CN1090658A - Process cartridge, method of assembling process cartridge, and imaging apparatus - Google Patents

Abstract

The present invention provides a process cartridge mountable in an image forming apparatus, which includes an image carrier mounted on an axial end of the image carrier so as to contact an electrical contact of the image forming apparatus to electrically ground the image carrier The conductive member and the opening part close to the laser light path blocking device in the imaging device. The opening member opens the laser light path when the process cartridge is installed in the image forming apparatus. The opening member is mounted on the other axial end of the image carrier apart from the conductive member.

Description

The present invention relates to a process cartridge, a method of assembling the process cartridge and an image forming apparatus having the process cartridge. Said image forming equipment may be, for example, a laser beam printer, xerographic copier, facsimile machine, word processor or the like.

In an imaging device such as a printer, a latent image is formed by selectively exposing a uniformly charged image carrier, and then the toner image is sequentially transferred to recording paper with toner to develop the latent image , thereby recording the image on the recording paper. In such devices, whenever the toner is exhausted or expired, it must be replenished with new toner. However, the operation of replenishing the toner is troublesome and always causes environmental pollution. In addition, various components must be serviced on a regular basis.

For this reason, a so-called process cartridge, in which a photosensitive drum, a charger, a developing mechanism, a cleaning mechanism, etc. are integrally housed in a cartridge casing, is detachably installed in an imaging device, so that toner can be replenished or replaced. terminated components and make repairs easier. Such process cassettes have been proposed and put into practice, for example as disclosed in U.S. Patent Nos. 3985,436; 4,500,195; 4,540,268 and 4,267,710.

When the process cartridge is installed in an image forming apparatus, the electrical contacts of the image forming apparatus are in sliding contact with the electrical contacts of the process cartridge, electrically grounding the image carrier. This sliding contact between the electrical contacts creates a load in the insertion direction of the cartridge.

On the other hand, in laser beam printers using process cassettes, in order to avoid leakage of laser light from the device other than imaging, an openable device (laser shutter) for blocking the laser light path is provided in the light path of the laser light. In order to open and close the laser shutter, the processing cartridge is provided with a projection for opening and closing the laser shutter. When the processing cartridge is inserted into the printer, the projection is close to a certain part of the blocking device to open the laser shutter. When the projection abuts against the blocking means, a load is generated in the cartridge insertion direction.

In addition, when the process cartridge is removed from the image forming apparatus, the exposed portion of the image carrier is covered with a protective cover to prevent it from being damaged. When the process cartridge is inserted into the image forming apparatus, the protective cover can be opened by abutting against a certain part of the image forming apparatus. Opening the protective cover during insertion of the process cartridge also generates a load in the direction of insertion of the process cartridge.

As described above, when a process cartridge is inserted into an image forming apparatus, various loads are generated along the cartridge insertion direction. Thus, there is a fear that some shaking tends to occur during mounting and demounting of the cassettes, thereby impairing the operational accuracy of loading the cassettes.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus which achieve stability of the process cartridge during insertion of the cartridge into the image forming apparatus.

Another object of the present invention is to provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus which can reduce some vibration of the cartridge during insertion of the process cartridge into the image forming apparatus.

Still another object of the present invention is to provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus which are miniaturized in size.

Another object of the present invention is to provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus, in which a space can be effectively used for arranging mechanisms for opening and closing laser shutters, etc., and can reduce the relative Certain vibrations of the imaging device when loading and unloading the handling cartridge.

Still another object of the present invention is to provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus, when loading and unloading the process cartridge with respect to the image forming apparatus, a load is generated at both shaft ends of the image carrier to reduce the load on the image carrier. Some of the shaking, so that the cassette is installed and removed smoothly.

Incidentally, a load is generated due to the sliding contact of the conductive member of the process cartridge with the electrical contacts of the image forming apparatus when the cartridge is loaded and unloaded with respect to the image forming apparatus. On the other hand, since the other end of the image carrier is separated from the conductive member, a load to open the laser shutter is generated.

Figure 1 is a longitudinal sectional view of an image forming apparatus equipped with a process cassette;

Figure 2 is a perspective view of an imaging device;

Figure 3 is a cross-sectional view of the process cassette;

Figure 4 is a perspective view of a process cassette;

Fig. 5 is a partial view of the left rail member;

Fig. 6 is a partial view of the right rail member;

Figure 7 is an exploded view showing the frame of the processing cassette;

Figure 8A is a longitudinal sectional view of the photosensitive drum;

Figure 8B is a transverse sectional view of the photosensitive drum;

Figure 9 is a perspective view of a conductive member in contact with a metal shaft;

Figure 10 is a view of the charging roller and its bearing;

Figure 11 is an exploded perspective view showing the overlapping relationship between the swelling sheet and the toner leak-proof seal;

Figure 12 shows the positional relationship between the developing blade, the toner leak-proof seal and the expansion sheet;

Fig. 13A is a sectional view along line A-A in Fig. 11;

Fig. 13B is a sectional view along the line B-B in Fig. 11;

Figures 14A and 14B show the situation where the expansion sheet is bent;

Fig. 15 is an enlarged sectional view showing a situation where a sharp rib penetrates into a developing blade;

Fig. 16 is a sectional view showing an adhesive bump for a discharge wire;

Fig. 17A shows the situation that the adhesive agent of bonding discharge wire bulges;

Figure 17B shows that the raised adhesive is smoothed out; and

Figure 17C shows the situation where the seal is added;

Figure 18A shows a discharge wire without bending; Figure 18B shows a curved discharge wire;

Figure 19 shows the situation that the cover film is pulled out from the processing cassette obliquely;

Figure 20 is a graph showing the relationship between the cover film and the toner leak-proof seal when the cover film is pulled out obliquely;

Fig. 21 is a projected view showing a tear-proof sheet provided on the toner leak-proof seal at a distance from one side of the toner leak-proof seal;

Figure 22 shows various sizes of photosensitive drum, developing sleeve and charging roller;

Figure 23 shows various sizes of charging rollers;

Figure 24 is a plan view showing the toner leak-proof seal and the partitions at both ends of the cleaning blade;

Figure 25 is a perspective view showing toner leak-proof seals and partitions at both ends of the cleaning blade;

Fig. 26 is a view illustrating a method of mounting the toner leak-proof seal on the end of the cleaning blade;

Fig. 27 is a view illustrating the demoulding method of the developing frame;

Fig. 28 is a view illustrating a cleaning frame demoulding method;

Figure 29 is a step diagram of connecting the toner frame with the developing frame using ultrasonic welding;

Figure 30 is a view showing positioning bosses and fitting holes formed on and inside the toner frame and the developing frame in the lateral direction;

Figure 31 is a view showing positioning bosses and fitting holes formed longitudinally on and inside the toner frame and the developing frame;

Fig. 32A shows the situation that the toner frame is mounted on the mounting board; Fig. 32B shows the situation that the cleaning frame is mounted on the mounting board;

Figure 33 shows the steps of installing the toner frame by an automatic device;

Figure 34 shows the steps of installing the cleaning frame by an automatic device;

Figures 35 and 36 show the situation or structure in which the photosensitive drum does not contact the table when the cleaning frame is placed on the table;

Figure 37 shows a structure in which the developing sleeve is not in contact with the table when the toner developing frame is placed on the table;

Fig. 38 is a partially exploded perspective view showing a method of connecting the toner frame and the cleaning frame with connecting members;

Figure 39A is a perspective view when the connector is installed; Figure 39B is a sectional view when the connector is installed;

Fig. 40 is a partial perspective view of the left end face of the processing cassette;

Fig. 41 is a longitudinal sectional view of the process cassette loaded into the image forming apparatus;

Figures 42-45 are partially enlarged cross-sectional views of the processing cassette loaded into the imaging device;

Fig. 46 is a partially enlarged sectional view when the process cartridge is detached from the image forming apparatus;

Figure 47 is a perspective view of a switching laser shutter mechanism;

Figure 48 is a perspective view of a grip with transverse ribs;

Figure 49 is a perspective view of the grip portion being grasped by hand;

Figure 50 shows a perspective view of a grip with grooves;

Figure 51 shows a perspective view with a raised grip;

Figure 52 is a partial perspective view showing the positions of the contacts on the process cartridge;

Figure 53 is a plan view showing the positions of the contacts on the imaging device;

Fig. 54 is a sectional view showing the relationship between the contact and the contact pin;

Figure 55 is a detection circuit for detecting the remaining amount of toner;

Figure 56 is a diagram showing the relationship between the toner amount and the remaining toner amount detection voltage;

Fig. 57 is a circuit for checking and processing cassette installation with an inverter in an embodiment of the present invention;

Figure 58 is a circuit installed in a digital signal inspection processing cassette;

Figure 59 is a functional block diagram of a control device;

Figure 60 is an exploded perspective view showing the internal structure of the cleaning frame;

Figures 61 and 62 are views of bearings used for the charging roller in another embodiment;

Figure 63 is a perspective view of a bearing used for a charging roller in yet another embodiment;

Figure 64 is a mechanism for preventing contact deformation in another embodiment;

Figure 65 is a mechanism for preventing contact deformation in another embodiment;

Figure 66 is an embodiment where the second rib on the developing frame is sharpened;

Fig. 67A is the view that discharge wire is bent into a semicircle;

Fig. 67B is the view that discharge wire is bent into trapezoid;

Figure 68 is an embodiment with an opening on the developing frame, and inserting the discharge wire into the opening can prevent the discharge wire from floating;

Fig. 69 is an embodiment in which there is a round hole on the developing frame, and the discharge wire is inserted into the round hole to prevent the discharge wire from floating.

First, a process cartridge and an image forming apparatus using the process cartridge according to a first embodiment will be described with reference to the drawings.

(The following is a general description of process cartridges and imaging devices incorporating them):

First, the overall structure of the image forming apparatus will be described. 1 is a longitudinal sectional view of a laser copier equipped with a process cartridge according to an aspect of the present invention, FIG. 2 is a perspective view of the laser copier, FIG. 3 is a cross-sectional view of the process cartridge, and FIG. 4 is a perspective view of the process cartridge .

As shown in Fig. 1, in the image forming apparatus A, the image from the optical system 1 corresponding to the image information is irradiated on the photosensitive drum so that a latent image is formed on the photosensitive drum (as a kind of image carrier), and the latent image is formed by The developer (hereinafter referred to as "toner") develops to form a toner image. While forming the toner image, the conveying device 3 sends the recording medium 2 to the image forming station of the process cartridge B, and the image forming station transfer device 4 transfers the toner image formed on the photosensitive drum. Printed on the recording medium 2. Then, the recording medium 2 is sent to a fixing device 5, where the transferred toner image is fixed on the recording medium. Next, the recording medium is sent to the output area 6 .

As shown in Fig. 3, in the process cartridge B provided with the image forming station, a charging device 8 uniformly charges a rotating photosensitive drum (an image carrier) 7. Image light from optical system 1 passes through developing device 10 to develop the latent image into a visible toner image. Then the toner image is transferred onto the recording medium 2 . In addition, the cleaning device 11 removes residual toner remaining on the photosensitive drum 7 after transfer.

The process cartridge B comprises a toner frame 12 as a first frame with a toner storage, a developing frame 13 as a second frame with a developing sleeve, and a photosensitive drum 7, a cleaning device 11 and the like. The cleaning frame 14 as the third frame. In Fig. 2, reference numeral 15a designates an operation section in which a copy number setting key, a density setting key, a trial printing key, a cartridge replacement indicator (to be described later) and the like are provided.

The respective components of the image forming apparatus A and the process cartridge B mounted thereon will be fully described below.

{imaging equipment}:

The optical system, conveying means, transfer means, fixing means and cartridge mounting means of the image forming apparatus A will be described in order.

(optical system):

The optical system 1 irradiates image light onto the photosensitive drum 7 based on image information from an external device. As shown in FIG. 1, the optical system includes an optical unit 1a including a polygon mirror 1b, a scanning motor 1c, a focusing lens 1d, a mirror 1e and a laser diode 1f, and the optical unit is located in a frame 15 of the apparatus A.

When an image signal from an external device such as a computer, a word processor, and the like (ie, the host computer 62 in FIG. 59 ) arrives, the laser diode 1f emits light according to the image signal, and the light is emitted to the polygon as image light. Mirror 1b. The scanning motor 1c makes the polygon mirror 1b rotate at a high speed, and the image light reflected by the polygon mirror is irradiated on the photosensitive drum 7 through the focusing lens 1d and the reflector 1e, so the image light is selectively exposed on the surface of the photosensitive drum 7 and then on the photosensitive drum 7. A latent image corresponding to image information is formed on the drum 7 .

(Recording medium conveying device):

Next, a conveying device 3 for conveying or feeding a recording medium (eg, OHP sheet, film, or the like) 2 will be described. The delivery device 3 in the illustrated embodiment can either manually feed paper or use a box to feed paper. As shown in FIG. 1, at the time of manual paper feeding, one or more sheets of recording medium 2 are placed on the paper supply tray 3a, and then the image forming operation is started. The recording medium 2 in the paper feed tray 3a is fed into the image forming apparatus by a pickup roller 3b. When multiple recording media 2 are placed in the paper supply tray, a pair of separation rollers 3c1, 3c2 will separate and transport the recording media one by one until the frontmost recording media withstands the gap between the pair of registration rollers 3d1, 3d2. The pair of registration rollers 3d1, 3d2 are rotated according to the image forming operation to send the recording medium 2 to the image forming station. After image formation, the recording medium 2 is sent to a fixing device 5, and then to a delivery area 6 by an intermediate conveying roller 3e and a pair of delivery rollers 3f1, 3f2. A guide rail 3g that guides the recording medium 2 is located both between the fixing device and the intermediate conveying roller and between the intermediate roller and the paired output roller.

The paper supply tray 3a includes an inner member 3a1 and an outer member 3a2. The inner part 3a1 is located inside the outer part 3a2 when not in operation. As shown in FIG. 2 , the outer part 3 a 2 constitutes a part of the device frame 15 .

For carton paper conveying, there is a placement area (as shown in FIG. 1 ) for placing a carton 3h in the lower part of the frame 15 . When the paper is not fed manually, the recording medium 2 located in the paper tray 3h in the placement area is taken out one by one from the uppermost piece of the medium 2 by the rotating pick-up roller 3i and feed-in roller 3j and sent to the paired registration roller 3d1 , 3d2. On the downstream side of the pair of registration rollers 3d1, 3d2, the recording medium is conveyed in the same manner as manual paper feeding. The sensor 3k is used to detect the presence or absence of the recording medium 2 in the cassette 3h.

(transfer device):

As shown in FIG. In particular, the recording medium 2 is abutted against the photosensitive drum 7 of the process cartridge B mounted on the mounting device (described below) by the transfer roller 4, and the polarity is opposite to that of the toner image on the photosensitive drum 7. A voltage is applied to the transfer roller 4 (in the embodiment, a DC current controlled by a DC voltage of about 1000 V) to transfer the toner image on the photosensitive drum 7 to the recording medium 2.

(fixing unit):

The fixing device 5 fixes the toner image transferred onto the recording medium 2 by applying voltage to the transfer roller 4 to the recording medium 2 . As shown in FIG. 1 , the fixing device includes a rotating driving roller 5a and a driven fixing roller 5b adjoining the driving roller 5a and including a heater 5c. When the recording medium 2 on which the toner image is transferred in the image forming station passes between the driving roller 5a and the fixing roller 5b, the recording medium is subjected to the pressure generated by the abutment between the rollers 5a, 5b and the fixing roller 5b The heat generated by the heating, and thus the transferred toner image is fixed on the recording medium 2 .

(cassette mount):

Inside the image forming apparatus A, a cartridge mounting device for mounting the process cartridge B is located. The process cartridge B can be installed or removed by opening the opening/closing cover 16 . The upper portion of the frame 15 is rotatably fitted with an opening/closing cover 16 via a hinge 16a. As shown in Figures 5 and 6, a left rail 17 and a right rail 18 are attached to the inner side walls. The guide rails 17, 18 have first guide rails 17a, 18a inclined forward and downward, second guide rails 17b, 18a located above the first guide rails, and second guide rails 17b, 18b located above the first guide rails. The guide rails 17a, 17b and 18a, 18b are arranged symmetrically. Bearing housings 17c, 18c (described below) for supporting the drum bearings of the process cartridge B are formed on the ends of the first rails 17a, 18a, respectively, and intermediate steps 17b1, 18b1 are formed on the second rails 17b, 18b, respectively.

The left guide 17 has a cartridge swing stabilizing guide 17d positioned above the second guide 17b. The right guide rail 18 has a shutter cam 18d for opening and closing the drum shutter 35 of the process cartridge B located above the second guide rail 18b.

A pressure member 19 is located above the swing stabilizing rail 17d and the shutter cam 18d, and biases the mounted process cartridge B downward via a torsion spring 19a. The abutment 20 for positioning the process cartridge B is located on the front side (front side in the cartridge insertion direction) of the left and right guide rails 17 , 18 .

After the opening/closing cover 16 is opened, the process cartridge B is loaded into the image forming apparatus guided by the first and second guide rails 17a, 18a, 17b, 18b of the left and right guide rails 17,18. Installation of the process cartridge will be described after explaining the structure of the process cartridge.

{Processing cassette}

The components of the process cartridge B incorporated in the image forming apparatus will be described below.

The processing cartridge B comprises an image carrier and at least one processing device. The processing device may be a charging device for charging the surface of the image carrier, a developing device for developing a latent image on the image carrier to form a toner image, or a cleaning device for removing residual toner left on the image carrier and similar devices. As shown in Figure 3, the process cartridge B of the embodiment includes a charging device 8, an exposure area 9, a developing device 10 for developing with toner and a cleaning device 11, which are all arranged around an electrophotographic photosensitive drum 7 as an image carrier. , the above-mentioned means are housed in a housing composed of a toner frame 12, a developing frame 13 and a cleaning frame 14 to form a process cartridge B unit detachably mounted on the frame 15 of the image forming apparatus.

The photosensitive drum 7, the charging device 8, the exposure area 9, the developing device 10, the cleaning device 11 and other parts for processing the cartridge B will be described in detail below.

(photosensitive drum):

The photosensitive drum 7 in the embodiment includes a cylindrical drum base 7a made of aluminum and an organic photosensitive layer 7b covering the peripheral surface of the drum base. As shown in Figure 7, when the photosensitive drum 7 is mounted on the cleaning frame 14 and the driving force of the image forming device drive motor 71 (see Figure 59) is transmitted to the helical gear 7c (see Figure 8A) mounted on the photosensitive drum 7-longitudinal end , the drum 7 is rotated in the direction of the arrow shown in FIG. 1 according to the image forming operation.

As shown in the longitudinal sectional view in Fig. 8A, the boss 7b1 of the gear flange 7b mounted on the photosensitive drum-longitudinal end is inserted into the bearing 14a of the frame 14, and the metal shaft (iron shaft in the embodiment) 21 is inserted into the The photosensitive drum 7 can be rotatably mounted on the cleaning frame 14 by fixing the shaft 21 in the hole on the resin helical gear 7c at the other end of the drum on the frame 14. A shaft 21 having a shaft body 21a and a flange 21b is mounted on the frame 14 by screwing the flange 21b to the frame 14 . The gear flange 7d comprising a spur gear transmits the rotational force from the image forming apparatus obtained by the photosensitive drum 7 via the helical gear 7c to the transfer roller 4 to rotate the roller 4.

The metal shaft 21 is a conductive member, and another conductive member 22 (made of phosphor bronze in the embodiment) is in contact with the inner surface of the aluminum drum base 7a at the end where the metal shaft 21 is inserted into the photosensitive drum, so that when the metal The shaft 21 is in contact with the conductive member 22 when inserted into the photosensitive drum. The photosensitive drum 7 is thereby grounded to the image forming apparatus via the conductive member 22 and the metal shaft 21, as will be described later. As shown in FIG. 9, the conductive member 22 is fixed on the boss 7c2 on the side of the flange 7c1 of the helical gear 7c. The conductive member 22 has a hole or opening 22a through which the metal shaft 21 is inserted. A resilient contact 22b also protrudes into the opening 22a. The metal shaft 21 abuts and contacts the contact piece 22b when inserted into the opening. A pair of claws 22c protrude from the conductive member 22 along the left and right directions. The claws 22c come into contact with the inner surface of the photosensitive drum 7 when the flange 7c1 is inserted into the photosensitive drum 7 .

During the image forming operation, the surface of the photosensitive drum 7 is uniformly charged by the charging roller 8 to which the superimposed voltage of AC and DC is applied while the photosensitive drum 7 is rotated. At this time, in order to uniformly charge the surface of the photosensitive drum 7, it is preferable to apply voltage to the charging roller 8 by superimposing AC and DC voltages and increase the frequency of the AC voltage. However, when the AC voltage frequency exceeds 200 Hz, so-called "charging noise" will be generated due to the vibration of the photosensitive drum 7 and the charging roller 8.

When an AC voltage is applied to the charging roller 8, an electrostatic attraction force is generated between the photosensitive drum 7 and the charging roller 8, and the attractive force becomes stronger at the maximum and minimum values of the AC voltage, so that the charging roller 8 is attracted to the photosensitive drum 7 and becomes elastic. out of shape. The electrostatic attractive force is weak at the middle value of the AC voltage, and at this time, the charging roller 8 is separated from the photosensitive drum 7 by the restoring force of the elastic deformation. Thus, the photosensitive drum 7 and the charging roller 8 vibrate at a frequency twice the frequency of the applied AC voltage. When the charging roller 8 is attracted to the photosensitive drum 7, the rotation of the roller and drum is hindered, and vibrations are generated due to stick-slip (such as that produced by rubbing wet glass with a finger); this vibration produces charging noise.

According to the embodiment, as shown in the sectional views of FIGS. 8A and 8B , in order to reduce the vibration of the photosensitive drum 7 , a filler 7 e made of a rigid body or an elastic body is installed in the longitudinal middle of the photosensitive drum 7 . The material of the filler 7e may be metal such as aluminum, brass, or artificial stone such as cement, gypsum, or rubber such as natural rubber and the like. In consideration of productivity, workability, weight and cost, the material of the filler is preferably selected from the above-mentioned materials. In an embodiment, the filler piece 7e made of aluminum weighs about 120 g.

The shape or profile of the filler 7e can be a solid column or a hollow column (as shown in FIG. 8 , the filler in the embodiment is a solid column). For example, the outer diameter of the filler 7e is 100 [mu]m smaller than the inner diameter of the photosensitive drum 7, and the filler 7e is inserted into the hollow drum base 7a to fit the filler into the photosensitive drum. At this time, the maximum gap between the drum base 7a and the filler 7e is 100 μm, and an adhesive (such as cyanoacrylate, epoxy resin or the like) is added to the outer surface of the filler or the drum base 7a. The inner surface of the drum base 7a can bond the filler 7e to the inner surface of the drum base 7a.

As described above, the photosensitive drum 7 can be rotated smoothly after the filler 7e is incorporated in the photosensitive drum 7, which eliminates the vibration caused by the rotation of the photosensitive drum during the image forming operation. Thus, charging noise can be suppressed even if the frequency of the AC voltage applied to the charging roller 8 is increased.

(charging unit):

The charging device is used to charge the surface of the photosensitive drum 7 . In the embodiment, the contact type charging method described in laid-open Japanese Patent No. JP63-149669 is used. As shown in FIG. 10, the charging roller 8 is rotatably mounted on the cleaning frame 14. As shown in FIG. The charging roller 8 includes a metal roller shaft 8a, an elastic conductive layer surrounding the metal roller shaft, a high-resistance elastic layer surrounding the conductive layer, and a protective film surrounding the high-resistance layer. The elastic conductive layer is composed of an elastic rubber layer made of EPSM or NBR dispersed with carbon powder, and its function is to apply a bias voltage to the roller shaft 8a. The high-resistance elastic layer is composed of urethane rubber dispersed with a small amount of conductive fine powder such as carbon powder, and functions to limit the photosensitive Drum 7 leakage current to prevent a sharp drop in bias voltage. The protective film is made of N-methyl methoxy nylon, and its function is to prevent the surface of the photosensitive drum 7 from being worn when the plastic material of the conductive elastic layer and/or the high resistance elastic layer contacts the photosensitive layer.

The roller shaft 8a is slidably mounted on the frame 14 towards the photosensitive drum 7 through the bearings 23 and 24, and the spring 25 biases the bearing to the photosensitive drum 7 so that the charging roller 8 contacts the photosensitive drum 7.

During the image forming operation, the rotation of the photosensitive drum 7 drives the charging roller 8 to rotate, and at the same time, the superimposed AC and DC voltages are applied to the charging roller 8 as described above, so that the surface of the photosensitive drum 7 is uniformly charged. The metal contact member 26 having elasticity is in contact with one end of the metal roller shaft 8a so that the voltage from the image forming apparatus can be applied to the charge roller 8. As shown in FIG.

The adjustment piece 14b that prevents the deformation of the contact member 26 is formed on the cleaning frame 14, so that even if a force directed to the left side in FIG. The contact piece 26 is withstood, so the piece 26 will not be elastically deformed. Since the restricting member 14 b restricts the axial movement of the charging roller 8 (towards the left in FIG. 10 ), the charging roller 8 is always held on the photosensitive drum 7 .

The bearing 24 contributes to the positioning of the other end of the charging roller 8 . As shown in FIG. 10, the bearing 24 has a hook claw 24a integrally connected thereto. The other end of the roller shaft 8a of the charging roller 8 bears against the claw 24a so that the axial movement of the charging roller 8 to the right ( FIG. 10 ) is restricted. The bearing 24 is made of polyacetal resin (POM) with good wear resistance, so that the bearing has good sliding property relative to the metal roller shaft 9a.

As described above, both ends of the roller shaft 8 a abut against the anti-friction bearing 24 and the contact member 26 respectively to limit the axial movement of the charging roller 8 so that the roller shaft remains out of contact with the frame 14 . If the end of the roller shaft 8a directly abuts against the frame 14 to limit the axial movement of the charging roller 8, the frame 14 must be made of a material that has good wear resistance relative to the metal roller shaft 8a, such as polyphenylene oxide resin (PPO). . Conversely, as shown in the embodiment, if the roller shaft 8a is not in direct contact with the frame 14, it is not necessary to enhance the wear resistance of the frame 14. Therefore, in the embodiment, instead of PPO, cheaper polystyrene resin (PS) is used as the material of the frame 14 in order to reduce the manufacturing cost of the process cartridge B.

The material of the bearing 24 is not limited to polyphenol resin, but may also be other materials such as nylon and other materials having high wear resistance relative to the metal roller shaft 8a.

According to an embodiment, the voltage applied to the charge roller 8 to charge the photosensitive drum 7 has an AC component Vpp of about 1800V and a DC component VDC1 of about −670V, and constant current control can be realized.

(exposure area):

The exposure zone 9 functions to expose the photosensitive drum to image light from the optical system 1 to form an electrostatic latent image on the photosensitive drum 7 uniformly charged by the charging roller 8 . As shown in FIG. 4, the exposure area is constituted by an opening 9 formed in a top surface between the developing frame 13 and the cleaning frame 14 through which image light passes. That is, the exposure area 9 is constituted by the rectangular notch 9a on the top surface 13r of the developing frame 13 and the top wall 14n of the cleaning frame 14 covering a part of the notch 9a.

(developing unit):

The developing device uses toner to make the electrostatic latent image previously formed on the photosensitive drum by exposure into a visible toner image. Although the image forming apparatus A can use both magnetic toner and non-magnetic toner, the process cartridge B loaded into the image forming apparatus in the illustrated embodiment contains a one-component magnetic developer magnetic toner.

The magnetic toner used in the developing operation uses a polystyrene resin as a binder resin, but preferably a styrene acrylic resin. The coloring material that can be added to the magnetic toner can be commonly used carbon black, copper phthalocyanine, iron black or similar materials.

The magnetic fine particles contained in the magnetic toner are made of materials that can be magnetized in a magnetic field, and these materials may be ferromagnetic metal powders such as iron, cobalt, nickel, or alloys or compounds such as magnetite or ferrite.

As shown in FIG. 3, a developing device 10 that uses toner to form a toner image has a toner storage 10a for storing toner and a toner storage 10a for sending out toner in the toner storage. The conveying member 10b rotates in the direction indicated by the arrow. A thin layer of toner is formed on the developing sleeve by feeding out the toner and rotating the developing sleeve 10d containing a magnet 10c. When this toner layer is formed on the developing sleeve 10d, triboelectric charges sufficient to develop the electrostatic latent image on the photosensitive drum 7 are obtained due to friction between the toner and the developing sleeve 10d. A developing blade for adjusting the thickness of the toner layer is abutted against the surface of the developing sleeve 10d.

In an embodiment, the applied developing bias is an AC component Vpp of about 1600V and a DC component VDC2 of about −500V. In the relationship between the DC component VDC2 of the developing bias voltage and the aforementioned direct component VDC1 of the charging bias voltage, if the value (VDC1-VDC2) becomes greater than -50V (increasing towards the positive direction), the image will be blurred fault.

A toner storage 10 a and a toner conveying member 10 b are formed on a toner frame 12 , while a developing sleeve 10 d and a developing blade 10 e are mounted on a developing frame 13 . The longitudinal contacts of the frames 12.13 are welded to each other by ultrasonic welding, so that the frames are joined together.

The developing sleeve 10d with the toner layer and the photosensitive drum 7 are positioned with a small gap (about 250 µm) therebetween. For this reason, in the embodiment (as shown in FIG. 11 ), the outer diameter of each contact ring 10f is larger than the outer diameter of the developing sleeve 10d by a value corresponding to the above-mentioned gap and is installed near the two shaft ends of the developing sleeve 10d for adjustment. The area outside the toner forming area. The contact ring abuts against a portion of the photosensitive drum 7 other than the latent image forming area.

A (helical) gear 10g is mounted on an axial end of the developing sleeve 10d so that the gear 10g can rotate together with the developing sleeve 10d. When the developing frame 13 is connected to the cleaning frame 14, the gear 10g meshes with the helical gear 7c of the photosensitive drum 7, so that the rotation of the photosensitive drum 7 rotates the developing sleeve 10d. Further, the gear 10g meshes with a gear (not shown) connected to the toner conveying member 10b to transmit the rotational force of the photosensitive drum 7 to the toner conveying member 10b.

In the image forming operation, the rotation of the toner conveying member 10b having the above-mentioned structure sends the toner in the reservoir 10a to the developing sleeve 10d, and the toner having a constant thickness is formed on the developing sleeve by the developing blade 10e. layer, and then the toner on the developing sleeve is transferred onto the electrostatic latent image formed on the photosensitive drum 7 . The toner layer can be formed on the developing sleeve 10d only by applying toner to a carbon-coated area of the developing sleeve 10d, for (a) the photosensitive layer area along the longitudinal (axis) direction of the photosensitive drum 7, (b) The relationship between the charging area produced by the charging roller 8 and (c) the toner forming area on the developing sleeve 10d should be selected as (a)>(b)>(c).

The toner in the reservoir 10a must be prevented from leaking from between the developing sleeve 10d and the developing frame 13. For this reason, as shown in FIG. 11, in the embodiment, the two longitudinal ends of the opening 13a that is located in the developing frame 13 and allows the toner to pass through to be sent to the developing sleeve 10d are provided with a toner leak-proof elastic seal 10h. , An elastic expansion sheet 10i is provided below the opening 13a that is in contact with the entire length of the developing sleeve 10d.

Each toner leak-preventing seal 10h is equal to the thickness of the step on the lower edge 13o of the developing frame 13, so that when the toner leak-preventing seal 10h is stuck to the developing frame 13, the upper surface of the seal 10h is in contact with the developing frame 13. The lower edge is as flat as 13o. The expander 10i is adhered to the upper surface of the lower edge 130 with double-sided tape (not shown). The (longitudinal) length of the expansion sheet 10i is greater than the longitudinal length of the opening 13a, and the two longitudinal ends of the expansion sheet overlap with the toner leak-proof seal 10h, and a free edge of the expansion sheet in the width direction is pressed against it along its length with an appropriate abutting force. The peripheral surface of the developing sleeve 10d.

The overlapping relationship between the swelling sheet and the toner leak-proof seal will be described in detail below. As shown in FIG. 12, since the developing blade 10c is about 13 mm thick, both longitudinal ends of the developing blade 10e cannot overlap with the toner leak-proof seal 10h, which causes a gap between the end of the developing blade and each toner seal. 10k for a small gap. And the toner leakage preventing seal 10h overlaps with the axial region of the expansion sheet 10i outside the gap 10k.

Therefore, when the toner layer is formed on the developing sleeve 10d, the toner tm sticks to the developing sleeve 10d in a convex shape through the gap 10k. Since the toner leak-proof seal 10h is provided in the rotating toner tm area, the toner tm is sucked into the toner storage 10a through the expansion sheet 10i, thereby preventing the toner from leaking out of the cartridge.

Fig. 13A is a cross-sectional view along line A-A in Fig. 11, and Fig. 13B is a cross-sectional view along line B-B in Fig. 11 . As shown in FIG. 13A, the toner leak-preventing seal 10h and the expanding sheet 10i are in close contact with each other without being bent in the overlapping region, and are parallel to each other. As shown in Figs. 14A and 14B, if the curved expansion sheet 10i is not in close contact with the toner leakage preventing seal, toner may leak from the gap between the seal and the expansion sheet. However, since the swelling sheet 10i is not bent and is in close contact with the toner seal 10h in the embodiment, there is no risk of toner leakage.

In the embodiment, the upper surface of the toner leak-preventing seal 10h defines the contact angle between the free edge of the expansion sheet 10i and the peripheral surface of the developing sleeve 10d, and there is no precision deviation in the upper surface of the toner leak-preventing seal. Since the expansion sheet 10i remains straight in use, the contact angle of the expansion sheet 10i remains unchanged for a long time, so the toner stored in the toner storage 10a is difficult to leak from between the expansion sheet 10i and the developing sleeve 10d. .

Still another possibility for toner leakage is toner leakage from between the developing blade 10 e and the developing frame 13 . In order to avoid this defect, as shown in FIGS. 3 and 14, in the embodiment, three longitudinal ribs 13b, 13c, 13d are formed in the part where the developing frame 13 abuts against the developing blade 10e, so that the first and second ribs 13b , 13c abut against the developing blade 10e, and the second rib 13d abuts against the metal plate for mounting the developing blade 10e, that is, the blade mount 10j. The free edge of the second rib 13c which abuts against the developing blade 10e is sharpened, and the second rib 13c is sharpened when the first rib 13b abuts against the developing blade 10e and the third rib 13d abuts against the blade mount 10j A developing blade made of rubber with a thickness of 1.3mm is inserted into the edge.

The sharp side of the second rib 13c is bent, and the middle portion of the side protrudes slightly from both ends of the side in the longitudinal direction. When the developing blade 10e is mounted on the developing frame 13, since the parts of the blade mounting parts 10j near the two longitudinal sides are screwed, the longitudinal middle part of the developing blade mounted on the blade mounting parts may be misaligned. shift. However, according to the above-mentioned structure, even if the middle part of the blade is offset, since the edge of the second rib 13c is bent into a shape in which the middle part protrudes from both ends (in a process cartridge capable of recording images on A4 size paper, the protrusion The output is preferably 0.1-0.5mm), so the rib 13c can ensure that its entire longitudinal edge is inserted into the developing blade 10e. Accordingly, there is no gap between the developing frame 13 and the blade 10e, thereby preventing toner leakage from between the blade and the developing frame.

When the toner leaks out due to the gap created between the second rib 13c and the developing blade 10e, the third rib 13d abutting against the blade mount 10j prevents the toner from leaking. Since the contact area between the second rib 13c and the developing blade 10e is offset (that is, misaligned) by an amount corresponding to the thickness of the developing blade 10e relative to the contact area between the third rib 13d and the blade mounting member 10j, It is difficult for toner to leak out of the cartridge from two contact areas between the second rib 13c and the developing blade 10e and between the third rib 13d and the blade mount 10j.

In the developing device 10 shown in the embodiment, there is a remaining toner detecting mechanism for detecting remaining toner in the toner storage 10a. As shown in FIGS. 11 and 15, the mechanism includes a metal discharge wire 27 located on the passage from the toner reservoir 10a to the developing sleeve 10d and at the connection area between the toner frame 12 and the developing frame 13. As shown in FIG. A voltage is applied between the discharge wire 27 as a first electrode and the developing sleeve 10d as a second electrode. At this time, if there is toner between the electrodes, the electrostatic capacity between the electrodes increases, and conversely, if there is no toner, the electrostatic capacity between the electrodes decreases. Thus, the remaining amount of toner can be detected by detecting the change in the electrostatic capacity by the control section 60 (see Fig. 59). The "toner-free" state can be determined by comparing the electrical signal representing the electrostatic capacity with a predetermined reference value. When the control section 60 detects the "toner empty" state, a lamp for prompting replacement of the process cartridge is illuminated to notify the operator that the process cartridge B needs to be replaced. A specific circuit for detecting the remaining amount of toner will also be described below.

As for the connection area between the toner frame 12 and the developing frame 13, since the vertical connection area is welded, the toner will not leak from the vertical connection area. However, as shown in FIG. 11, since the toner of the toner storage 10a in the process cartridge B is prevented from leaking, the cover film 28 hermetically covers the opening 12e located on the toner frame 12, and a part of the cover film 28 The free end is exposed outwardly through the transverse connection area (between the frames 12, 13) so that the operator can pull the free end of the cover film 28 to open the opening 12e during work, so that the transverse connection area cannot be welded. Therefore, in order to prevent the toner from leaking from the lateral connection area between the toner frame 12 and the developing frame 13, a toner leak-proof seal 29 is provided at the lateral connection area.

As mentioned above, since a voltage is applied to the discharge wire or line 27, one end of the discharge wire 27 must protrude outward through the connection area between the frames 12, 13, and there is a contact 27a at the protruding end of the discharge wire. For this purpose, the discharge wire 27 must protrude outward through the lateral connection area (between the toner frame 12 and the developing frame 13 ) where the toner leak-proof seal 29 is bonded. As shown in Figure 16, in order to install the discharge wire 27 in the above-mentioned manner, the adhesive 30 such as silicone is coated on the surface of the groove 13e on the developing frame 13 connection area, and then the discharge wire is inserted into the groove to discharge the wire. The wire 27 is stuck to the developing frame 13. As shown in FIG. 16, when the discharge wire 27 is inserted into the groove 13e, the adhesive 30 coated on the surface of the groove 13e protrudes from the groove and expands. If the adhesive 30 is solidified in the expanded state, the seal 29 cannot completely come into close contact with the developing frame 13 even though the toner leak-proof seal 29 sticks to the frame 13, so a gap 31 is often produced. Although the gap 31 is small, toner may leak through the gap 31 because the toner contains very fine particles.

In order to eliminate this defect, in the embodiment shown in FIG. 17A, after the discharge wire 27 is inserted into the groove 13e with the adhesive 30, a rod or the like as shown in FIG. On and along the discharge wire (that is, to completely cover the discharge wire 27) to flatten the adhesive expanded from the groove 13e. In this way, as shown in FIG. 17C, when the toner leak-proof seal 29 is stuck to the frame 13, the seal 29 can be in close contact with the (attached) surface of the developing frame 13 without any gap, thereby completely avoiding toner leakage. Agent leaks. As shown in FIG. 17B , new adhesive can be added on top of the flattened expanded adhesive 30 and completely cover the discharge wire 27 .

The contact point 27a of the discharge wire 27 is exposed to the outside. Therefore, there is a high possibility that the exposed portion of the discharge wire 27 will hit something by mistake during the process of attaching and detaching the handling cartridge B by the operator. As shown in FIG. 18A, since the toner leak-proof seal 29 having a thickness of about 4 mm is made of foamed urethane and has elasticity, when the exposed portion of the discharge wire 27 bumps against something, the discharge wire 27 is likely to be removed from the developer. Frame 13 floats up. At the same time, a small gap 32 occurs between the frame 13 and the discharge wire 27 to cause toner leakage. In order to avoid this deficiency, as shown in the embodiment of FIG. 18B, there is an L pointing from the developing frame 13 to the toner frame 12 on the discharge wire 27 located in the connection area between the toner frame 12 and the developing frame 13. Type of curved portion 27b. At the bent portion 27b, since the 4 mm thick seal 29 is compressed upward by about 1 mm, no elastic deformation occurs. Accordingly, the above-mentioned impact acts on the exposed portion of the discharge wire 27 , and the discharge wire 27 does not float from the groove 13 e of the developing frame 13 . At the same time, since the gap shown in Fig. 18A does not occur, the risk of toner leakage can also be avoided.

(toner leak-proof seal):

Next, the toner leakage preventing seal 29 will be described. Toner leak-preventing seals 29 are adhered to both longitudinal end portions of the opening 12e of the toner frame 12 with double-sided tape. As shown in FIG. 11, a tear-proof sheet 29a having a thickness of about 0.01-1mm and a width narrower than the seal 29 is attached to the upper surface of the toner leak-proof seal 29 on the side where the operator pulls out the cover film 28.

The reason for installing the tear-resistant sheet 29a is because the operator must manually pull out the cover film 28 in order to open the opening 12e of the process cartridge B in use. In this case, no problem occurs if the operator pulls the cover film 28 in the film withdrawal direction (corresponding to the longitudinal direction of the opening 12e). However, as shown in FIG. 19, when the cover film is drawn in a direction inclined at an angle α relative to the film drawing direction, as shown in FIG. 28 is narrowed or crumpled in width, the crumpled portion of the membrane will rub against the toner leak-proof seal 29 and often tear the portion of the seal 29 (hatched area). If the toner leak-preventing seal 29 is torn or torn, the toner leaks from the tear to soil the operator's hands or falls into the image forming apparatus to soil the printed recording medium.

As shown in the embodiment, when the cover film 28 is pulled out through the tear-proof sheet 29a stuck on the toner leak-proof seal 29, if wrinkles are generated when pulling out, since the seal 29 is protected by the tear-proof sheet 29a, the seal 29 will not be damaged. will be torn. Therefore, pulling out the cap film 28 does not cause toner leakage no matter in which direction.

After the tear-proof sheet 29a is installed along the width of the seal 29 on one side of the opening 12e, when the cover film 28 is pulled out, the tear-proof sheet 29a can scrape off the toner stuck on the cover film 28, which eliminates the Possibility of the operator's hands being soiled by the pulled membrane 28 .

When the toner frame 12 and the developing frame 13 were welded to each other, since the toner leak-proof seal 29 and the tear-proof sheet 29a were firmly sandwiched therebetween and were secured by the two longitudinal ends of the frames 12, 13 (Fig. 14). The upper and lower ends) are fixed so that the sheet 29a will not be detached from the seal 29. The anti-tear sheet 29a is preferably made of a material with good friction resistance to the cover film 28, such as polyethylene terephthalate or high density polyethylene.

As shown in Figure 21, when the tear-proof sheet 29a having a width smaller than the toner leak-proof seal 29 is stuck on the seal 29, the sticking position of the sheet 29a is separated from the edge 29b of the toner leak-proof seal 29 along the film drawing direction. The distance is U. Thus, when the cover film 28 is pulled out, the edge 29b scrapes off the toner stuck to the film 28 more effectively. When the distance is 5 mm or less, the tear-preventing effect on the toner leak-preventing seal 29 does not deteriorate during the process of pulling out the cover film 28 .

As described above, the width of the tear-preventing sheet 29a may be not smaller than that of the toner leak-proof seal 29 so that the sheet is adhered to the entire surface of the seal 29.

(Size of photosensitive drum and other components):

Various dimensions of the photosensitive drum 7, charging roller 8, and developing sleeve 10d in the embodiment and the positional relationship among these components will be described below with reference to FIGS. 22 and 23. FIG. However, the present invention is not limited to these examples, and other suitable dimensions and positioning relationships can also be used.

(1) The number of teeth of the helical gear 7c is 32;

(2) The diameter (D1) of the helical gear 7c is about 31.85mm;

(3) The width (W1) of the helical gear 7c is about 9.8mm;

(4) The number of teeth of the gear flange 7d is 43;

(5) The diameter (D2) of the gear flange 7d is about 32mm;

(6) The width (W2) of the gear flange 7d is about 5.6mm;

(7) The length (L1) of the photosensitive drum 7 is about 254mm;

(8) The photosensitive body on the photosensitive drum 7

The length (L2) of the coating area is about 250mm;

(9) The diameter (D3) of the photosensitive drum 7 is about 30mm;

(10) metal shaft 21 of photosensitive drum 7

The diameter (D4) is about 10mm;

(11) The length (L3) of the developing tube 10d is about 246mm;

(12) Carbon coating area on developing sleeve 10d

The length (L4) is about 216mm;

(13) The diameter (D5) of the developing tube 10d is about 16mm;

(14) The outer diameter (D6) of the contact ring 10f is about 16.5mm;

(15) The length (L5) of the contact ring 10f is about 12mm;

(16) The length (L6) of the contact ring 10f is about 9mm;

(17) Drum contact portion of contact ring 10f

The outer diameter (D7) is about 16.7mm;

(18) Drum contact portion of contact ring 10f

The thickness (E1) is about 0.3mm;

(19) Drum contact portion of contact ring 10f

The width (W3) is about 4mm;

(20) The number of teeth of the developing gear 10g is 17;

(21) The diameter (D8) of the developing gear 10g is about 18.1mm;

(22) The width (W4) of the developing gear 10g is about 8.3mm;

(23) charging bias contact 49

The length (L7) is about 7mm;

(24) charging bias contact 49

The width (W5) is about 7.8mm;

(25) charging bias contact 48

The length (L8) is about 6mm;

(26) charging bias contact 48

The width (W6) is about 9.4mm;

(27) The contact of the discharge wire 27

The diameter (D9) of 27a is about 2mm;

(28) The contact of the discharge wire 27

The width (W7) of 27a is about 15.5mm;

(29) The length (L8) of the charging roller 8 is about 251mm;

(30) Charging roller 8 charging part

The length (L9) of (rubber part) is about 225mm;

(31) The diameter (D10) of the charging roller 8 is about 12mm;

(32) The length (L10) of the roller shaft 8a is about 12mm;

(33) The diameter (D11) of the roller shaft 8a is about 6mm;

The gear 7c and the developing gear 10g here are so-called helical gears. When the gear 7c is driven by force from the image forming apparatus, the photosensitive drum 7 mounted with the gear 7c is acted upon by the thrust applied to the gear 7c. Then, the photosensitive drum 7 is displaced by the thrust along the thrust direction and abuts against the cleaning frame 14, so that the photosensitive drum is positioned along the thrust direction.

(cleaning device):

After the transfer device 4 transfers the image on the photosensitive drum 7 to the recording medium 2, the cleaning device 11 removes the toner remaining on the photosensitive drum 7. As shown in Figure 3, the cleaning device 11 includes a cleaning blade 11a which is in contact with the surface of the photosensitive drum 7 and scrapes off the toner left on the drum 7, and a cleaning blade 11a which is located at the bottom of the scraper 11a and contacts the surface of the photosensitive drum 7 for blocking the toner A dipping sheet 11b for scraping off toner, and a waste toner storage 11c for collecting the trapped waste toner. The dip sheet 11b, which is in light contact with the surface of the photosensitive drum 7, allows the waste toner on the photosensitive drum 7 to slide over, and guides the toner removed by the scraper 11a in a direction away from the surface of the photosensitive drum 7 (i.e., toward the waste toner toner storage 11c).

Similar to the developing blade 10e, the cleaning blade 11a is made of rubber or the like and is adhered to a blade mounting member 11b with a double-sided tape. The scraper mount is fixed on the cleaning frame 14 with screws. The dipping sheet 11b is stuck to the dipping sheet bonding surface (edge portion) 11c1 of the waste toner storage 11c with a double-sided tape.

It is necessary to prevent the waste toner in the waste toner storage 11c from leaking from between both longitudinal ends of the cleaning blade 11a and the opposing cleaning frame 14 . To this end, toner leak-proof seals are bonded to both longitudinal end portions of the blade 11a. However, if the toner leak-proof seal is not completely in close contact with the cleaning blade 11a, the toner may leak from the gap between the seal and the blade. Also, if the toner leak-proof seal is not in close contact with the soaking sheet adhesive surface 11c1 of the waste toner storage 11c, the toner will leak from the gap between the seal and the adhesive surface.

To avoid this disadvantage, as shown in Fig. 24, in the embodiment, the toner leak-proof seals 11e are provided on both longitudinal ends of the cleaning blade 11a. The portion where this seal 11e is provided will be described in detail below. As shown in FIGS. 24 and 25, seals 11e are adhered to both end portions of the waste toner storage 11c, while both longitudinal end portions of the cleaning blade 11a are adhered to the seals 11e. The partition 11c3 is located on an upper surface 11c2 of the waste toner storage 11c and is in contact with the corresponding seal 11e.

Next, the installation method of the toner leakage preventing seal 11e will be described. First, the cleaning blade 11a is mounted on the cleaning frame 14, and then, as shown in FIG. 26, the seal 11e is installed in such a manner that the side S2 of the seal is in close contact with the two longitudinal sides S1 of the cleaning blade 11a. In this assembly, if the width W1 of the seal 11e is greater than the distance LO between the dipstick bonding surface 11c1 and the cleaning blade 11a, a gap will appear between a low side T1 of the seal 11e and the dipstick bonding surface 11c1. This results in toner leakage. To avoid this, in an embodiment, the distance LO should be made greater than the width L1 (LO>L1) by a gap, while giving the seal 11e a compression time X. In this case, the seal 11e must be adhered to the bonding surface 11c1 of the dip sheet and the lower side T1 of the sealing 11e abuts against the shaded portion T2 of the bonding surface; as shown in the embodiment, since the partition 11c3 is provided, Waste toner does not leak when sliding along the adhesive surface of the dip sheet. Thus, the compression amount X of the seal 11e in the gap can be made substantially zero.

(frame):

Next, the frame constituting the casing of the process cartridge B will be described. As shown in FIG. 7, the casing of the process cartridge B is composed of a toner frame 12, a developing frame 13 and a cleaning frame 14. As shown in FIG. The toner frame 12 and the developing frame 13 are welded together to form a toner developing frame C. As shown in FIG. The toner developing frame C is connected to the cleaning frame 14 to form the housing of the process cartridge B in a manner described further below. The frames 12, 13, 14 in the embodiment are made of polystyrene resin and molded by injection. When the charging characteristics of the materials used for the frames 12, 13, 14 are close to those of the toner components, even if the toner rubs against the frames during image formation, abnormal charges will not be generated due to frictional electricity generation. Deterioration of image quality is prevented.

In this regard, the example shown in Table 1 below (article "Surface Polymers and Electrostatics", "Surface Thin Film Molecular Design" Series 5, published by The Surface Society of Japan, by Yuji Mutata), because the frame material polystyrene and the color The toner components, styrene propylene, are all of the same styrenic group and have similar charging characteristics, and no abnormal charge is generated even if the toner is rubbed against the frame. "Styrenic" means 60% or more styrene in the base material.

Table 1 (Charging System)

(positive end)

Silicone Elastomers with Silica Fillers

Cellulose Sponge

woven cotton

polyurethane elastomer

Styrene acrylonitrile copolymer (binder material of the toner in Examples)

Styrene Butadiene Copolymer

Polystyrene (the material of the frame in the example)

polyisobutylene

Polyurethane flexible sponge

Borosilicate glass with polished surface

PTFE

(negative terminal)

As shown in FIG. 7 , a toner storage 12 a and a toner conveying member 10 b are located in the toner frame 12 . As shown in FIGS. 3 and 4, a group of longitudinal ribs 12d formed on the outer surface of the toner frame 12 constitutes a grip portion. The ribs 12d formed on the outer surface of the toner frame 12 gradually change in width to form a complete R-shaped structure. When attaching and detaching the process cartridge B to the image forming apparatus A, since the operator can easily grasp the grip portion of the toner frame 12 without slipping, the operability of attaching and detaching the cartridge B is improved.

As shown in FIG. 7 , a developing sleeve 10 d and a developing blade 10 e are located on the developing frame 13 . As shown in FIG. 11, when installing the developing blade 10e, the blade mounting part 10j should be positioned relative to the developing frame 13 before the mounting part is fixed with screws. For this reason, a vertical boss 13g is provided on the scraper mounting part 13f of the developing frame 13, and a hole is provided on the scraper mounting part 10j to insert the positioning boss 13g, so that the mounting part can be positioned relative to the frame. 13 positioning. As shown in Figures 7 and 11, the positioning bosses 13i (as shown in Figure 11, these positioning bosses are located at the two longitudinal ends of the developing frame 13) for connecting the frame 13 to the toner frame 12 are connected from the developing frame 13. Protrude vertically on the surface 13h. The joint between the developing frame 13 and the toner frame 12 can be positioned by inserting the boss 13i into the positioning hole 12c on the toner frame 12.

In the embodiment, as shown in FIG. 27, the blade mounting surface 13f and the connecting surface 13h of the developing frame 13 should be made parallel to each other. Thus, when manufacturing the developing frame 13 by injection molding, since the boss 13g of the positioning blade and the boss 13i of positioning the toner frame are parallel to each other, after the molding operation, only the molds 33 are separated from each other in the left and right directions. Easily remove the formed frame from the mold.

As shown in FIG. 7 , the photosensitive drum 7 , the charging roller 8 , the cleaning blade 11 a of the cleaning device 11 , the soaking sheet 11 b and the waste toner storage 11 c are located on the cleaning frame 14 . When the cleaning blade 11a is attached to the cleaning frame 14 as in the above-described mounting of the developing blade 10e, both longitudinal ends of the cleaning blade-attached blade mounting member 11d are screwed to the frame 14. However, the scraper mount 11d needs to be positioned relative to the frame 14 before the screws are fastened. For this reason, as shown in Figure 28, on the scraper mounting surface 14c of frame 14, be provided with vertical positioning boss 14d, and be provided with the hole (not shown) that can insert boss 14d on scraper mounting part 11d ), so that the mount is positioned relative to the cleaning frame. In this fit, the scraper mounting surface 14c is designed to be perpendicular to the stripping direction of the mold 34 (the direction of the arrow in FIG. 28). In this way, since the projection direction of the positioning boss 14d on the scraper mounting surface 14c is parallel to the stripping direction of the mold 34, the design of the mold 34 can be simplified.

The drum shutter 35 shown in FIG. 3 is rotatably mounted on the cleaning frame 14. As shown in FIG. The drum shutter 35 is used to open and close an opening through which the photosensitive drum 7 faces the transfer roller 4 . When the process cartridge B is attached to the image forming apparatus A, the drum shutter is automatically opened and when the process cartridge B is removed from the image forming apparatus A, the drum shutter is automatically closed as described below.

(welding between the toner frame and the developing frame):

Welding between the toner frame loop 12 and the developer frame loop will now be described. The connection of the frames 12, 13 to each other is welded by ultrasonic welding. That is to say, as shown in FIG. 29, after the opening 12e of the toner frame 12 is covered by the cover film 28, the toner frame 12 is installed in the recess 75a of the receiving member 75, and then the frame 12 which is integral with the frame 12 is assembled. The detachable cover film extraction handle 12f is bent downward. After that, the developing frame 13 is overlapped with the toner frame 12, and the developing frame 13 is pressed by the pressing member 76 from above. In this state, when ultrasonic waves are applied to the toner frame 12 and the developing frame 13, the rib 13S (see FIG. interconnected.

When ultrasonic waves are applied to the frame, deformation often occurs in the width direction of the frame (shown by arrow J in Figure 29). However, in the embodiment, as shown in FIG. 11, since the developing frame 13 is provided with the longitudinal rib 13t, and the blade mounting member 10j mounted on the developing frame is made of a metal plate, the developing frame has sufficient strength. Resists deformation. In addition, since there are no reinforcing ribs on the toner frame 12, the toner frame has low strength and is often easily deformed. However, in the embodiment, as shown in FIGS. 7 and 11, the ribs 12g are formed on both long sides of the toner frame 12 (upper and lower ends in the lengthwise direction of the right opening 12e). The distance between the flanges 12g is substantially equal to the widthwise length L13 of the connecting surface of the developing frame 13, so that the connecting surface 13h of the developing frame 13 can be provided between the flanges 12g.

In this way, when the frames 12, 13 are connected together by ultrasonic welding, the connecting surface 13h of the developing frame 13 is installed between the flanges of the toner frame 12, and the positioning boss 13i of the developing frame 13 is loaded with toner. In the positioning hole 12c of the frame 12. Then, it is difficult to deform the toner frame due to the vibration generated by the ultrasonic welding, so that the offset between the frames 12, 13 is avoided. In other words, the movement of the toner frame 12 is limited by the development frame 13 because the connecting surface 13h of the developing frame is installed between the flanges 12g on the frame 12 along the upper and lower sides of the toner frame 12, so that both Adding up and down vibrations to the width direction of the toner frame 12 does not cause deformation of the toner frame and displacement between the frames 12,13.

In the embodiment, because all the frames are made of the same material (polystyrene resin), when the frames 12, 13 are welded together, the welding and connection strength between the frames 12, 13 will be significantly enhanced. Since the developing frame 13 is not welded to the cleaning frame 14, it is not necessary to make the cleaning frame 14 of the same material as the toner frame 12 and the developing frame 13 from the viewpoint of improving welding and connection strength.

In an embodiment, the positioning bosses 13 i of the developing frame 13 located on only one long side of the developing frame 13 as described above may also be provided on both long sides of the developing frame 13 . With this arrangement, deformation of the toner frame 12 and developing frame 13 and displacement between the frames 12, 13 can be more effectively prevented during the welding operation.

As shown in FIG. 31, when a plurality of positioning bosses (not shown) of the developing frame and positioning holes 12c (for inserting the positioning bosses) of the toner frame 12 are arranged side by side along the longitudinal direction of the frame, more effective To prevent frame deformation and offset between frames. In this arrangement, the above-mentioned two ribs 12g located in the width direction of the toner frame 12 can be omitted.

(Structure for easy handling of cassette assembly):

When assembling the process cartridge B, the toner conveying member 10b is installed on the toner frame 12, the opening 12e of the toner storage 10a containing the toner is covered with the cover film 28, and the discharge wire 27 is installed. superior. Then, the developing frame 13 is welded to the toner frame. Next, the developing sleeve 10d and the like are loaded into the developing frame 13. As shown in FIG. Then, the toner developing frame C including the assembly of the developing frame 13 and the toner frame 12 is firmly set on the mounting frame, and the components are incorporated into the frame C (see Fig. 33). In the embodiment, as shown in Fig. 32A, a fitting hole 12a is provided at a certain position of the toner frame 12, and the bottom 12b of the frame 12 is made flat. The toner frame 12 is fixed by inserting the mounting piece 36a of the mounting frame 36 into the mounting hole 12a, which facilitates the assembly of components such as the developing sleeve 10d, developing blade 10e and the like, thereby improving the operability of assembly.

The case of assembling the cleaning blade 11a and the like to the cleaning frame 14 is similar to the above case. In the embodiment, as shown in FIG. 32B, the bottom of the cleaning frame 14 is made flat, and a fitting hole 14e is formed on the bottom of the cleaning frame. When the scraper 11a and similar parts are installed on the cleaning frame 14, as long as the assembly boss 37a on the mounting frame 37 is inserted into the assembly hole 14e, the cleaning frame 14 can be easily fixed, so that it is convenient for cleaning the scraper 11a And the assembly of similar parts, thereby improving the operability of assembly.

The automatic assembly will be described below in conjunction with the accompanying drawings.

As shown in FIG. 33, first, for the assembly of the toner and development frame C relative to the assembly frame 36 that moves toward the conveying roller 36b in the direction indicated by the arrow, in step ①, the boss 36a of the assembly frame 36 is inserted into the toner frame 12. hole 12a, install the developing blade in step ②, and fix the developing blade 10e with screws in step ③. Step ④ assembles the developing sleeve 10d, Step ⑤ fixes the developing sleeve, Step ⑥ removes the toner developing frame C and sends the frame C to the next step. After the toner developing frame C is removed, the jig 36 returns to the auxiliary line below and starts step ① again.

As described above, providing (fitting into the mounting frame 36 ) the fitting portion on the toner frame 12 makes it possible to omit the clamping step of clamping the toner frame 12 to simplify the assembly of the toner frame 12 .

Next, a description will be given of the relative movement of the cleaning frame 14 via the transport rollers 37b in the direction indicated by the arrow. As shown in Figure 34, step 1, the boss 37a of the assembly frame 37 is inserted into the assembly hole 14e of the cleaning frame 14, step 2, bonding dipping 11b, step 3, installing the cleaning scraper 11a, step 4, fixing the cleaning blade with screws Scraper 11a, step ⑤, install the photosensitive drum 7, step ⑥, fix the photosensitive drum, step ⑦ remove the assembled cleaning frame 14 and send the frame 14 to the next step. After taking off the cleaning frame 14, the installation frame 37 returns through the auxiliary line below and starts step 1. again.

Similar to the toner developing frame C, providing an assembly portion on the cleaning frame 14 (fitted into the mounting frame 37 ) simplifies assembly of the cleaning frame 14 by omitting a clamping step for clamping the cleaning frame 14 . As shown in FIG. 4 , the cleaning frame 14 is provided with a lock slot 14 o. During automatic assembly, the assembly machine clamps the lock slot to make the cleaning frame move among the stations.

Assembly of the toner frame 12 and the cleaning frame 14 may also be performed by means other than an automatic assembly machine. For example, the frame is manually assembled on a simple assembly line with simple tools, and the work efficiency can be greatly improved if the mounting brackets 36, 37 are used.

The toner developing frame C is connected to the cleaning frame 14 after the components are assembled into the toner developing frame C and the cleaning frame 14 integrally constituted by the assembly of the toner frame 12 and the developing frame 13 . When connected, the frame is often placed on a bench. Before the toner developing frame C is connected to the cleaning frame 14, the photosensitive drum 7 mounted on the cleaning frame 14 and the developing sleeve 10d mounted on the developing frame 13 are both exposed to the outside. Therefore, these components are likely to collide with the stand and be damaged. In particular, the photosensitive drum 7, which is the most important part for forming images in the image forming operation, even a slight damage to the surface of the drum will distort or deteriorate the image to lower the image quality. Therefore, in assembling or the like, when setting the frame with the photosensitive drum 7 or the frame with the developing sleeve 10d on the stand, the operator must take great care not to cause the photosensitive drum 7 or the developing sleeve 10d to come into contact with the stand. frame contact.

In the embodiment, as shown in FIG. 35, the cleaning frame 14 housing the photosensitive drum 7 has a protrusion 14f on the edge of an open end. The photosensitive drum 7 is positioned inward (toward the cleaning frame 14 ) from the line between the ends of the protrusions 14 f. In this structure, as shown in FIGS. 35 and 36, when the cleaning frame 14 is placed on the stage, the protrusion 14f comes into contact with the stage and the photosensitive drum 7 does not come into contact with the stage, thereby preventing the photosensitive drum from being in contact with the stage. 7 surface damage.

Similarly, as shown in Fig. 37, a projection 13j is formed on the side of an open end of the toner developing frame C in which the developing sleeve 10d is mounted. The developing sleeve 10d is positioned inward (toward the developing frame 13) from the line between the ends of the projections 13j. In this structure, when the developing frame 13 integrated with the toner frame 12 is placed on the stand, the protrusion 13j comes into contact with the stand and the developing sleeve 10d does not come into contact with the stand.

In this structure, since the developing sleeve 10d or the photosensitive drum 7 does not come into contact with the stand when the developing frame 13 or the cleaning frame 14 is placed on the stand, the photosensitive drum 7 and the like can be prevented from being damaged unintentionally, Assembling workability is thereby improved. After the components are incorporated into the toner frame 12, the developing frame 13 and the cleaning frame 14 in the above structure, the developing frame 13 is attached to the cleaning frame 14 to assemble the process cartridge B. As shown in FIG. As shown in FIG. 38 , the frames 13 and 14 are connected by a connecting piece 38 . The connection between the frames 13, 14 will be described below.

In Fig. 38, the connector 38 includes a base 38a with a threaded hole 38b, a rod 38c and a spring mounting part 38d, the screw 39 is tightened through the thread 38b, and the parts 38c, 38d are located on both sides of the threaded hole 38b . A lever 38c protrudes downward from the base 38a to prevent a coupling boss (to be described later) of the developing frame 13 from coming off. The spring mounting part 38d is parallel to the rod part 38c, and has a spring 38e protruding downwards farther than the rod part 38c on its free end. Arm portions 13k are located at both longitudinal ends of the developing frame 13, and a connecting boss 13m protrudes laterally from each arm portion 13k. A spring receiving groove is located on the upper surface of each arm portion 13k.

In addition, on the cleaning frame 14, a connection groove 14g for fitting the connection boss 13m is provided. A fastener 14h is located on each groove 14g. The fastener 14h includes a mounting hole 14i into which the rod 38c of the connecting member 38 can be inserted, a nut 14j into which the screw 39 can be screwed, and a through hole 14k into which the spring 38e can be inserted.

As shown in Figures 39A and 39B, in order to connect the toner developing frame C and the cleaning frame 14, the connecting boss 13m of the developing frame 13 is deeply inserted into the corresponding connecting groove 14g on the cleaning frame 14, and then the connecting piece 38 is tightened. Fastened to fastener 14h. That is, each lever member of the connecting member 38 is fitted into the hole 14i, and the spring 38e passes through the through hole 14k and is pressed against the spring receiving groove 13n of the developing frame 13. In this case, the screw 39 is screwed into the threaded hole 38b and tightened on the nut 14j.

The toner developing frame C and the cleaning frame 14 are connected to each other for relative rotation about the connecting boss 13m in the above-mentioned manner, thus completing the assembly of the process cartridge B. When the frames 13, 14 are connected to each other, the contact ring 10f abuts against the peripheral surface of the photosensitive drum 7 so as to define the positions of the photosensitive drum 7 and the developing sleeve 10d. The elastic force of the compression spring 38e biases the developing sleeve 10d toward the photosensitive drum 7 (in an embodiment, the elastic force of the spring 38e is selected to be 2Kg and pushes the developing sleeve 10d with a force of about 1Kg). When the toner developing frame C is attached to the cleaning frame 14, the screw gear 7c at the end of the photosensitive drum 7 meshes with the gear 10g at the end of the developing sleeve 10d.

As shown in the embodiment, in the connecting structure between the toner developing frame C and the cleaning frame 14, since the toner developing frame C can be installed along the direction of the connecting groove 14g, the connecting boss 13m can be outwardly (or inwards) to stretch. Thus, the frames 13 , 14 can be positioned relative to the longitudinal direction (thrust direction), so that a thrust stop can be dispensed with.

Since the connecting piece 38 is inserted from above and fastened, the toner developing frame C can be pressed while the connecting piece 38 is fastened. Generally, after the toner developing frame is connected to the cleaning frame, it is necessary to hook the frame with a tension spring to make the frames close to each other, which requires a space for placing the spring, and the operation of hooking the spring is also very troublesome. In the embodiment of the present application, the tension spring may not be used and the space for placing the tension spring may be saved. In addition, when the screws 39 are loosened to disassemble the frames from each other, the pressure of the compressed spring 38e is released, so that the frames can be easily disassembled due to the absence of the thrust stopper.

(Installation structure of cassette):

The structure of mounting the process cartridge B on the image forming apparatus A will be described below.

As shown in FIGS. 5 and 6 and described above, the left guide rail 17 with the first and second guide rails 17a, 17b and the right guide rail 18 with the first and second guide rails 18a, 18b are formed on the frame 15 of the image forming apparatus. superior. Corresponding to these rails, as shown in Figure 4 (showing the right side of the process cartridge B) and Figure 4o (showing the left side of the process cartridge), the bearing 14a and shaft 21 (guided by the first guide rails 17a, 18a) left/ Protrude from the left and right sides of the cleaning frame 14 of the process cartridge B symmetrically. The protruding ribs 40 guided by the second guide rails 17b, 18b are located left/right symmetrically above the bearing 14a and the shaft 21 .

Pressure surfaces 41 are located on the upper surfaces of both longitudinal ends of the cleaning frame 14, and the pressure surfaces pressed by the pressure members 19 are mounted on the frame 15 of the image forming apparatus. There is also a positioning groove 42 for receiving the connecting piece 20 and for positioning the connecting piece. As shown in FIG. 4 , the auxiliary rib 43 protrudes from the right side of the cleaning frame 14 and is located above the protruding rib 40 . The link 35a is used to open and close the drum shutter 35 . The pivoting movement of the link 35a corresponds to the attachment and detachment movement of the process cartridge B, thereby opening and closing the drum shutter 35 connected to the link. The opening and closing of the drum shutter will be described in detail below.

Attachment and detachment of the process cartridge B to and from the image forming apparatus A will be described below with reference to FIGS. 41 to 44. FIG. Although the left and right sides of the process cartridge B are similarly positioned by the left and right rails 17, 18, only the right rail 18 will be described below for the sake of brevity.

First, as shown in FIG. 41, after opening the opening/closing cover 16 of the image forming apparatus frame 15, the shaft 21 of the process cartridge B is installed on the first guide rail 18a, and the protruding rib 40 is installed on the second guide rail 18b. . Then, as shown in FIG. 42, the process cartridge is inserted into the frame 15 of the apparatus by sliding the shaft 21 and the protruding rib 40 along the guide rails 18a, 18b. Thus, the pressure surface 41 of the process cartridge B is pressed by the pressure member 19 of the frame 15 so that the process cartridge B is inserted into the frame and abuts against the second rail 18b.

Next, as shown in FIG. 43, when the protruding rib 40 exceeds the second rail 18b, the pressure of the pressure member 19 rotates the process cartridge B slightly counterclockwise to support the shaft 21 on the first rail 18a. As shown in FIG. 44, when the process cartridge B is further inserted, the cartridge B is also further rotated counterclockwise, so that the connecting member 20 of the frame 15 is engaged with the positioning groove 42 of the process cartridge B. Then, as shown in FIG. 45, when the operator releases the process cartridge, the shaft 21 of the process cartridge B falls into the bearing 18c by its own weight. At this time, the connecting member 20 is fully engaged with the positioning groove, so that the process cartridge B is loaded into the frame 15 of the image forming apparatus and pressed by the pressing member 19. At this time, the helical gear 7c of the photosensitive drum 7 meshes with the driving gear (see FIG. 6) in the frame 15 to transmit the driving force. When the process cartridge B is installed, the falling motion of the process cartridge B releases the pressure of the process cartridge B from the pressure member 19 . Therefore, the operator who mounts the process cartridge B has a "click" feeling, which makes it easy for the operator to recognize that the process cartridge B is mounted to the mounting position.

The connecting faces 20a, 42a of the connecting member 20 of the equipment frame 15 and the positioning groove 42 of the process cartridge B are parallel to each other. Thus, when the connecting member 20 is mounted on the frame 15, the connecting surface 20a is in a horizontal position. As a result, the design of the connecting piece 20 and its installation on the frame 15 can be simplified, thereby substantially eliminating the occurrence of dimensional errors. Therefore, it becomes easy to correctly mount the process cartridge on the frame 15 of the image forming apparatus.

A roller 19b is mounted on each pressure member 19 so that when the process cartridge B is deflected and the pressure member 19 is pressed against the pressure surface 41, the sliding resistance on the process cartridge pressed by the roller 19b is minimized. In addition, in the embodiment, when the pressure surface 41 of the process cartridge B pressed by the roller 19a has a rib-shaped surface structure, the sliding resistance can be further reduced because the contact area is reduced.

As shown in FIGS. 1 and 4, the upper surface of the process cartridge B, which is formed substantially flat, is substantially parallel to the direction in which the process cartridge B is installed. In this way, the installation space of the process cartridge B in the image forming apparatus frame 15 can be made as small as possible, and some spaces in the process cartridge B (such as the space for the toner storage and the waste toner storage) can be made as small as possible. Take advantage of.

On the other hand, as shown in FIG. 46, when the process cartridge B is detached, the process cartridge B is slightly rotated (indicated by arrow a) and clockwise to disengage the protruding rib 40 from the step 18b1 of the second guide rail 18b, so that The process cartridge can be drawn out and removed as it is. When the process cartridge B is rotated excessively counterclockwise, the auxiliary rib 43 (see FIG. 4) will abut against the shutter template 18d (for the left guide rail 17, the protruding rib 40 abuts against the vibration-limiting guide rail (see FIG. 5). )) to limit the rotation of the process cartridge in the counterclockwise direction. When the process cartridge is installed, the auxiliary rib 43 located on the right side of the process cartridge is inserted between the second guide rail 18b and the shutter template 18d, and the protruding rib 40 located on the left side of the process cartridge is inserted between the second guide rail 17b and the limit guide rail 17d. between. In this way, the access path is restricted when the process cartridge B is installed and removed, so that the process cartridge B can be installed and removed more smoothly.

(open/close structure of drum shutter):

The drum shutter 35 is opened and closed relative to the process cartridge loading and unloading motion. Next, the opening/closing operation of the drum shutter will be described in detail.

As shown in FIG. 4, a drum shutter 35 having an arm portion 35b is rotatably mounted about a shaft 35c, and a link 35a is rotatably mounted on the shaft 35c so as to move together with the arm portion 35b. Then, when the link 35a rotates, the arm portion 35b also rotates to open and close the drum shutter 35 . A link boss 35d protrudes from the arm portion 35b. The drum shutter 35 can be opened and closed by using the drum shutter template 18d to interact with the connecting rod 35a and the connecting rod boss 35d. The opening and closing of the drum shutter when the process cartridge B is loaded into the image forming apparatus A will be described below with reference to FIGS. 41 to 45. FIG.

As shown in FIGS. 41 to 45, the shutter module 18d on the right rail 18 has a first template 18d1 engaged with the link 35a and a second template 18d2 engaged with the link boss 35d. The inclination angle of the first template 18d1 is substantially equal to that of the second guide rail 18b for guiding the protruding rib 40 of the process cartridge B, while the inclination angle of the second template 18d2 is larger than that of the first template 18d1.

As shown in Fig. 41, when the process cartridge B is inserted and pushed, the link 35a is engaged by the first template 18d1 of the shutter template 18d (as shown in Fig. 42) to rotate the link 35a about the shaft 35c. As a result, the arm portion 35b is rotated to open the drum shutter 35; however, at this time, the drum shutter is not fully opened but is only in a so-called half-open state. As shown in FIG. 43, when the cassette B is further pushed in, the rotation of the arm portion 35b disengages the connecting rod 35a from the first template 18d1 and engages the connecting rod boss 35d with the second template 18d2. As shown in FIG. 45, when the process cartridge B is fully loaded, the drum shutter 35 is fully opened so that the recording medium 2 conveyed under the cartridge is not hindered by the drum shutter.

When the process cartridge B is drawn out from the state shown in FIG. 45 to detach the process cartridge B from the image forming apparatus A, the elastic force of the torsion spring 35e locked on the arm portion 35b makes the drum shutter 18d in the reverse order to the above. The drum shutter is closed by being engaged by the link boss 35d and the link 35a in turn.

The above-mentioned drum shutter 35 is used to protect the photosensitive drum 7 . In the embodiment, a laser shutter is provided in the image forming apparatus A in addition to the drum shutter 35 . The laser shutter constitutes a laser light path blocking means to prevent the laser light emitted from the optical system 1 from leaking from the optical unit 1a (of the imaging device) to irradiate the photosensitive drum 7 under the non-operating condition of the device.

(Laser light path blocking device):

The structure of the laser light path blocking device will be described below. As shown in Fig. 47, the optical unit 1a has an opening 1a1 through which laser light can be irradiated on the photosensitive drum 7, and a laser shutter 46 bent from a metal plate can cover the opening 1a1. The laser shutter 46 has a shutter portion 46a including a bent metal plate and a link portion 46b located on the left side of the shutter portion, and both are integrally formed. The laser shutter 46 is rotatably mounted on the frame 15 of the image forming apparatus via a shaft 46c.

In the vicinity of the left guide rail 17 that guides the process cartridge B, an arm portion 47 is rotatably mounted about a shaft 47a. The arm portion 47 has a free end engageable by the link 46b of the laser shutter 46 . The arm portion 47 is positioned against the end of the process cartridge B when the cartridge B is mounted on the frame 15 of the apparatus.

In this structure, when the process cartridge B is inserted guided by the left and right guide rails, an opening/closing member of the cartridge B pushes the arm portion 47 in the direction indicated by the arrow in FIG. Thus, the free end of the arm portion 47 is pushed against the link of the laser shutter 46 to rotate the shutter portion 46b in the direction indicated by the arrow b. Then, the optical unit 1a rotates in the direction indicated by the arrow b. Thus, the opening 1a1 of the optical unit 1a is opened so that the laser light can be irradiated on the photosensitive drum 7. As shown in FIG.

The biasing force of the tension spring provided on the link 46b of the laser shutter 46 always drives the laser shutter 46 toward the closing direction of the opening 1a1. Thus, when the operator detaches the process cartridge B from the image forming apparatus A, since the driving force of the arm portion 47 is removed, the laser shutter 46 automatically closes the opening 1a1 by the elastic force of the spring 47.

Therefore, the laser light from the optical unit 1a cannot be irradiated on the photosensitive drum 7 and the like except when the process cartridge B is loaded into the image forming apparatus to perform an image recording operation. Since the link 46b and the arm 47 for opening and closing the laser shutter 46 are located near the left guide rail 17 and opposite to the right guide rail 18, the space for installing these components is fully occupied. Therefore, the space is effectively used and the size of the device is reduced. In an embodiment, as shown in FIG. 48, the boss 14m abuts against the arm 47 at a distance of about 5-6mm from the free end of the cassette.

(offset of the grip):

As shown in Fig. 48, when the operator loads the process cartridge B on the image forming apparatus A, the boss 14m located at the left (in the longitudinal or axial direction) shoulder of the process cartridge B pushes the arm portion located on the frame of the image forming apparatus 47 (for opening and closing the laser shutter 46). At the same time, the metal shaft 21 (diameter X1 is about 10mm, and the extension X2 is about 5mm) protrudes from the right side of the processing cartridge B and is used as the drum ground to connect with the elastic ground connector (electrical contact) 51 located on the equipment frame. . In addition, the link located on the right side of the cassette B abuts against the shutter template 18d of the frame to open the drum shutter 35 .

Thus, when the cartridge B is installed, to open the laser shutter 46, a pressure is applied longitudinally on the left side of the cartridge B against the biasing force of the spring 47b. On the other hand, the right side of the process cartridge B is subjected to a pressure to deform the elastic connecting member 51 due to contact between the metal shaft 21 and the ground connecting member 51 and a force against the torsion spring 35e for opening the drum shutter 35. Bias force pressure. In the embodiment, the force for opening the drum shutter 35 is the largest among the above-mentioned pressures. Therefore, when the cartridge is inserted, the cartridge is biased by pressure from the longitudinal center C2 of the cartridge.

Therefore, in the embodiment, as shown in FIG. 48, the ribs 12d are positioned so that the longitudinal center C1 of these ribs (constituting the grip portion of the cartridge B) is extended from the longitudinal center C2 of the process cartridge B to the connection where the drum shutter 35 is provided. One side of the rod 35 a and the metal shaft (conductive member) 21 is offset. That is to say, in the embodiment, the longitudinal center C1 of the rib 12d is offset from the center C2 of the longitudinal length L11 (about 300mm) of the process cartridge B by about 10mm (when the process cartridge B is loaded into the image forming apparatus A, the rib 12d The longitudinal center C1 is shifted by about 10 mm from the center of the recording medium conveyance path or from the longitudinal center of the photosensitive drum 7 of the process cartridge B by about 10 mm).

With the above structure, as shown in FIG. 49, when loading the process cartridge B into the image forming apparatus A, the operator grasps the right side of the longitudinal center C2 of the cartridge B, that is, the side where the link 35a of the drum shutter 35 is provided and Insert the cassette into the device. In doing so, the side of the cassette B in which the link 35a is provided in the longitudinal direction receives a force slightly greater than that of the other sides. Due to the bias of force, the pressure to open and close the drum shutter 35 is eliminated, so that the cassette B can be smoothly inserted into the image forming apparatus A without shaking as a whole. In addition, since the rib 12d is parallel to the photosensitive drum 7 disposed along the longitudinal direction of the cartridge B, when the cartridge is inserted into the cartridge by the grasping rib 12d, the longitudinal direction of the cartridge is easy to maintain perpendicular to the insertion direction of the cartridge, so that it is easy to remove the cartridge during insertion. The shaking of the two longitudinal ends.

In addition to forming the grip with the rib 12d shown in Figure 48, the groove 73 on the frame as shown in Figure 50 can also be used or the boss or flange 74 on the frame as shown in Figure 51 can be used to form the grip. grip. That is, the grip portion may be formed of any structure that is convenient for the operator to grip.

Certainly, the position setting of the grip part in the embodiment of the present invention is not limited to the example of being offset to the side of the connecting rod 35 a of the drum shutter 35 and the metal shaft 21 . For example, when the elastic force of the spring 47b of the laser shutter 46 is strong and the pressure against the biasing force of the coil spring 35e is greater than the pressure against the biasing force of the spring 47b and the pressure to deform the connecting member 51, the position of the gripping portion is set to be biased. One side with a boss 14m. In this arrangement, when the process cartridge is loaded into the image forming apparatus, the grip portion should be disposed toward a side where the frame is subjected to greater assembly resistance due to abutting between parts of the image forming apparatus and the frame.

(Description of electrical contacts):

The following describes the electrical connection between the components when the process cartridge B is loaded into the image forming apparatus.

When the process cartridge B is loaded into the image forming apparatus A, each contact point on the process cartridge B is connected with each contact point on the frame 15 of the image forming apparatus, so that the process cartridge B is electrically connected to the image forming apparatus. That is to say, as shown in FIG. 52, a contact point 27a (made of stainless steel in the embodiment) located at the end of the discharge wire 27 as a conductor for detecting the remaining amount of toner is exposed from the lower part of the developing frame 13, and at the same time as a conductor. A developing bias contact 48 (made of stainless steel in the embodiment) for applying a developing bias to the developing sleeve 10d is also exposed. In addition, a charge bias contact 49 made of a conductor (stainless steel in the embodiment) for applying a charge bias to the charge roller 8 is exposed from the lower portion of the cleaning frame 14 . With respect to the photosensitive drum 7, the contact 27a of the discharge wire 27 and the developing bias contact 48 are located on one side, and the charging bias contact 49 is located on the other side. Charge bias contact 49 is integral with contact 26 (FIG. 10).

With respect to these contacts (as shown in FIG. 35 ), with respect to the transfer roller 4, the discharge wire contact 50 connected to the contact 27a of the discharge wire 27 and the developing bias contact 48 connected to the developing bias contact 48 when the process cartridge B is loaded in are connected. A pressure connection plug 50b is provided on one side in the recording medium conveyance direction, and a charge bias connection plug 50c connected to the charge bias contact point 49 is provided on the other side. As shown in FIG. 54, the connection plugs 50b, 50c accommodated in the housing 50d can protrude from the housing but do not slide off the housing. These connection plugs are pushed upward by springs 50f and are electrically connected to wirings on the electric substrate 50e. The seat cover 50d is mounted on the electric substrate 50e via a spring 50f. Among the contacts 48, 49 abutting against the connecting plugs 50b, 50c, the charging bias contact 49 is formed into an arcuate shape having a straight line portion and a bent portion connecting the straight line portions, and the bent portion is located at the shaft hinge of the opening/closing cover 16. 16a side. In this way, after the process cartridge B is loaded, when the opening/closing cover 16 is closed in the direction indicated by arrow C around the hinge 16a, the charging bias contact 49 closest to the hinge 16a and having the smallest radius of rotation can be smoothly and effectively connected to the connecting plug. 50c connection.

The shaft 21 supporting one end of the photosensitive drum 7 is made of metal, and the photosensitive drum 7 needs to be grounded through the metal shaft 21 . For this reason, as shown in FIGS. Thus, the shaft 21 is connected to the ground member 51 when the cartridge is loaded.

Next, referring to FIG. 22, the arrangement of the electrical contacts will be described. As shown in FIG. 22, the contact points 48, 49 are provided on the side of the photosensitive drum 7 on which the helical gear 7c is not mounted, and the metal shaft 21 as a drum grounding member is located on the other side of the photosensitive drum 7. As shown in FIG. In a direction perpendicular to the longitudinal direction of the photosensitive drum 7 , ie, in the recording medium transport direction, the developing bias contact 48 is located on the side of the photosensitive drum facing the developing device 10 , and the charging bias contact 49 is located on the other side. A metal shaft 21 serving as a drum ground protrudes from the frame 14 and is on the rotation center line of the photosensitive drum 7 .

The developing bias contact 48 and the charging bias contact 49 are arranged in a line longitudinally with respect to the photosensitive drum 7 and on both sides of the gear flange (spur gear) 7 d and the photosensitive drum 7 . Meanwhile, the contact points 48, 49 are provided on the inner side of the outer end surface of the longitudinal gear flange 7d of the photosensitive drum 7. As shown in FIG. The above arrangement can reduce the longitudinal dimension of the process cartridge B to reduce the volume of the process cartridge.

As mentioned above, the charging bias contacts 49 are bent outwardly. That is, when the process cartridge is loaded, the straight portion of the contact 49 becomes the leading end and the contact is bent from the straight portion. With this structure, when the process cartridge B is loaded into the image forming apparatus A, even if the contact angle between the charging bias contact 49 and the charging bias connection plug 50c of the image forming apparatus deviates, this deviation will is eliminated so that the charging bias contact 49 and the charging bias connection plug 50c are effectively abutting against each other. Although the charge bias contact 49 is positioned forward when the process cartridge B is loaded into the image forming apparatus A, the contact 49 and the connection plug 50c are not damaged during the process cartridge mounting operation.

In addition, the contact point 27a of the discharge wire 27 for detecting the remaining amount of toner in the toner storage 10a of the developing device 10 on the side of the imaging device and the development bias contact point 48 are located on the same side relative to the photosensitive drum 7 in the longitudinal direction, And the space between the photosensitive drum 7 and the photosensitive drum 7 is larger than that of the developing bias contact 48 on one lateral side of the photosensitive drum 7 (toward the developing device).

When the above-mentioned contact arrangement is used, since the charging bias contact 49 is separated from the metal shaft 21 of the grounding member, there is no risk of floating capacitance, thereby stabilizing the charging voltage and avoiding charging deviation. That is, if the drum ground contact is close to other contacts, a floating capacitance will be generated between the discharge wire and the contact arranged around the drum ground contact and similar other contacts, and the result will be used for developing, charging and toner level detection There is a deviation in the AC voltage. Especially when the charging roller in contact with the photosensitive drum 7 charges the drum 7, since the constant current control is implemented, if the AC voltage fluctuates due to the floating capacitance, the image quality will be deteriorated. On the contrary, if the contact arrangement in the embodiment is used, the floating capacitance will be eliminated, and the AC voltage will be kept stable or normal so as to avoid charging deviation.

In addition, since the developing bias contact 48 and the charging bias contact 49 are separately provided on both sides of the photosensitive drum 7, electrical interference between these contacts is avoided.

In view of the above, in the embodiment, when the process cartridge B is assembled, the metal shaft 21 is attached to the cleaning frame 14 supporting the photosensitive drum 7 in a direction protruding outward from the drum 7 with respect to the axial direction of the drum 7, At the same time, charge bias contacts 49 are mounted on the opposite side of the metal shaft 21 relative to the drum axis. Further, the developing bias contact 48 is attached to the toner developing frame C supporting the developing device 10 . When the cleaning frame 14 and the toner developing frame C are connected to each other, the contact point 48 is in the axial direction of the photosensitive drum 7 . After that, the frames 14 and C are connected to each other so that the process cartridge B is assembled.

(Toner remaining amount detection and cartridge installation detection circuit):

Next, the toner remaining amount detection and process cartridge installation detection will be described. In this apparatus, as described above, the remaining amount of toner in the process cartridge B is detected based on the change in electrostatic capacity between the discharge wire 27 on the cartridge and the developing sleeve 10d. For this purpose, the circuit shown in Fig. 55 is provided in this device.

As shown in Fig. 55, the developing sleeve 10d and the discharge wire 27 constitute an equivalent capacitor. The high-voltage power supply HV applies a rectangular wave AC voltage (Vpp = about 1600V) to the developing sleeve 10d. The high voltage from the high voltage power supply HV has rectangular rising and falling sections and is shaped into a derivative waveform ANT by the electrostatic capacitance between the developing sleeve 10d and the discharge wire 27 and the resistances R1, R2. Diode D1 is a clamping diode with a negative output. The derived waveform ANT is divided by resistors R1, R2 and peak-detected by the first peak-hold circuit composed of operational amplifier OA1, diode D2 and capacitor C1, and converted into a DC signal. Resistor R3 is used to discharge capacitor C1.

The electrostatic capacitance between the developing sleeve 10 d and the discharge wire 27 depends on the amount of toner present between the developing sleeve 10 d and the discharge wire 27 . That is, when the dielectric constant between two conductors increases, the electrostatic capacitance between the two conductors also increases. Therefore, when the amount of toner decreases, the voltage detected by the first peak hold circuit decreases when the amount of toner decreases because the dielectric constant between the conductors decreases and the electrostatic capacitance also decreases.

On the other hand, the output from the high voltage power supply HV is supplied to the developing sleeve 10d and a derivative circuit composed of a reference capacitor C2, a resistor R4, a resistor R5 (volume resistor) and a resistor R6. Diode D3 is a clamping diode with a negative output. The derived waveform detected by resistor R5 is converted into a DC signal by the second peak hold circuit composed of operational amplifier OA2, diode D4, capacitor C3 and discharge resistor R7. Adjust volume resistor R5 so that the output of the second peak hold circuit becomes the required reference voltage (approximately 2.7V in the embodiment).

The comparator CO1 compares the output of the first peak hold circuit (the potential of the capacitor C1 → the value corresponding to the remaining amount of toner) with the output of the second peak hold circuit (the potential of the capacitor C3 → the reference voltage) and outputs a signal representing the toning Dose remaining signal. Thus, when there is a sufficient amount of toner remaining between the developing sleeve 10d and the discharge wire 27, the potential of the capacitor C1 is greater than the potential of the capacitor C3 and the output of the comparator CO1 becomes a high level. When the toner amount between the developing sleeve 10d and the discharge wire 27 decreases, the potential of the capacitor C1 decreases. When the potential of the capacitor C1 is lower than the potential of the capacitor C3, the output of the comparator becomes low level. Therefore, the remaining amount of toner can be detected based on the detection of the output of the comparator CO1.

It is also necessary to detect whether the process cartridge B is mounted on the image forming apparatus A in the embodiment. That is to say, as shown in FIG. 55, when the potential of the capacitor C1 becomes smaller than the reference potential E (approximately 1V in the embodiment), the output of the comparator CO2 becomes low level, which indicates that the process cartridge B is not Attach to imaging device A.

For example, when the power is turned on, the controller controlling the apparatus outputs a rectangular alternating current from the high voltage power supply HV to the developing sleeve 10d. However, if the process cartridge B is not loaded in the image forming apparatus A, since the photosensitive drum 7, the developing sleeve 10d and the discharge wire 27 are not in the circuit of Fig. 55, the control signal is not input to the operational amplifier OA1. At this time, the potential of the capacitor C1 becomes zero. Thus, when there is no toner in the cartridge, the presence/absence of the process cartridge B can be detected by adjusting the reference potential E to a positive voltage with a margin from zero level and making the potential E lower than the potential of the capacitor C1. exist.

The voltage relationship between the remaining toner amount detection level and the cartridge installation detection level is shown in FIG. 56 . In Fig. 56, the detection reference voltage (potential of the capacitor C3) for the presence/absence of the toner remaining amount can set an alarm value indicating that the amount of toner for recording is insufficient. In the embodiment, the volume resistance R5 is adjusted to a certain electrostatic capacitance (about 7.5pF) (in production) based on the condition that about 20 g of toner exists between the developing sleeve 10d and the discharge wire 27. reference voltage. The reference voltage for detecting the presence/absence of the cartridge installation can be obtained by dividing the power supply voltage by the resistor.

In the circuit of Fig. 55, the presence/absence of the cartridge is detected using the comparator CO2. In Fig. 57, commutators IN1, IN2 with appropriate clipping values can be used instead of comparator CO2. In this case, it is necessary to adjust the detection voltage value from the discharge wire 27 through the resistors R1, R2, R4, R5, R6 so that the output of the inverter IN1, IN2 does not go low when there is no toner in the cartridge level.

In addition, as for the detection of presence/absence of the cartridge, as shown in FIG. 58, when the output of the capacitor C1 is sent to the controller through an isolation amplifier BA for A/D conversion, the detection will be more reliable.

(Control section):

Next, the control system of the image forming apparatus A will be briefly described with reference to the functional block diagram shown in FIG.

In FIG. 59, a control section 60 for controlling the entire image forming apparatus includes a CPU of a microcomputer, a ROM storing a control program of the CPU and various data, and a RAM serving as a work area of the CPU and temporarily storing various data.

The control section 60 receives signals from a sensor group 61 including a paper jam sensor and the like. The control section also receives a signal from a remaining toner detecting mechanism 61a in the cartridge which detects the remaining amount of toner based on the electrostatic capacity between the developing sleeve 10d and the discharge wire 27. In addition, the control section also receives image signals from a host computer 62 such as a computer, word processor or the like.

Based on these signals the control section 60 controls various processes such as exposure 63, charging 64 (charging roller 8 and the like), developing 65 (developing sleeve 10d and the like), transfer 66 (transfer roller 4 and the like) , fixing 67 (fixing roller 56 and the like), and recording medium conveyance 68 (registration rollers 3d1, 3d2, output rollers 3f1, 3f2 and the like). The control section also controls the main drive motor 71 through a counter 70 that records the number of pulses that the control section applies to the driver 69 .

In an embodiment, the control portion 60 also receives a signal indicating that the toner detection result is toner-free and activates an alarm 72 (for example, turning on a light or activating a buzzer) indicating replacement of the process cartridge.

(imaging operation):

The image forming operation after the process cartridge B is installed in the image forming apparatus A will be described below.

As shown in FIG. 1, when the recording medium 2 is loaded into the paper feed tray 3a and a sensor (not shown) detects the loading of the recording medium or when the cassette 3h containing the recording medium 2 is loaded and the copy start key is pressed , The pickup roller 3b or 3i starts to rotate, while the paired separation rollers 3c1, 3c2 and paired registration rollers 3d1, 3d2 rotate to send the recording medium 2 to the image forming station. Synchronized with the conveyance of the pair of registration rollers 3d1, 3d2, the photosensitive drum 7 rotates in the direction of the arrow in FIG. Subsequently, laser light corresponding to the image signal from the optical system 1 is irradiated on the photosensitive drum 7 through the exposed portion 9, thereby forming a latent image corresponding to the image on the drum.

Simultaneously with the formation of the latent image, the developing device 10 in the process cartridge B is driven to rotate the toner conveying member 10b to output the toner in the reagent storage 10a to the developing sleeve 10d, and to form a toner layer on the sleeve 10d. . The latent image on the photosensitive drum 7 becomes a visible toner image by applying the same voltage and potential as the charging polarity of the photosensitive drum 7 to the developing sleeve 10d. The recording medium 2 is sent between the photosensitive drum 7 and the transfer roller 4, and a voltage opposite to the polarity of the toner is applied to the transfer roller 4, so that the toner image on the photosensitive drum 7 is transferred onto recording medium 2. After the transfer, the photosensitive drum 7 continues to rotate in the direction of the arrow in FIG. 1, and at the same time, the remaining toner on the photosensitive drum 7 is scraped off by the cleaning blade 11a and collected into the waste toner storage 10c.

In addition, the recording medium 2 with the transferred toner image is sent to a fixing device 5 where the toner image is fixed on the recording medium 2 with heat and pressure. After that, the output rollers 3 e , 3 f 1 , 3 f 2 send the recording medium 2 to the output area 6 . As for the fixing device, in the embodiment, while a so-called thermal fixing type device is used, other types of fixing devices such as a pressure type fixing device may also be used.

(recycling of processing cartridges):

The recycling of the processing cassette will be described below based on the embodiment. Thus, when the toner in the process cartridge is exhausted, the cartridge is discarded. In this way, still usable components such as rollers are also discarded with the process cartridge. Recently, out of consideration for the protection of the earth's environment, various electrical and electronic devices have not been discarded in the old way, and the parts of these devices must be recycled (renewed or reused) to help save resources, energy and reduce dust .

Thus, those long-lived components in the process cartridge according to the embodiment, such as the charging member, developing member or cleaning member, can be used after the toner in the cartridge is used up. Therefore, currently, the toner-depleted process cartridges are collected and the usable parts therein are recycled.

The procedure for handling cassette recycling is described below. The procedure includes the following steps, (1) collection, (2) sorting, (3) disassembly, (4) selection, (5) cleaning, (6) inspection, (7) reassembly. These steps are detailed below.

(1) Collect:

Used process cassettes are sent to collection centers by users and maintenance personnel.

(2) Classification:

The used processing cartridges collected at each collection center are transported to a cartridge recycling factory, and the collected processing cartridges are sorted by type.

(3) Decomposition:

Disassemble the sorted process cassette into large components.

(4) Choose:

This large set of parts is inspected for selection or sorted into usable parts and unusable parts due to wear or end of life.

(5) Cleaning:

Clean only selected qualified parts for recycling as new parts.

(6) Inspection:

After cleaning, it is checked whether the parts are fully functional and can be reused.

(7) Reassembly:

Reassemble a new process cartridge from certified parts.

In recycling, the charging roller 8, the developing sleeve 10d and the like are reassembled to be reused, and the frames 12, 13, 14 are crushed for material utilization. If the frames 12, 13, 14 consist of different materials, when the frames are pressed together, the different materials mix together, which tends to reduce the mechanical properties of the material being reused. Therefore, each frame 12, 13, 14 must be crushed individually or separately. However, since the welded toner frame and the developing frame need to be cut and separated from each other, the recycling procedure becomes troublesome. But, as said in the aforementioned embodiment, the toner frame 12, the developing frame 13 and the cleaning frame 14 all adopt the same material (polystyrene resin), so even if the frames 12, 13, 14 are pressed together Crushed into small particles, its mechanical properties will not be reduced, thus improving the recycling process.

In the embodiment, since the frame material polystyrene resin is a material similar to the components of the toner (both are styrene), even if the toner sticks to the frame due to incomplete cleaning In addition, the mechanical properties of the frame material obtained after crushing will not be reduced as different materials are mixed.

Because the cleaning frame 14 can be separated from the toner developing frame C, it is not necessary to make the cleaning frame with the same material as the toner developing frame, but when using a material similar to the toner component material When manufacturing these frames, it is preferable to make the cleaning frame from the same material as that of the toner developing frame C. However, the cleaning frame 14 must have sufficient strength to support the photosensitive drum 7 and the like. However, as shown in the embodiment, when the cleaning frame 14 is made of polystyrene resin, which is the same material as the toner developing frame C, the mechanical strength of the cleaning frame is smaller than that made of polyphenylene oxide (PPO) or polyphenylene ether. (PPE) for the mechanical strength of cleaning frames. Therefore, as shown in FIG. 60, in the embodiment, the cleaning frame 14 is provided with an upper wall 14n (FIG. 4, 7 and 47-51) to strengthen the side wall 14P.

A partition wall 14q provided on the waste toner container 11c divides the interior of the container into a plurality of chambers, and reinforcing ribs 14r are provided on the sides of the partition wall of each chamber to reinforce the cleaning frame. The partition wall 14q restricts erroneous longitudinal movement of the toner in the waste toner storage 11c and thus prevents waste toner from leaking from the waste toner storage 11c. Strengthening the cleaning frame 14 as described above allows the frame 14 to obtain sufficient mechanical strength when the cleaning frame 14 is made of the same material (polystyrene resin) as the toner developing frame C.

[Other embodiments]

Other embodiments of the aforementioned process cartridges and components of the image forming apparatus will be described below.

(charging unit):

In the foregoing embodiments, the axial movement of the charging roller 8 can be restricted by abutting one end of the roller shaft 8 a against the supporting surface 24 a of the bearing 24 . In another embodiment, as shown in FIGS. 61 and 62, one end of the charging roller shaft 8a may be supported by a bearing 52 having a cylindrical cavity 52a. In this structure, when the charging roller shaft 8a is directed toward the arrow in FIG. 61, one end surface of the charging roller shaft 8a will be supported by the bottom 52b of the cavity 52, thereby positioning the roller. Therefore, this structure can achieve the same effect as the previous embodiment. The bearing 52 is preferably made of a material having good sliding properties against metal, such as polyacetal resin, similar to the bearing 24 in the previous embodiment.

As shown in Fig. 63, a lateral groove 52c may be formed in the bearing 52, and the charging roller shaft 8a is forcibly inserted into the bearing 52 while the groove 52c is elastically deformed. This structure improves the assemblability of the charging roller 8 . When the process cartridge B is installed, if the direction of the groove 52c is downward, even if a small amount of swarf is left in the cylindrical cavity 52a, since these swarf can fall out of the cavity 52a through the groove 52c, the charging roller shaft can be made Rotate stably in cavity 52a.

In the foregoing embodiments, the structure in which one end of the charging roller shaft 8a is supported by the bearing 24 or 52 has been described. The developing sleeve 10d and the like can also be supported by the bearing 24 or 52 .

In the first embodiment, in order to prevent the elastic deformation of the contact point 26 caused when the charging roller shaft 8a moves, the restricting member 14b is provided. In another embodiment shown in FIG. 64, a rib 53 is provided as a restraining member on the cleaning frame 14, and the joint 26 can be fixed to the rib 53 by heat pressing or the like. With this structure, if the charging roller 8 is subjected to the force P indicated by the arrow in FIG. Therefore, in use, the contacts 26 will not be damaged even if a force P is generated due to the cartridge falling off during transportation.

As shown in FIG. 65, a cushioning pad 54 made of rubber or the like is bonded to the side of the rib 53 with a double-sided adhesive tape so that the cushioning pad is placed between the rib 53 and the joint 26. As shown in FIG. With this structure, when the charge roller 8 is subjected to the force P indicated by the arrow, the buffer pad 54 prevents the contact point 26 from being elastically deformed. If the contact end portion is not in parallel contact with the end surface of the rotating roller shaft 8a, the contact of the contact point 26 with the end surface of the roller shaft 8a will cause vibration and/or noise due to eccentricity. However, since the buffer pad 54 is provided in the embodiment to eliminate vibration, noise generation is avoided.

(developing unit):

In the aforementioned first embodiment, as shown in FIG. 15, three ribs 13b, 13c, 13d are provided on the developing frame 13, and the sharp wedge shape of the second rib 13c penetrates into the developing blade 10e. As shown in the example of Fig. 66, the end of the second rib 13c need not be wedge-shaped, but may be formed into a sharp arrow shape, and the pointed end of this rib 13c can abut against the developing blade 10e strongly.

In the first embodiment, as shown in FIG. 18, the bent portion 27b on the discharge wire 27 prevents the discharge wire 27 from floating from the recess 13e of the developing frame 13 when the exposed portion of the discharge wire 27 is impacted. The shape of the bent portion 27b is not limited to that shown in Fig. 18, but it may be a semi-circular shape as shown in Fig. 67A or a trapezoidal shape as shown in Fig. 67B.

In order to prevent the discharge wire 27 from floating, as shown in FIG. 68, an opening 13P provided on the developing frame 13 is used instead of the bent portion 27b. The discharge wire 27 can pass through the opening 13P. With this structure, when the discharge wire 27 is subjected to the external force shown by the arrow in FIG. gaps or gaps.

In addition, instead of the opening 13p (as shown in Fig. 69), a circular cavity 13q having a diameter limiting the passage of the discharge wire 27 is provided on the developing frame 13, and the discharge wire 27 can pass through the cylindrical cavity 13q. With this structure similar to the opening 13P, when the discharge wire 27 is subjected to an external force shown by an arrow in FIG. 69, the discharge wire 27 does not float from the developing frame 13.

In the first embodiment, the positioning of the developing sleeve 10d in its rotational direction was explained. This positioning can also be similar to the positioning of the charging roller 8 shown in Figures 61 to 63 by abutting one end of the developing sleeve shaft against a bearing, which may be cylindrical. When both the developing sleeve 10d and the non-magnetic toner are used, an applicator roller is required to form a toner layer on the developing sleeve 10d. In this structure, the coating roller can be positioned by abutting one end of the coating roller against a bearing having the above-mentioned structure.

(cleaning unit):

In the foregoing embodiments, as shown in Figs. 12, 13A and 13B, the overlapping of the expansion sheet 10i and the toner leakage preventing seal 10h has been explained. 12, 13A and 13B can be considered in terms of the relationship between the cleaning means (cleaning blade 11a, dipping sheet 11b, toner leakage preventing seal 11e) and the photosensitive drum 7. That is, the dipping sheet 11b can overlap the toner leak-proof seals 11e on the outsides of both longitudinal ends of the cleaning blade 11a.

(other):

The process cartridge of the present invention is suitable for forming not only monochromatic images as described above, but also multicolor images (for example, two-color images, three-color images or full-color images) by providing a plurality of developing devices 10 .

As the developing method, ordinary two-component magnetic brush developing method, shower developing method, contact developing method or cloud developing method can be used.

Regarding the charging device, in the first embodiment, when a so-called contact type charging device is used, a wall containing three tungsten wires is closed by a metal cover such as aluminum, and positive and negative ions generated by applying high voltage to the tungsten wires are transferred to the photosensitive drum 7 A common charging device for uniformly charging the surface of the photosensitive drum 7 can be used.

The charging device may be of a blade (charging blade) type, a pad type, a block type, a rod type, or a wire type in addition to the aforementioned roller type.

The cleaning means for removing residual toner on an image carrier such as the photosensitive drum 7 may be constituted by a scraper, a fur brush and/or a magnetic brush.

As for the image carrier as the photoreceptor, organic semiconductor (OPC), amorphous silicon (A-Si), selenium (Se), zinc oxide (ZnO) or cadmium sulfide (CdS) can be used. The shape of the image carrier is not limited to a drum shape, but may be a belt shape.

The process cartridge B comprises an electrophotographic photoreceptor as an image carrier and at least one processing means. The process cartridge can be constituted as an integral unit that can be detachable on an image forming apparatus containing an image carrier and a charging device, or constitute a detachable unit containing an image carrier and a developing device that can be detached on an image forming apparatus. or constitute an integral unit containing an image carrier and a cleaning device that can be disassembled on an imaging device, or constitute an image carrier and two or more processing devices that can be installed on A detachable integral unit as described above on an imaging device.

That is to say, the process cartridge is constituted as an integral unit detachable from an image forming apparatus containing an electrophotographic photoreceptor, and a charging device, a developing device or a cleaning device, or as a unit containing an electrophotographic photoreceptor. A photoreceptor, and at least one of a charging device, a developing device, and a cleaning device are an integral unit detachable from an image forming device, or constituted as an electrophotographic photoreceptor and at least one developing device that can be mounted on an image forming device. An integral unit that is removable from an imaging device.

The image forming apparatus in the foregoing embodiments is a laser copier. However, the present invention is not limited to laser copiers. The invention can also be used in other imaging equipment such as LED copiers, electrophotographic copiers, facsimile systems or word processors.

As mentioned above, since the frames constituting the casing of the processing cartridge in the present invention are all made of the same material, the welding between the frames is firm and reliable.

Since the material constituting the frame is similar to the toner, even if the toner adheres to the crushed frame material when the cartridge is recovered, the mechanical properties of the material will not be deteriorated like when different materials are mixed together. Therefore, it is not necessary to separate the frame when recycling, simplifying the cleaning operation.

Since the charging characteristics of the material constituting the frame are similar to those of the developer, abnormal charging due to the friction of the developer against the frame does not occur during image forming operations, resulting in high quality images.

As described above, according to the present invention, since the mechanisms for opening and closing the drum shutter and the laser shutter for the image carrier are provided on both sides of the cassette frame, the space can be effectively used, thereby downsizing the image forming apparatus.

In addition, since substantially the same load occurs on both sides of the cartridge in the cartridge insertion direction when the cartridge is loaded and unloaded with respect to the image forming apparatus, it is possible to reduce some vibration during loading and unloading of the cartridge, thereby improving mounting accuracy.

From these, it can be seen that the present invention can provide a process cartridge, a method of assembling such a process cartridge, and an image forming apparatus, which can achieve stability in loading and unloading of the process cartridge.

Claims (34)

1, a kind of magazine that is installed in the image device comprises:

An image carrier;

An electric-conductor that is installed in an axial end of described image carrier contacts with the electric contact of described image device, makes described image carrier electrical ground, and

A turned parts is close to laser optical path occluding device in the described image device, when being installed in the described image device, is used for opening laser optical path to the processing magazine,

It is characterized in that described turned parts is contained in described image carrier another axial end portion away from the axial end that above-mentioned electric-conductor is installed.

2, a kind of processing magazine as claimed in claim 1 is characterized in that described turned parts is the boss that forms on the magazine framework handling.

3, a kind of processing magazine as claimed in claim 1 is characterized in that in the time will handling magazine and be contained in the described image device, and described laser optical path occluding device leans against to be handled on the magazine in the zone away from this processing magazine end 5-6 millimeter.

4, a kind of processing magazine as claimed in claim 1 is characterized in that described image carrier has rotating photosensitive drums, described electric-conductor and this photosensitive drums coaxial arrangement.

5, a kind of being installed in has the processing magazine of blocking-up in the image device of the occluding device of the laser optical path that laser beam emitting device sends, and comprising:

A framework;

An image carrier that is contained in the described framework, and

The shutter assembly that can close the opening that forms on the described framework, in order to protecting above-mentioned image carrier,

A side that it is characterized in that described framework is equipped with the mechanism that is used for opening and closing described shutter assembly; The opposite side of described framework is equipped with and drives described occluding device.

6, a kind of processing magazine as claimed in claim 5, it is characterized in that handling magazine electronic photography photoreceptor and charging mechanism as described image carrier integrally are housed, and developing apparatus or the cleaning device used as processing mechanism, they can be removably mounted in the described image device as a unit.

7, a kind of as claim 1 or 5 described processing magazines, it is characterized in that handling magazine integrally be equipped with electronic photography photoreceptor as described image carrier, charging mechanism and as in the middle of the developing apparatus of above-mentioned processing mechanism and the cleaning device at least one, they can be removably mounted in the described image device as a unit.

8, a kind of as claim 1 or 5 described processing magazines, it is characterized in that handling magazine and integrally be equipped with as the electronic photography photoreceptor of above-mentioned image carrier and at least one developing apparatus of using as processing mechanism, they are removably mounted in the described image device as a unit.

9, a kind of as claim 1 or 5 described processing magazines, it is characterized in that handling magazine and comprise that at least one is used for the charging device to described image carrier uniform charging, be used for forming developing apparatus that latent image develops and the cleaning device that is used to remove residue on the described image carrier on the described image carrier.

10, a kind of processing magazine can being installed on wherein so that form the image device of video on recording medium comprises:

Laser beam emitting device;

Be used to block the occluding device of the laser optical path that sends from described laser beam emitting device;

The installing mechanism of processing magazine that can the mounting strap image carrier, be placed in the axial end of this image carrier and be suitable for making this image carrier electrical ground electric-conductor and lean against on the described occluding device opening the turned parts of described light path, and

When this processing magazine is installed, the electric contact that contacts with described electric-conductor,

The butted part that it is characterized in that leaning against the described occluding device on the described turned parts is arranged in and the opposite other end of described electric contact one end is housed.

11, a kind of image device as claimed in claim 10 is characterized in that described occluding device comprises described butted part and the blocking part that is used for blocking described light path.

12, a kind of image device includes:

Laser beam emitting device;

The installing mechanism of handling magazine can be installed; this processing magazine comprises framework and is contained in the interior image carrier of this framework; can close the opening that forms in the described framework to protect the shutter assembly of described image carrier; being used for opening and closing is loaded on the mechanism of the described shutter assembly of described framework one side; and the mechanism that is used for driving the described occluding device that is loaded on described framework opposite side, also have

The conveying mechanism that is used for conveying recording medium.

13, a kind of as claim 10 or 12 described image devices, it is characterized in that this image device is an Xerox.

14, a kind of as claim 10 or 12 described image devices, it is characterized in that this image device is a laser beam printer.

15, a kind of as claim 10 or 12 described image devices, it is characterized in that this image device is a telewriter.

16, a kind of processing magazine that is installed in the image device comprises:

A framework;

An image carrier that is contained in the described framework;

Be contained in the described framework processing mechanism that described image carrier is worked;

An electric-conductor that is installed in the axial end of described image carrier; And

A tripper that is used to be close to described image device is to open the turned parts of laser optical path, and described turned parts is contained on the described framework of described another axial end of image carrier.

17, a kind of processing magazine as claimed in claim 16 is characterized in that described turned parts is away from 5～6 millimeters at the above-mentioned end of described framework.

18, a kind of processing magazine as claimed in claim 16 is characterized in that described turned parts is the boss that is formed on the described framework.

19, a kind of processing magazine as claimed in claim 16 is characterized in that described turned parts is the boss that is formed at described framework upper.

20, a kind of processing magazine as claimed in claim 16 is characterized in that described turned parts is installed in becomes guiding parts handling when magazine is contained in the described image device state.

21, a kind of processing magazine as claimed in claim 16 is characterized in that described electric-conductor is a ground contact, makes the photosensitive drums ground connection as described image carrier.

22, a kind of processing magazine as claimed in claim 16, it is characterized in that this processing magazine integrally is equipped with electronic photography photoreceptor as described image carrier, charging mechanism and as the developing apparatus or the cleaning device of processing mechanism, they are removably mounted in the described image device as a unit.

23, a kind of processing magazine as claimed in claim 16, it is characterized in that handling magazine electronic photography photoreceptor as described image carrier integrally is housed, charging mechanism and as the developing apparatus of processing mechanism and at least one in the cleaning device, they are removably mounted in the described image device as a unit.

24, a kind of processing magazine as claimed in claim 16, it is characterized in that this processing magazine integrally has the electronic photography photoreceptor as described image carrier, and at least one developing apparatus of using as processing mechanism, they are removably mounted in the described image device as a unit.

25, a kind of processing magazine can being installed on wherein so that form the image device of video on recording medium comprises:

The installing mechanism of processing magazine that (a) can the mounting strap framework, be contained in image carrier in the described framework, be contained in the processing mechanism that in the described framework described image carrier worked, be placed in the electric-conductor of the axial end of described image carrier and be close to and open the turned parts that laser optical path is used on the tripper of image device, described turned parts is contained on the described framework of described another axial end of image carrier;

(b) laser beam emitting device is used for the described image carrier of laser radiation at the described processing magazine that is loaded on described installing mechanism, and

(c) tripper that can conversion between blocking state and opening, blocking-up stops the blocking state of described tripper from the laser that described laser beam emitting device sends when opening when blocking state.

The described turned parts that it is characterized in that described processing magazine is close on described tripper, opens described laser optical path.

26, a kind of image device as claimed in claim 25 is characterized in that described tripper converts described blocking state to when the described turned parts of described processing magazine is separated with described tripper.

27, a kind of image device as claimed in claim 25, it is characterized in that described tripper have can conversion between described blocking state and described opening shutter section, then laser is blocked when blocking state, when opening, then described shutter section is return from described blocking state and the butted part that is close to described opening section.

28, a kind of image device as claimed in claim 25 is characterized in that this image device is an Xerox.

29, a kind of image device as claimed in claim 25 is characterized in that this image device is a laser beam printer.

30, a kind of image device as claimed in claim 25 is characterized in that this image device is a telewriter.

31, a kind of assembling can be installed in the method for the processing magazine in the image device, comprises the steps:

With (a) first framework and (b) second framework interconnect and be assembled into the processing magazine, wherein first framework has framework, be contained in the image carrier in this framework, be installed in the electric-conductor of an axial end of described image carrier, and being close to the opening section of the tripper of described image device in order to unlatching laser, described opening section is contained on the described framework at another axial end of described image carrier; Second framework has framework, the developing apparatus that is contained in this framework and is suitable for the latent image that forms on the described image carrier is developed.

32, a kind of method as claimed in claim 31 is characterized in that described first framework also has the charging mechanism that is contained in this framework, to described image carrier charging.

33, a kind of method as claimed in claim 31 is characterized in that described first framework is contained in the cleaning device in this framework in addition, in order to clean described image carrier.

34, a kind of method as claimed in claim 31 is characterized in that described second framework is by the developing frame of the described developing apparatus of supporting and the developer splendid attire framework that comprises the developer of using in the described developing apparatus are formed by connecting.

Images