JPH0334071B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process cartridge that includes an image carrier and at least a developing unit as a process unit that acts on the image carrier, and is detachable from an image forming apparatus. Conventionally, an image carrier such as a photoreceptor, which deteriorates depending on the amount of use and has a limited durability, and a process means that acts on this image carrier are integrated into a cartridge that can be attached and detached from the image forming apparatus. Consideration has been given to configuring and facilitating the replacement of consumables. To replace these consumables, use a developing device that reaches its usage limit due to toner consumption, a cleaning device that accumulates used toner, a corona discharge device that tends to cause discharge failure due to toner adhesion, etc., in combination with the photoreceptor as appropriate. It may also be effective to replace the photoconductor at the same time. A structure in which consumables that need to be replaced as they are used can be attached to and detached from the image forming apparatus is herein referred to as a process cartridge. By the way, if an image carrier such as a photoconductor is considered as a standard consumable item, the amount of developer in a developing device for developing the latent image on the photoconductor will be consumed at the same time as the photoconductor reaches its usage limit. can be said to be the most economical.
Therefore, in a process cartridge in which the photoreceptor is considered a standard consumable item, it is preferable to provide a developing device together with the photoreceptor in the process cartridge. On the other hand, when installing a photoreceptor and a developing device into a process cartridge, if the developing device is not positioned reliably with respect to the photoreceptor, image defects may occur. Furthermore, when mass production of process cartridges is considered, it is desired that process cartridges incorporating a photoreceptor and a developing device be easy to assemble. SUMMARY OF THE INVENTION An object of the present invention is to provide a process cartridge that allows easy positioning of an image bearing member and a developing device and is excellent in assembling the process cartridge. To achieve the above object, the present invention provides a process cartridge which includes an image bearing member and at least a developing means as a process means acting on the image bearing member, and which is removably attached to an image forming apparatus. An integrally molded process cartridge housing is provided with an opening so that the image bearing member and the developing means can be assembled therein, and has respective positioning standards for the image bearing member and the developing means, and a container for the developing means is attached to the housing. In order to position the container of the developing means, a plurality of positioning members are inserted into reference holes of the housing from both outsides of the housing in the longitudinal direction of the container of the developing means to support the container of the developing means; A biasing member for biasing the container of the developing means toward the image carrier. Embodiments of the present invention will be described below using an electrophotographic copying machine as an example. The present invention is applicable not only to image forming apparatuses using electrophotography but also to electrostatic recording apparatuses that record on an insulator as an image carrier using electrodes or the like. FIGS. 1 and 2 are diagrams illustrating the configuration of an embodiment of an electrophotographic copying machine. Note that FIG. 2 is a diagram showing the copying machine shown in FIG. 1 in an open state. In FIG. 1, reference numeral 1 denotes a document mounting table made of a transparent member, which reciprocates in the direction of the arrow. 2 is an imaging element array that converts the optical image of the original on the original platen 1 into an image carrier.
Slit exposure is performed on the OPC photosensitive drum 3. In addition,
The photosensitive drum 3 rotates in the direction of the arrow. 4 is a corona charger that uniformly charges the photosensitive drum. Further, 5 is a developing device which develops an electrostatic latent image formed by exposing a uniformly charged photosensitive drum to light using the array 2 with toner. On the other hand, the transfer sheet P is fed onto the surface of the drum 3 by a feeding roller 6 and a register roller 7, and the toner image on the 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 is sent to the fixing device 10 by the roller 9a located at the end of the conveyance path. The toner image on the sheet is fixed by a fixing device 10, and the sheet is transferred to a tray 12 by a discharge roller 11.
is discharged to the top. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14. Furthermore, 15 is an illumination system for exposing the original, and 16 is a filter such as a heat ray absorption filter. Now, as shown in FIG. 2, this copying machine is divided into an upper housing 17 and a lower housing 18, which are connected by a support shaft 19 so as to be separable, and the upper housing 17 rotates upward around this support shaft 19. It is configured to move. This upper housing 17 includes illumination optical systems 2, 15, photosensitive drum 3,
Image forming means such as a developing means 5 and a cleaning device 14 are arranged. In addition, the lower housing 18 includes
A feeding roller 6, a transfer charger 8, a separation means 13, a guide 9, a fixing device 10, and the like are arranged on the sheet conveyance path. Furthermore, in this embodiment, the process cartridge 30 is constructed by integrating process means such as the developing device 5, the cleaning means 14, and the charging device 4, which are arranged around the photosensitive drum 3, and surrounding the photosensitive drum 3 with a light-shielding wall. At the time of replacement, each unit in the cartridge 30 is replaced at the same time, thereby reducing maintenance work. The process cartridge is attached to and detached from the main unit by moving the cartridge 30 along the rails 31 and 32 on the copying machine main body side in the direction of the rotation axis of the drum 3. Note that the case where this cartridge 30 is taken out from the main body will be described below. Reference numeral 20 located at the bottom of the cartridge is a cover that blocks light and protects the exposed surface of the drum 3, which is made of an opaque black ABS resin of the same quality as the wall portion 30a of the process cartridge, and an example of its configuration is shown in FIG. As shown, there are swing arms 21 on both ends of the drum in the longitudinal direction on the same axis 3a as the photosensitive drum 3.
a and 21b, the ends of which are rotatably fitted to both ends of the drum cover 20 in the longitudinal direction via a shaft 33. Furthermore, both longitudinal ends of the other end of the drum cover 20 are rotatably engaged with the swing arms 22a, 22b around a shaft 34. Also,
The swing arms 22a, 22b are fixed to a shaft 23, and an actuation lever 25 is further provided at the end of the shaft 23.
is fixed. As shown in the figure, the swinging arms 21a and 21b are given the habit of rotating counterclockwise by a spring 24. Note that 30d in the figure shows a part of the inner cover of the cartridge 30. In the above configuration, when the operating lever 25 is moved clockwise by a mechanism described later, the shaft 23 rotates clockwise, and the cover 20 is moved clockwise by the swinging arms 22a and 22b, one end of which is fixed to this shaft. The photosensitive drum 3 can be rotated and retracted from the circumferential surface of the photosensitive drum 3. That is, in this embodiment, as shown in FIG. 4, a protrusion 26 is integrally fixed to the lower housing 18, and when the cartridge 30 is loaded in a predetermined position, the protrusion 26 is attached to the upper housing 17. When the spring 24 is closed, the spring 24 connects the protrusion 24a on the inner cover 30d and the arm 2.
Both ends of the cover 20 are locked by the protrusions 24b on the photosensitive drum 1a, so when the operating lever 25 is rotated clockwise, the cover 20 is automatically retracted from the drum circumferential surface to expose the photosensitive drum and image formation can be performed. become. Conversely, when the upper housing 17 is opened upward, as shown in FIG. , 21b rotates counterclockwise, and in conjunction with this, the drum cover 20
rotates counterclockwise to reach the vicinity of the circumferential surface of the drum 3, and covers the exposed portion of the photosensitive drum 3 from the wall portion 30a. That is, when the upper housing 17 is opened, the cover 2
0 automatically covers the exposed portion of the circumferential surface of the drum 3 and blocks light, thereby preventing the influence of light on the circumferential surface of the drum 3 and at the same time preventing scratches. Incidentally, in the above description, the case where the photoreceptor surface exposed from the process cartridge is shielded from light by opening and closing a part of the main body device was exemplified. The opening and closing of the main body is performed for maintenance and inspection of the apparatus and for handling defective conveyance of the transfer sheet, and even in such cases, it is possible to protect the photoreceptor surface from being exposed to light. In the configuration of the above embodiment, when a process cartridge is to be attached to or removed from the main unit, the main body housing is divided into upper and lower parts as shown in FIG. Move in the axial direction of the drum. At this time, due to the configuration of the drum cover, the exposed portion of the transfer portion of the drum 3 is shielded from light. However, the wall portion 30a of the process cartridge facing the imaging element array 2 is provided with an opening 27 for guiding the original image to the photosensitive drum. Since this opening 27 is located close to the circumferential surface of the photosensitive drum, if this process cartridge is taken out from the main body and left on a desk, etc., the surrounding natural light or illumination light will cause optical memory to occur on the photosensitive drum. Sometimes I let it happen. In order to solve this problem, the upper opening 27 of the process cartridge of the embodiment has this opening 2.
A light shielding plate is provided to block the 6th
This will be explained according to the diagram. FIG. 6 shows a perspective view of the process cartridge of the present invention taken out from the main unit, and shows the front side when being loaded. On the other hand, FIG. 7 shows a perspective view of the rear side of the cartridge having a connecting portion with the main body. In the figure, 30b indicates that the cartridge body is connected to the rail 31,
Grip part for pulling out along 32, 30c
indicates the handle part for lifting the removed cartridge. There is an opening 27 at the top of the cartridge 30 for exposure, and in this embodiment, a rotatable light shielding plate 28 is disposed along this opening. This light shielding plate 28 is made of ABS resin that has the same light shielding function as the wall, and this light shielding plate 28 is
By tilting the photosensitive drum 3 in the direction to close the opening 27, the photosensitive drum 3 can be completely shielded from surrounding light, and a memory phenomenon caused by light irradiation on the photosensitive drum will not occur. At the back end of this light shielding plate, there is a convex portion 28a bent at a right angle. The state of the light shielding plate in FIG. 7 shows when the process cartridge 30 is usable. When taking out this cartridge from the main body, rotate the light shielding plate in the direction of arrow a (FIG. 7) to bring it into the state shown in the figure. As a result, the convex portion 28a stands up on the back side of the cartridge as shown in the figure. When attempting to load the cartridge 30 into the main unit in the state shown in FIG. 6, the imaging element array 2 comes into contact with this convex portion 28a, making it impossible to load the cartridge, and as a result, the light shielding plate closes the opening 27. I can recognize that there is. The process cartridge 30 has an opening 35 for guiding pre-exposure light between the corona discharger 4 and the cleaning device 14 of the photosensitive drum. Although this opening 35 has a smaller opening area than the opening 27,
The light from this opening 35 also has an adverse effect on the photoreceptor. For such an aperture that has a small opening area and does not allow image light to pass through, a milky white fixed plate may be fixed to the aperture 35 instead of using a light shielding plate such as the light shielding plate 28 described above. Instead of this milky-white plate, the photosensitive drum may use a transparent plate with a color such as yellow or red that transmits wavelengths that do not react. By the way, as materials that can be used for the walls of the process cartridge and the covers and plate members for light shielding, opaque materials such as noryl resin, polycarbonate resin, ABS resin, metal, and rubber that block light can be used. It is. Alternatively, if the photosensitive layer of the photoreceptor is made of a material that absorbs or reflects the wavelength at which it reacts, it is also possible to use a transparent resin. Furthermore, the portion of the member that moves or rotates relative to the opening in the wall and comes into contact with the wall of the member that closes the opening includes:
By attaching an opaque elastic material such as maltplane or felt, the light-shielding function can be further enhanced. Furthermore, since this light-shielding cover covers the circumferential surface of the photoreceptor, it also serves as a protective cover against external forces. As shown in FIG. 7, on the back side of the process cartridge 30, there are positioning pins 36 for correcting the position of the cartridge loaded in the main unit, and a connector 37 for supplying high voltage to the charger 4. and a drive transmission gear 3 that drives the photosensitive drum 3.
8, and a connector 39 for applying a bias voltage to the developing device 5. The gear 38 transmits the driving force of the main body to the drum 3 by fitting its concavo-convex portion with the concave-convex portion of the drive gear on the main body side. The final positioning of the process cartridge 30 with respect to the main body is achieved by fitting a positioning hole 40 provided on the side opposite to the back wall with a pin (not shown) on the main body side. By the way, in order to increase the compatibility of the cartridge itself and to always form a stable image, the process cartridge 30 adjusts the light intensity of the original image on the main body copying device side according to the characteristics of the photosensitive drum loaded in each cartridge. change automatically. Specifically, as shown in FIGS. 6 and 7, a recess setting part 41 is provided in a part of the outer wall of the cartridge, and a detection means such as a micro switch is provided on the main body side corresponding to the setting part. By selectively filling this recess according to the characteristics of the photosensitive drum, a micro switch provided on the main body side can detect the presence or absence of this recess and issue a signal. In this embodiment, since there are two recessed portions, four modes are possible depending on the combination of "filling" and "not filling". Furthermore, since the grip portion 30b used to take out the process cartridge has a convex portion upward, it is difficult to continue holding the cartridge by gripping the grip portion 30b after pulling the cartridge out. Therefore, since the cartridge is carried by the handle portion 30c after being pulled out, the cartridge is not carried with the loading direction vertical, and as a result, the toner, which is the developer in the developing device 5 and the cleaning device 14, is This prevents toner from shifting in the developing device or cleaning device, effectively preventing toner scattering and development troubles. A counting means for measuring the amount of used process cartridges is included inside the grip portion 30b, and therefore, the grip portion also serves as a cover for this counting means. This counting means uses a plurality of gears to further reduce the amount of rotation of the gear driven by the rotation of the photosensitive drum, and finally drives the display gear. This display gear is blue, yellow,
It has a three-color band of red, and a part of this color band of the display gear can be seen through the observation aperture 42. That is, while this opening 42 is displaying blue, it can be used.
If the color becomes red, replace the process cartridge with a new one. Of course, this opening 42 corresponds to the opening of the front door of the main body, and the display by the display gear will actually be observed from this front door. Although the above description has focused on the outside of the process cartridge 30, each means provided inside the process cartridge will now be described. First, Fig. 8 is a front view of the photosensitive drum section. The photosensitive drum 3, which is rotatably attached to the center of the cartridge, is made of aluminum and is molded using impact molding. The boss portion 3a is integrally molded. On the other hand, a flange 43 is fixed to the opening side 42 of the drum, and this flange 43 is rotatably supported by a shaft 44 fixed to the cartridge housing. On the rear side, a drive transmission gear 38 fixed to the boss portion 3a of the drum 3 is rotatably supported by the cartridge housing. This transmission gear 38 has a radial rib as shown in FIG. 7, and when the pin 46 of the gear 45 on the main body side engages with this rib and rotates, the gear 38 is driven, and as a result, the drum 3
rotates. The boss portion 3a at the end of the drum 3 has a
A bearing 47 is press-fitted, and this bearing 47 fits into a recess 48 on the main body side to position the center of the drum on the back side of the cartridge. Note that the tooth portion provided on the transmission gear 38 on the cartridge side meshes with the gear on the end of the developing sleeve, which will be described later, to drive the developing sleeve and further drive the scraping member 69 (FIG. 13) of the cleaning device. It is in. Around the photosensitive drum in the process cartridge, a corona charger, a developer,
Each means of the cleaning device is further arranged as a process means. FIG. 9 shows a front sectional view of the charger 4, and the height accuracy of the discharge wire 49 of this corona charger with respect to the surface of the photosensitive drum 3 is achieved by using rollers 50 that come into contact with the drum surface. Specifically, the discharge wire 49
Both ends are fixed with rivets 51, and rollers 5
A top 52 that is driven vertically in a direction perpendicular to the surface of the photosensitive drum 3 having a surface of 0 is biased toward the drum by a wire 49. A V-shaped groove is cut on the opposite side of the top 52 from the rollers, and a wire 49 is guided into this groove. FIG. 10 shows a partially enlarged cross-sectional view of the end portion, and 53 in the figure shows the rotation axis of the roller, which is provided integrally with the top 52. The above configuration enables more accurate positioning of the discharge wire with respect to the photoreceptor surface. FIG. 11 shows a cross-sectional view of the developing device, and a one-component magnetic toner is used as the developer. Reference numeral 54 in the figure represents a cylindrical developing sleeve made of a non-magnetic material such as aluminum or stainless steel, which is driven to rotate in the clockwise direction of the arrow. A magnet roller 55 is inserted into the sleeve to attract magnetic toner onto the sleeve. The toner on the sleeve is adjusted to an appropriate thickness by cooperation of the magnetic force of the magnet 55 and the magnetic blade 56, which is a toner thickness regulating member provided close to the sleeve surface. The toner coated on the surface of the sleeve 54 in this manner is moved onto the photosensitive drum at a position facing the photosensitive drum 3 by electrostatic force due to the latent image on the drum surface and AC bias led from the connector 39 (FIG. 7). It adheres to the electrostatic latent image and develops it. The amount of toner 57 in the developing device is
It is set in consideration of the durability of the photosensitive drum, and is set so that when a normal original is used within the range where the photosensitive drum can be used, a small amount of toner remains. Also, before purchasing a cartridge and loading it into the main unit,
It is divided by a partition plate 58 into a toner storage chamber 59 which also serves as a hopper, and a toner application chamber 60 which applies toner to the drum surface. Toner is applied to the drum surface by the sleeve 54 and magnet 55 of this application chamber 60. The partition plate 58 can be removed from the cartridge by pulling out the end 58a protruding from the side of the developing device 5 in the direction of the arrow. When the partition plate 58 is removed, the toner in the storage chamber falls to completely fill the space in the application chamber, completing preparations for image formation. Next, the filling of toner into the developing device will be described. In this process cartridge manufacturing process, the lower casing 61 of the developing device and the upper casing 62 constituting the storage chamber are connected by ultrasonic welding at the joint of both casings with a partition plate installed between them. Welded or adhered using a welding means such as a container or a strong adhesive.
As a result, the storage chamber 59 and the application chamber 60 are separated by the partition plate 5
8. Therefore, a predetermined amount of toner is sealed with the opening 63 provided on the side of the upper casing 62 of the cartridge facing upward. After the sealing is completed, the opening 63 is covered, and a surface casing 64 that covers the entire upper and side portions is non-removably fixed with screws or adhesive. As a result, it is impossible to improve or adjust the interior of the process cartridge once it has been assembled. Of course, in the above embodiment, the hole 6
The lid attached to No. 3 cannot be seen or touched from the outside of the cartridge. Therefore, it is virtually impossible to replenish the developing device with another toner, and even if you ignore the display of the photoreceptor's durability limit or use it without realizing it, the cartridge may become depleted due to the toner being used up. An exchange will inevitably take place. That is, the configuration of the developing device allows the quality of images formed by the main unit to be maintained at a high level at all times. By the way, heat seals, resin sheets, plates, etc. can be used as the partition plate, and a packing member 65 (the first
2), the scattering of toner can be effectively prevented. FIG. 13 shows a sectional view of the cleaning device. The toner remaining and adhering to the surface of the photosensitive drum 3 after the transfer process is scraped off by a rubber plate 66, and a scooping sheet 6 made of, for example, a polyester film with a thickness of about 75 μm is located below the rubber plate 66.
7, it is stored in the container. This scooping sheet 6
The sheet 7 is in light contact with the surface of the drum 3, and the degree of contact is such that residual toner can pass through this sheet. The contact of the sheet 67 against the drum prevents the toner scraped off by the blade 66 from leaking from inside the container to the outside. Reference numeral 68 at the bottom of the cleaning device is a magnet for collecting toner that has fallen to the outside. A portion of the interior of this cleaning device is partitioned by a fixed partition plate 70, and the toner dropped by the blade 66 as described above is pushed into a space 71 at the back of the container by a rotating scraping member 69. By doing so, the apparent density of the toner increases and the container can be made smaller. The scraping member 70 is made of an elastic material such as a polyester sheet or cloth impregnated with rubber, and is driven by a transmission gear 38 through a gear connection. Next, the main steps for assembling the process cartridge will be explained. The process cartridge includes a drum that forms the photoconductor, a developing section with a developing device, a cleaning device that cleans the remaining toner on the drum, a charging section that applies corona charging to the photoconductor drum, and a device that protects the photoconductor from external light. It mainly consists of a protection means, a lifespan display means when a process cartridge is used, and a means having a sensitivity correction function in accordance with the sensitivity characteristics of the photosensitive drum when a process cartridge is loaded into the main body. This is as stated above. Therefore, the assembly procedure of these main parts is explained in the 14th section.
Referring to the figure, first, the process cartridge consists of a housing 100, to which various components are attached to complete the cartridge. The shape of the casing 100 is 100a, 10
It is made up of molded parts that integrally form both sides of 0b, and each component is assembled at the casing position as shown in FIG. Next, the assembly of each component will be explained in detail. First, the charging section will be explained. Although the general structure is described in FIG. 10, the charging section consists of a shield plate 101 made of a conductive material and blocks 102 and 103 heat-welded to it, and each block is made of insulating plastic material or equivalent material. used. The charging wire 49 is an ultra-fine tungsten wire or stainless steel wire to generate corona discharge, and this charging wire 49 is connected to the blocks 102, 1.
03 with a rivet 51, and at the same time conducts the charged wire 49 to the main body side.
A conductive plate 107 is heat welded to the block 103 so as to be in contact with the head of the rivet 51. Next, a height adjustment piece 52 for ensuring the height of the charged wire with respect to the drum surface, a roller 50 rotatably in contact with the drum surface, and a rotating shaft so that the roller 50 is rotatably supported by the height adjustment piece 52. 53 is integrally attached to the height extension piece 52. A pair of the height adjustment pieces 52 are slidably fitted into each of the blocks 103 and 104, and one end of each height adjustment piece is formed with a V-groove into which a charging wire is fitted (see FIGS. 9 and 10). By ensuring the distance between the V-groove and the tip of the roller, the charged wire 49
and the drum surface to ensure uniform charging of the drum. These pieces etc. are block 1
03, 104, the lid 111,
112 is snapped onto blocks 103 and 104. Here 52, 53, 50, 111, 11
2 is preferably formed of an insulating plastic member. The charger is configured as described above. This charger has a positioning shaft 112 in a fitting hole of a block 102 in a housing 100, and a positioning shaft 112 in a positioning hole in the housing.

【formula】

The positioning shaft 112 is fixed to the housing 100 with a screw 113. On the other hand, the electrode bush 114 is fitted into the housing 100 and fixed with screws 115, which also serves to position the charger block 103. As a result, the charging section is positioned and attached to the housing 100. Next, the upper housing 62 constituting the toner storage chamber is integrally attached to the developing device 61 by heat welding or ultrasonic welding, and the toner sealed in the storage chamber is separated by the partition plate 58. It is sealed and isolated from the developing section, and when in use, by pulling out the seal, the toner flows into the developing device, and the developing device is supplied with toner. The main developing section and the corresponding section are also used as reference holes in the housing 100.

[Formula] and

The positioning shafts 119 and 120 are positioned and fitted to the [formula] part, and the positioning shaft 119 is fixed to the housing by screws 120. This developing section is therefore able to swing around the positioning shaft 119 with respect to the housing 100, and the sleeve portion (not shown) of the developing section is attached to the housing 100 to maintain an appropriate position relative to the drum. Pressure springs 121 and 122 as members
is forced by Among these, the pressure spring 121 is also provided with a contact piece as shown in part A (Fig. 14) so as to be in contact with a conductive contact piece (not shown) from the developing section for applying a bias voltage to the developing sleeve. , and this pressure spring 1
The spring board 123 is superimposed on the housing 10
It is co-tightened to 0. Also, this spring board has screw 1
24 also enables conduction between the main body side and a bias section (not shown). Next, the positioning shaft 126 having a fitting pin in the fitting hole of the cleaner section is inserted into the fitting hole of the housing 100.

【formula】

The cleaner section is positioned and fixed to the housing 100 via the formula. Also, the cleaner part 1
The other end of 4 is connected to the fitting hole of the housing 100 by a positioning shaft 127 whose fitting hole portion has a fitting pin.

It is positioned and fixed via [Formula]. Next, the drum 3 is an aluminum impact drum with an opening on one side, and a flange 43 is press-fitted into the opening side 42 and a gear 38 is press-fitted into the other side. In this drum, the flange rotational fitting part of the gear 38 is rotationally fitted to the housing, while the flange 4
A centering shaft 44, which is caulked to the centering plate 130, is fitted into the rotational fitting hole in part A of No. 3 through the fitting hole of the housing. As described above, the side plate surfaces 100a, 1 of the housing 100
Since the fitting holes drilled in 00b maintain a highly accurate positional relationship with each other, the positional relationship of the charger, cleaner, developer, etc. with respect to the drum is maintained accurately. Further, the gear part provided coaxially with the flange 43 is fitted with a counter unit 135 into a counter unit mounting hole provided in the side plate surface 100a of the casing 100, and the driven gear 136 of the counter unit 135 is fitted into the counter unit mounting hole. By meshing, a counter equipped with a speed reduction mechanism operates according to the number of rotations of the drum, and the life display rotary plate at the final stage rotates, causing the main casing 100 to rotate.
A lifespan display mark appears every moment on the lifespan display window 138 of the exterior cover 137 attached to the housing. The details are as described above. Also, this exterior cover 1
A mark 139 is attached to 37 so that it can be determined from the outside of the main body which color of toner is used in the process cartridge. By adopting the above assembly configuration,
For example, the sleeve 54 that contributes to development, the photosensitive drum 3, the rubber blade 66 of the cleaning device, etc., which will cause decisive damage to image formation if scratched, have their mounting casings turned over when each process means is assembled. Since there is no need for attachment, there is a big advantage that it can be assembled smoothly. As explained above, according to the present invention, since the positioning reference portions of the image carrier and the developing means are provided in the integrally molded process cartridge housing,
The mounting position accuracy of the image carrier and the developing means with respect to the housing can be improved, and the container of the developing means can be urged toward the image carrier around the reference hole of the housing into which the positioning member of the developing means is inserted. Because there are
The positional relationship of the developing means with respect to the image carrier can be reliably set. Further, according to the present invention, the developing means can be installed through the opening of the process cartridge housing, and the positioning member can be inserted into the reference hole from the outside of the housing so that the developing means can be supported by the container housing. Assembly of the process cartridge is also easy.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a copying machine loaded with a process cartridge to which the present invention is applied, Fig. 2 is a sectional view of the copying machine shown in Fig. 1 with the upper casing opened, and Fig. 3 is a drum cover of the cartridge. Figures 4 and 5 are side views showing the opening and closing mechanism of the drum cover, Figure 6 is a front perspective view of the process cartridge, and Figure 7 is a rear perspective view of the process cartridge. 8 is a front sectional view of the support portion of the photosensitive drum, and FIG. 9 is a front sectional view of the corona discharger.
Figure 0 is a partially enlarged sectional view of the discharger, Figure 11 is a sectional view of the developing unit, Figure 12 is a front sectional view of the developing unit on the side from which the partition plate is taken out, and Figure 13 is a sectional view of the cleaning unit. Figures 14A and 14B show assembled views of the cartridge. In the figure, 3 is a photosensitive drum, 5 is a developing device, and 5 is a photosensitive drum.
7 is a toner, 61 is a lower casing, 62 is an upper casing, 64
indicates the surface casing.

Claims (1)

[Scope of Claims] 1. A process cartridge that includes an image carrier and at least a developing unit as a process unit that acts on the image carrier, and is detachably attached to an image forming apparatus, the process cartridge comprising: and an integrally molded process cartridge housing, which is provided with an opening so that the developing means can be incorporated therein, and has respective positioning standards for the image carrier and the developing means, and a container for the developing means is positioned in the housing. a plurality of positioning members that are inserted into reference holes of the housing from both outsides of the housing with respect to the longitudinal direction of the container of the developing means to support the container of the developing means; A process cartridge comprising: a biasing member that biases a container of a developing means toward the image carrier.