller 10: Transfer roller 13: Process cartridge 14: Cleaning frame 14a: Hole 14b: Positioning section 14c ... End face 14d ... Removed toner reservoir 14e ... Feeding member 15 ... Photoreceptor drum 15a, 15b ... Flange part 16 ... Cleaning blade 17 ... Charging roller 17a ... Core metal part 18 ... Device main body 19 ... Development frame 19a ... Reception opening 19c ... Arm 19d ... Hanging hole 20 ... Developing means 20s ... Developing roller 20b ... Developing blade 24 ... Discharge unit 25 ... Fixing device 30 ... Exposure device 34 ... Discharge roller 35 ... Discharge roller 37 ... Side cover 37a ... Hole 37b, 37c,
37d ... Positioning part 38 ... Side cover 39, 39a, 39b ... Bearing member 40 ... Edge 44 ... Seal member 50 ... Toner frame body 50a, 50b ... Positioning part 50
c: toner supply opening 50d: end surface 50e, 50f: toner conveying member 154: abutting portion 154a: hot melt 154b
Outer peripheral member 200: abutting part 200a: hot melt 200c ...
Groove 201: Heating means 201a: Heating wire.

Claims (10)

[Claims] An electrophotographic photosensitive drum; a first frame supporting the electrophotographic photosensitive drum; and an electrostatic latent formed on the electrophotographic photosensitive drum. A second frame housing a developer for developing an image using a developer, a third frame joined to the first frame and the second frame, respectively,
And a fourth frame, wherein the joints are joined by a hot melt that can be broken at a temperature lower than the glass transition temperature of each frame. 2. The process cartridge according to claim 1, wherein the hot melt is an EVA resin represented by an ethylene vinyl acetate (EVA) copolymer resin. 3. The process according to claim 1, wherein the frame material is an acrylonitrile-butadiene-styrene copolymer ABS, a polyphenylene ether-modified PPE, or a polyphenylene oxide-modified PPO. cartridge. 4. The process cartridge according to claim 1, wherein the first frame and the second frame are respectively positioned on the third frame and the fourth frame. . 5. A developing frame for developing an electrostatic latent image formed on an electrophotographic photosensitive drum using a developer, wherein the developing member is movably attached to the first frame. The process cartridge according to any one of claims 1 to 4, wherein the process cartridge is attached. 6. A developer supply opening provided in the second frame for sending out the developer opened toward the developing frame, a developer receiving opening provided in the developing frame and opposed to the developer supply opening. A flexible cylindrical seal member in which the developer moves inside between the developer supply opening and the developer receiving opening, one end of which is hermetically fixed to the peripheral edge of the developer supply opening, and the other end thereof. The process cartridge according to any one of claims 1 to 5, further comprising a seal member hermetically sealed to a peripheral edge of the developer receiving opening. 7. The process cartridge, wherein a charging unit, a cleaning unit, a developing unit, and an electrophotographic photosensitive drum are integrally formed into a cartridge, and the cartridge is detachably mountable to an image forming apparatus main body. 7. The process cartridge according to any one of 1 to 6. 8. The process cartridge according to claim 1, wherein at least one of a charging unit, a cleaning unit, a developing unit, and an electrophotographic photosensitive drum are integrated into a cartridge to be detachable from an image forming apparatus main body. 7. The process cartridge according to any one of 6. 9. The process cartridge according to claim 1, wherein the developing unit and the electrophotographic photosensitive drum are integrally formed into a cartridge, and the process cartridge is detachably mountable to an image forming apparatus main body. . 10. A method for disassembling a process cartridge detachable from a main body of an image forming apparatus, comprising: an electrophotographic photosensitive drum; a first frame supporting the electrophotographic photosensitive drum; A second frame housing a developer for developing the electrostatic latent image using a developer, a third frame joined to the first frame and the second frame, respectively,
And a fourth frame, wherein the bonding portion is bonded with a hot melt that can be broken at a temperature lower than the glass transition temperature of each frame, wherein the bonding portion is a frame material, By applying a temperature below the glass transition point of high impact polystyrene,
A method for disassembling a process cartridge, wherein the process cartridge can be disassembled.