JP2002328582A - Electrophotographic image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability at loading a process cartridge for storing a large amount of toner, to improve positional accuracy and to accomplish a stable drive. SOLUTION: A projection constituted of an inclined surface 20j, an apex part 20k, an inclined surface 20m and an upper surface 20l is arranged on the process cartridge 15 which is positioned when a guide part 19f descends while swinging, and in the case of pressurizing the projection by a process cartridge pressurizing member 120 interlocking with a control handle, the leading end part 120a of the pressurizing member 120 is pushed into the inclined surface 20j against a spring 122, and the leading end part 120a runs over the apex part 20k, then, the leading end part 120a rushes into a V-shaped groove having the inclined surface 20m and the upper surface 20l by the spring force of the spring 122 so as to press the process cartridge 15, then, the operability is improved by attaining a click feeling, and the positional accuracy and the stable drive can be attained by the spring force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

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

[0003] A process cartridge is a unit in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive drum are integrated into a cartridge, and this cartridge is detachable from the main body of the electrophotographic image forming apparatus. is there. In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive drum are integrally formed into a cartridge so that the cartridge can be attached to and detached from the electrophotographic image forming apparatus main body. Further, at least the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus.

[0004]

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

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

[0006]

However, in recent years,
With the spread of the so-called "cartridge system", users have come to pursue more convenience. At the same time, higher quality, lower cost, and space saving are also required.

Further, there is a demand for a process cartridge having a large toner capacity in order to cope with an increase in the number of copier sheets. When the toner storage amount is increased, the process cartridge becomes heavier, and the operability of attachment and detachment to and from the image forming apparatus main body is reduced. In addition, it is necessary to consider the positioning of the process cartridge when it is mounted on the image forming apparatus main body in view of the weight distribution.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has improved operability, can save space in the entire apparatus, and has a high-quality process cartridge and accurately positions the process cartridge. It is an object of the present invention to provide an electrophotographic image forming apparatus which can be mounted by mounting.

[0009]

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

According to a first aspect of the present invention, there is provided an electrophotographic image forming apparatus which detachably attaches a process cartridge and forms an image on a recording medium, comprising: an electrophotographic photosensitive drum; a process means acting on the electrophotographic photosensitive drum; Mounting means for removably mounting a process cartridge having a pressure receiving surface pressurized by a pressure means of the image forming apparatus main body, and an image forming apparatus of the process cartridge for press-positioning the process cartridge A pressurizing unit that can be moved in conjunction with the mounting operation to the main body, and a conveying unit for conveying the recording medium, wherein the process cartridge mounting operation includes the electrophotographic photosensitive drum and Including a first operation in which the process cartridge rotates about a substantially parallel rotation center, and interlocking with the first operation An electrophotographic image forming apparatus characterized by a second operation in which the pressure means is moved to a position for pressurizing said process cartridge is performed.

A seventh invention according to the present application includes a first operation in which the process cartridge is rotated around a rotation center substantially parallel to the electrophotographic photosensitive drum, as the operation of attaching and detaching the process cartridge. In a process cartridge detachable from the image forming apparatus main body having a process cartridge mounting means for performing a second operation in which a pressurizing means moves to a position for pressurizing the process cartridge in conjunction with the operation 1, A process cartridge comprising: a photosensitive drum; a process unit acting on the electrophotographic photosensitive drum; and a pressure receiving surface pressed by the pressurizing unit.

[0012]

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

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

Process cartridge 15 of the present embodiment
As shown in FIG. 1, a charging roller 12 serving as a charging unit is provided around an electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 11 serving as an image carrier, a developing sleeve 18 and a developing blade 26 serving as developing devices. A toner storage frame 16 storing toner and a cleaning blade 14 as cleaning means are arranged, and are integrally formed as a process cartridge 15 by being covered with a housing. The process cartridge 15 is configured to be detachable from the image forming apparatus main body C.

The process cartridge 15 is mounted on an image forming apparatus main body C as shown in FIG. 2 and used for image formation. In image formation, a sheet S as a recording medium is conveyed by a conveying roller 7 from a sheet cassette 6 mounted on a lower portion of the apparatus, and the photosensitive drum 11 is selectively exposed from an exposing device 8 in synchronization with the sheet conveyance. To form a latent image. Thereafter, a thin layer of the toner stored in the toner storage container 16 is carried on the surface of the developing sleeve 18 by the developing blade 26, and a developing bias is applied to the developing sleeve 18 to supply the toner in accordance with the latent image. The toner image is transferred to a sheet S conveyed by applying a bias voltage to the transfer roller 9, the sheet S is conveyed to a fixing device 10 to fix the image, and is discharged by a discharge roller 1 to a discharge unit 3 in the upper part of the device. I do.

(Frame Structure of Process Cartridge) The structure of the process cartridge will be described with reference to FIGS. 1, 3 to 7. 3 is a diagram of the process cartridge as viewed from one side, FIG. 4 is a diagram of the process cartridge as viewed from the other side, FIGS. 5 and 6 are perspective views of the process cartridge, and FIG. FIG. Further, in the longitudinal direction of the photosensitive drum, the back side of the apparatus main body C or the side to which the drive is transmitted from the apparatus main body C is defined as the drive side, and the opposite side is defined as the non-drive side.

The process cartridge 15 is a cleaning unit integrally supporting the photosensitive drum 11, the charging roller 12, the cleaning blade 14, and the removed toner storage unit 13c which are rotatably supported via drum bearing members 22a and 22b. The developing frame 17 integrally supports the frame 13, the developing sleeve 18, and the developing blade (not shown in FIG. 7), and the toner container 16 storing the toner.
It is composed of two frames. Further, in order to integrally support the three frames, the three frames are fixed by side covers 19 and 20 on both side surfaces of the frames to form an integral process cartridge 15. The detailed configuration of the frame (unit) will be described later.

The non-drive-side side cover 19 is large enough to cover the main cross section of the process cartridge 15, and is disposed at one end in the longitudinal direction of the process cartridge.
The cleaning frame 13 and the toner storage frame 16 are integrally supported from both sides. Hole 1 of this side cover 19
9a is positioned coaxially with the center of the photosensitive drum of the cleaning frame 13. At this time, the positioning of the side cover 19 is performed via the bearing member 22a. Further, a positioning portion 19b provided at a position as far as possible from the photosensitive drum 11 and a positioning portion 13b provided on a side surface of the cleaning frame 13 are fitted to each other to determine a position in the rotation direction. Fixed. Further, the toner storage container 16 has positioning portions 16a, 1 on one end surface thereof.
6b, the positioning portions 16a and 16c are fitted to the positioning portions 19c and 19d disposed on the side cover 19 to determine the position, and are fixed by machine screws 19h and 19i.
The driving side cover 20 also positions the cleaning frame 13 and the developing frame 17 in a similar manner. Further, the bearing member 22 also serves to position the process cartridge to the image forming apparatus. Drive side cover 2
0, the electrodes s3 to s8,
s11 and s12 are provided.

Next, the positioning of the developing frame 17 will be described with reference to FIGS. The developing frame 17 is fitted around the hanging hole 17d provided on the driving side of the developing sleeve 18 with the hanging hole 17d in the cleaning frame 13 so that the center of the developer carrier faces the center of the image carrier. It is swingably supported by the mating pin 17c. In other words, the developing frame 17 including the developer carrier is arranged on the driving side on the cleaning frame so as to be swingable about the hanging hole 17d, and the cleaning frame 13 and the toner storage Since the container 16 is fixed without relatively moving, the developing frame 17 is movable relative to the toner container 16.

Further, on the non-driving side of the developing frame 17, a projecting portion 17e is provided on the central axis in the longitudinal direction of the developing sleeve 18, and the projecting portion 17e is configured to be pressed toward the center of the image carrier. .

The protrusion 17e is provided on the non-drive side side cover 19
Is inserted into a groove 19e (in this embodiment, a linear elongated hole facing the center of the image carrier), and is configured to be movable in the center of the image carrier. An elastic member (not shown) is provided inside the groove 19c so as to press the projection 17e.

The groove 19e also plays a role of positioning for regulating the moving direction of the developing sleeve 18.

Here, when a driving force is applied, the gears provided on the photosensitive drum 11 and the developing sleeve 18 are connected to the suspension holes 1.
It is designed such that forces act in the direction of biting each other around 7d, and no force acts in the direction in which the photosensitive drum 11 and the developing sleeve 18 separate. Further, the developing sleeve 18 is always kept on the photosensitive drum 1 by the elastic member.
It is pressurized toward 1.

Since the developing frame 17 and the toner container 16 are relatively movable, the developing frame 17 and the toner container 16 are connected to each other by a seal member 21 for absorbing the moving range of the two so as to prevent toner leakage. Desirably, the seal member 21 has a shape having a small repulsive force that hinders the movement of the developing device, and has a shape having at least one fold or a bellows shape. The sealing member 21 is provided at the opening 17 a of the developing frame 17.
And an opening 21a communicating with the opening 23c of the plate-like member 23. An edge of one opening 21b is attached to the developing frame 17, and an edge of the other opening 21a is a plate-like member. 23, and the peripheral edge is formed in a bellows shape. The plate-like member 23 is fixed to the edge of the toner supply opening 16c by the sticking portion 23a so that the opening 23c of the plate-like member 23 communicates with the toner supply opening 16c of the toner storage container 16. The sticking portion 23a has a U-shape and one end where the sticking portion 23a is not stuck, and the elastic member 23b is pressed against the toner container 16 at one end. The folded portion of the toner seal (not shown) that seals the toner supply opening 16c is drawn outside through the space between the elastic member 23b and the toner storage container 16.

In the present embodiment, the sealing member 21
Is formed by folding a soft film having a thickness of about 100 μm twice to form a bag shape. In addition, an elastomer may be used to have two folds (not shown) to reduce the repulsion force, and to use a material having excellent flexibility such as a urethane foam member, a low hardness rubber, and silicon instead of the elastomer. May be selected. In this case, the same effect can be obtained even if the bellows shape is omitted. With such a configuration,
Even when the amount of toner increases, the load due to the toner is applied to the side covers 19 and 20 and does not occur on the developing sleeve 18. Therefore, a stable image can be obtained without applying an unnecessary load to the photosensitive drum 11.

Furthermore, by connecting the side surfaces of each frame, each container can be positioned by one part of the side cover, and the containers can be connected with high accuracy.

A stirring member 27 for feeding the stored toner T into the developing frame 17 through the toner supply opening 16c is provided in the toner storage container 16. The toner storage container 16 stores a large amount of toner T, and thus has a large volume.

(Structure and Drive Structure of Photosensitive Drum Unit) Next, the structure of a coupling means which is a drive force transmitting mechanism for transmitting a drive force from the image forming apparatus main body C to the process cartridge B will be described.

In the present embodiment, a drive transmitting unit described in Japanese Patent No. 2875203 is employed as a driving unit of the photosensitive drum 11. FIG. 8 shows the drum flange 3
FIG. 9 is a partially cutaway perspective view of the photosensitive drum 11 to which the reference numeral 0 is attached. FIG. 9 shows a convex shaft 30a (part of the drum flange) and a concave shaft 31 (provided on the apparatus main body C) as a coupling. FIG.

That is, as shown in FIGS. 7, 8 and 9, the drum flange 30 fixed to one end of the photosensitive drum 11 is provided with a coupling convex shaft 30a (cylindrical shape). A convex portion 30b as a twisted protrusion is formed on the tip end surface of the convex shaft 30a. The protrusion 30b
Is parallel to the end surface of the convex shaft 30a perpendicular to the axis. The convex shaft 30a is fitted to the drum bearing 22b and functions as a drum rotation shaft. In the present embodiment, the flange 30, the coupling convex shaft 30a, and the convex portion 3
0b is provided integrally. A helical gear 30c is provided integrally with the flange 30 for transmitting a driving force to the developing sleeve 18 inside the process cartridge.
Accordingly, as shown in FIG. 8, the drum flange 30 is an integrally molded product having the helical gear 30c, the convex shaft 30a, and the convex portion 30b, and is a driving force transmitting component having a function of transmitting driving force.

The shape of the projection 30b is a twisted polygonal prism, more specifically, a substantially equilateral triangular prism twisted in the direction of rotation of the shaft. Further, the concave portion 31a as a twisted hole fitted with the convex portion 30b is a hole twisted in the rotation direction of a shaft having a polygonal cross section. The cross section of the concave portion 31a provided on the end surface of the concave shaft 31 is a substantially equilateral triangle. The recess 31a rotates integrally with a gear (not shown) provided in the apparatus main body C. Therefore, in the configuration of the present embodiment, the process cartridge B is mounted on the apparatus main body C, and the projection 30b and the recess 31a provided on the apparatus main body C are fitted to each other, and the rotational force of the recess 31a is increased. Part 3
When transmitted to 0b, each vertex of the convex portion 30b of the substantially equilateral triangular prism and the inner surface of the concave portion 31a abut equally, so that the axes coincide with each other. Furthermore, the concave shaft 31 is formed by its twisted shape.
Exerts a force in a direction in which the convex portion 30b is attracted, and the convex end surface 30b1 contacts the bottom surface 31a1 of the concave portion 31a. Thus, the axial position and the radial position of the photosensitive drum 11 integrated with the convex portion 30b in the image forming apparatus main body C are stably determined.

Here, the convex shaft 30a and the convex portion 30b
Is provided on the drum flange 30 so as to be coaxial with the axis of the photosensitive drum 11 when the drum flange 30 is attached to one end of the photosensitive drum 11. The drum flange 30 is fitted to the inner periphery of the drum cylinder 11a of the photosensitive drum 11 and attached by "caulking" or "adhesion". Further, the outer periphery of the hollow drum cylinder 11a is covered with a photosensitive layer 11b. Also, on the other end side of the photosensitive drum 11,
A drum flange 32 is fixed. A spur gear 32a is formed integrally with the drum flange 32. A hole (not shown) is provided at the center of the drum flange 32 at the center of the photosensitive drum 11, and the shaft portion 22a1 of the bearing member 22a is fitted to this hole. Bearing member 22a
The shaft portion 22a1 is fitted in the hole 13a of the cleaning frame 13. The bearing member 22a has shaft portions 22a1 and 22a3 on the same center on both sides of the flange 22a2. The shaft portion 22a3 closely fits into the hole portion 19a of the side cover 19 and protrudes outward. Flange 22a2 is machine screw 22
It is fixed to the cleaning frame 13 by c.

The material of the drum flanges 30, 32 is polyacetal.
l), polycarbonate (polycarbonat)
e), polyamide (polyamide) and polybutylene terephthalate (polybutylenenet)
(e.g., elephthalate). However, other materials may be appropriately selected and used.

(Method of attaching / detaching process cartridge to / from apparatus body) Next, attachment / detachment of a process cartridge to / from the apparatus body will be described with reference to FIGS. 1, 3 to 6 and FIGS. 9 to 12. 10 is a view showing a state where the front door 115 of the apparatus main body C is opened, FIG. 11 is a view showing a state where the process cartridge is pushed all the way into the apparatus main body, and FIG. 12 is a state where the process cartridge is set in a predetermined position. It is a figure of a state.

In this embodiment, the mounting of the process cartridge 15 is performed in two stages. That is, in the first stage, the mounting operation is performed in a direction substantially parallel to the photosensitive drum 11, and in the second stage, the operation of swinging about a certain fulcrum on a plane perpendicular to the photosensitive drum 11 is performed. It is.

In the state shown in FIG. 10, the image forming apparatus main body C is provided with rail-shaped guide members 110 and 111 serving as guides when the process cartridge 15 is mounted in the image forming apparatus main body from outside the image forming apparatus. Have been.
The guide member 110 is fixed to the image forming apparatus main body C as an upward groove at the upper left of the space E as shown in FIG. 10, and the guide member 111 is provided as an upward groove at the lower right of the space E. The guide members 110 and 111 are orthogonal to and substantially parallel to the paper surface of FIG.

The process cartridge 15 is a substantially rectangular parallelepiped as shown in FIGS. 5 and 6, and has guide portions 19f, 19g, and 20 serving as guides when the process cartridge 15 is mounted on the image forming apparatus main body C.
f, 20g, and the guide portions 19f, 20f are formed in an arc shape that protrudes from the side surface of the process cartridge 15 and whose tip protrudes downward. Guide part 19g,
20 g has an arc shape protruding downward from the lower surface of the process cartridge 15. Process cartridge 1
5, the lower right guide portions 19g and 20g are arranged on the sides (side covers 19 and 20) parallel to the photosensitive drum 11 at the center of rotation in the first operation for swinging the process cartridge 15. Have been. Guide member 1
9f, 20f (the above-mentioned reference numeral 2)
0 m and 20 l are provided on the diagonal line of the process cartridge 15 through the guide portions 19 g and 20 g. On both side surfaces of the process cartridge 15, convex portions 22a and 22b around the axis of the photosensitive drum 11 are provided. The protruding portions 22a and 22b are
22b.

To insert the process cartridge 15 into the image forming apparatus main body C, first, as shown in FIG. 10, the front door 115 on the front of the image forming apparatus main body C (non-driving side in the axial direction of the photosensitive drum 11) is opened. Pull down and rotate downward to open the front of the apparatus body C. Here, the front door 115 is mounted rotatably with a pivot parallel to the plane of FIG. Then, a space E into which the process cartridge 15 is to be inserted appears as shown in FIG.

Next, as shown in FIG. 11, the guide portions 20f and 19g of the process cartridge 15 are
0 and the guide member 111. Then, straight into the main body of the image forming apparatus (in the depth direction of the paper in FIG. 10).
The process cartridge 15 is inserted into the cartridge. When it is pushed in all the way, the guide portion 20 of the process cartridge 15
f and 20 g slide on the guide members 110 and 111. When further inserted, the guide members 110,
111 and the process cartridge guide portions 19f, 19
According to g, the position of the process cartridge 15 in the left-right direction is determined and inserted. This completes the first mounting operation. Before the end of the first mounting operation, the guide portion 20f
Is supported on a lifter member (not shown) provided on the apparatus main body C.

Next, after the process cartridge is inserted to a predetermined position inside the image forming apparatus main body C, the operation lever 112 is operated. When the operation lever 112 is rotated in the direction of arrow B in FIG.
With a lifter member (not shown) interlocked with the operation lever 112, the guide portions 19g and 20g are used as fulcrums (guide portion 1
9g and 20g abut on the guide member 111 of the image forming apparatus) and swing counterclockwise, that is, so that the process cartridge 15 is lowered to the left in FIG. At this time, the process cartridge 15 swings while the left and right positions of the guide portions 19g and 20g of the process cartridge are determined by the guide member 111 of the image forming apparatus main body C.
The rotation locus of the process cartridge 15 is determined by the convex portions (bearing members) 22a and 22b (22) of the process cartridge 15.
The locus is set by a lifter member (not shown) so that the.

When the process cartridge 15 swings counterclockwise to a predetermined position, the projection 22 of the process cartridge 15 fits into the recess 114a of the positioning member 114 of the image forming apparatus as shown in FIG. The cartridge 15 is securely positioned. Positioning member 1
Reference numeral 14 is fixed to the front and rear side plates of the image forming apparatus main body C so as to sandwich the inserted process cartridge 15, and has a concave portion 114a. Recess 11
4a is a U-shape that is open upward, and the convex portion 22 of the process cartridge 15 enters from the open side. The protruding portion 22 of the process cartridge 15 that has entered is securely fitted into the concave portion 114a of the positioning member. This completes the second mounting operation. Next, at the same time as the end of the second mounting / guiding operation, as described above (see FIG. 9), the operation lever 112
The concave portion 31a moves to the front side of the apparatus in conjunction with, engages with the convex portion 30b of the process cartridge 15, and the photosensitive drum 11 can be rotated. Further, a stirring coupling (not shown) is a stirring coupling of the apparatus main body C (not shown).
And the stirring member 27 can be rotated.

When the paper P is passed through the image forming apparatus main body C, that is, when a clockwise rotating force and a driving force are applied to the photosensitive drum 11, the guide member 111 of the image forming apparatus main body C is used.
Abuts against the guide portions 19g and 20g of the process cartridge to stop rotation.
Is maintained. That is, the process cartridge 15
The center of swing when swings is the stop for paper passing. That is, the position of the process cartridge 15 is determined by the engagement of the coupling and the contact of the guide portion.

When removing the process cartridge 15 from the image forming apparatus main body C, an apparatus reverse to the above-described operation method is performed. That is, the lever 112 is rotated in the direction of arrow C. Then, first, the concave portion 31a is retracted from the convex portion 30b to release the engagement of the coupling, and then the process cartridge 15 swings clockwise by a lifter member (not shown).

When the process cartridge 15 is lifted up to the position shown in FIG. 11, the handle 90 provided on the side of the process cartridge 15 is pulled, and the process cartridge 15 is pulled out.
Is moved to the front and taken out of the image forming apparatus main body C.

Therefore, as the size of the image forming apparatus increases, the weight of the process cartridge increases. Even when the size of the process cartridge increases, when the process cartridge is mounted on the image forming apparatus, the process cartridge is pushed in horizontally to a predetermined position with the lever. Since the process cartridge is reliably positioned only by operating the lever, operability is improved, and positioning accuracy of the process cartridge is improved.

Conversely, when removing the process cartridge from the image forming apparatus, the process cartridge can be removed from the image forming apparatus only by operating the lever and pulling the process cartridge toward the user. Good.

Further, since the guide portion is disposed below the toner storage portion, the guide portion is located near the center of gravity of the process cartridge, so that the swing center is a stable position where lateral displacement is difficult.

In this embodiment, the guide portion is disposed on the side cover. However, the present invention is not limited to this. The guide portion may be extended to the toner storage frame.

(Details of Process Cartridge Pressing Operation)
Next, the process cartridge 1 will be described with reference to FIGS.
The pressurizing operation performed at the same time as the attachment and detachment of 5 will be described in detail. 13 to 15 show surfaces (only an insertion guide and a process cartridge member pressing member are shown) of the process cartridge 15 viewed from the inside of the front cover. FIG. 16 shows the process cartridge, the insertion guide, and the process cartridge pressing member. It is a perspective view.

The process cartridge pressurizing member 120 moves in conjunction with the main body operation lever 112 shown in FIGS.
Around the center. The tip 120a has a spherical diameter S
R has a bullet shape of about 1 to 5 mm, and is fitted to the tip of the support member 120b so as to be able to enter and exit freely. A compression coil spring 12 is provided between the support member 120b and the tip 120a.
Due to the contraction of the support member 2, the support member 120 b can be received to exert an urging force in the distal direction. The support member 120b has a substantially L-shape, and has a longitudinal portion 120b1.
Holds the compression coil spring 122 and the tip 120a described above. A support hole 120b3 is provided in the short portion 120b2.
And is fixedly supported on a rotatable shaft 121 supported by a main body frame (not shown). Axis 12
The operation lever 112 shown in FIG.
When the user operates the operation lever 112, the process cartridge 15 moves up and down and the process cartridge pressing member 1
20 also rotates around the shaft 121.

Then, the process cartridge pressing member 12
Details until 0 reaches a predetermined position (a state in which pressure is applied to the process cartridge 15) will be described in detail. In the state shown in FIG. 13, the operation lever 112 is at the initial position, and the process cartridge pressing member 120 is also at the initial position, that is, when viewed from the front of the apparatus, the front end is substantially at the upper right with respect to the rotation fulcrum (axis 121). Facing the direction. In this state, the compression coil spring 122 is in an extended state. At this time, the process cartridge 15 is at a position where the process cartridge 15 is pushed to the far side of the space E as shown in FIG.

When the user turns the operation lever 112 in the direction of arrow B in FIG. 11, the process cartridge 15 starts to swing. The swing operation of the cartridge 15 is completed. Subsequent to the completion of the swing operation, the operation lever 112 and the pressing member 120 are linked. Operation lever 1
When 12 starts interlocking with the pressing member 120, the state of FIG. 14 is reached. As shown in the drawing, in this state, the process cartridge pressing member 120 has not yet reached a predetermined position. When the operation lever 112 is further rotated, the front end portion 120a abuts on the slope 20j of the projection disposed on the upper surface of the process cartridge 15. When the operation lever 112 is further rotated, the front end portion 120a of the process cartridge pressing member 120 tries to climb over the top portion 20k of the projection having the slope 20j. At this time, the compression coil spring 122 deflects the coil spring, and the slope 20
The urging force of the protrusion having j on the vertex 20k is increased. When the apex 20k of the protrusion is exceeded, the compression coil spring 122 extends again, and the process cartridge pressing member 12
The leading end 120a of the “0” contacts the surface of the V-groove formed by the upper surface 20l (ell) of the process cartridge 15 and the other slope 20m. At this time, the compression coil spring 122 is bent by a predetermined amount, and applies a predetermined pressing force described later to the process cartridge 15. As described above, when the distal end portion 120a of the process cartridge pressing member 120 climbs over the apex portion 20k of the protrusion while rotating the operation lever 112, the user feels some resistance and informs the user of the completion of the mounting of the process cartridge. Can be. The height h of the projection is set to be larger than the spherical radius SR of the tip end portion 120a of the process cartridge pressing member 120. This is to ensure that the tip 120a is in contact with the projection 20m in addition to the projection. If the tip 120a is the upper surface 2
This is because, if it is in contact with only 0l (ell), the reaction force of the urging force F generated by the process cartridge pressurizing member 120 acts in the tangential direction of the turning radius, and may deviate from a predetermined position. . Further, in the state shown in FIG. 14, the angle α between the tangent to the turning radius m1 of the process cartridge pressing member 120 and the slope 20j, the process cartridge pressing member 1
The relationship between the urging force W1 by the urging spring when the 20 comes into contact with the slope 20j and the force (direction is tangential) F acting on the interlocking process cartridge pressing member 120 when rotating the operation lever 112 is as follows: (Μ + TANα) * W1 (μ: coefficient of dynamic friction between the slope 20j and the process cartridge pressurizing member 120). As can be seen from this equation, as α increases, the force F increases to infinity, and it is better to make α as small as possible. However, if it is too small, the leading end 12
The contact distance of 0a becomes longer, and it becomes difficult to give the user a so-called "click" feeling of wearing.

Further, if the process cartridge pressurizing member 120 is retracted in conjunction with the operation lever 112 as described above, it is not necessary to perform a complicated operation when the process cartridge 15 swings, and the space saving of the apparatus can be achieved. It also leads to miniaturization.

Here, assuming that the inner diameter of the coil of the compression coil spring 122 is about 4 to 5 mm, considering the holding portion, the tip 120a has a radius of about 4 mm of the sphere, and the angle β formed by the slope 20m and the slope 20l (ell). = 120 °, the height h of the protrusion is about 4 mm is appropriate. Next, the operating force of the operating lever 112 of the user is changed to the force H in the normal operation.
1. The tip 120a of the pressing member 120 is located at the top of the projection 2
The force H2 when exceeding 0k is H1 = 0.8kgf,
When H2 is about 1.4 kgf, the user feels more comfortable to wear. The length m1 of the operation lever 112 is 120 mm, and the length m1 of the process cartridge pressing member is 60 mm. The force F0 generated when trying to get over can be expressed as: F0 = (H2-H1) * m1 / m2 = (1.4-0.8) * 120/60 = 1.2 kgf. Applying this to the equation, the dynamic friction coefficient μ =
If 0.25 and α = 30 °, F = (0.25 + tan30 °) * W1 = 1.2 kgf W1 = 1.45 kgf. Further, as will be described in detail later, the pressing force W2 when the process cartridge pressing member 120 is at a predetermined position.
Is suitable for W2 = 2.4 kgf, and h =
From 4 mm, an appropriate spring constant of the compression coil spring 122 is determined.

By performing the above-described configuration and setting, the user can be intuitively notified of the mounting of the process cartridge, and problems such as erroneous insertion of the process cartridge can be prevented. The numerical values set so far are typical numerical values, and are not limited to these. For example, the length of the operation lever 112 is about 50 to 80 mm in consideration of a common sense length that can be held by hand, and the length m2 of the process cartridge pressing member 120 is a lever ratio m2 / (the length of the operation lever m1. ), It should be longer than m2. The lower the dynamic friction coefficient μ, the better, and at least one of the protrusion and the tip of the process cartridge pressing member should use a material having good slidability, for example, polyacetal or polyamide. Here, since the projection is a large member that is a part of the frame, polyacetal is used as the process cartridge pressing member from the viewpoint of cost.

As can be seen from FIG. 5, the process cartridge is a substantially rectangular parallelepiped, and the rotation fulcrum is disposed near one corner of a rectangle with respect to a plane orthogonal to the photosensitive drum. In addition, the pressure receiving surface is disposed near a corner that is diagonal to the pivot point. This is because the force generated by the process cartridge pressurizing member in the swinging operation of the process cartridge works efficiently.

Next, in (optimization of the pressure applied to the process cartridge), the appropriate value of the pressure W to be generated when the process cartridge pressurizing member is at a predetermined position (the state of FIGS. 15 and 16) will be described. State. The process cartridge pressurizing member 120 presses the front side and the back side of the apparatus, and the back side of the apparatus will be described first. As described above, the positioning of the photosensitive drum 11 (= positioning of the process cartridge) on the back side is performed around the center of the coupling (X1) as shown in FIG. The rotation direction is regulated by the center of the pivot (X2). Here, if the external force applied to the process cartridge 15 increases, the load applied to the coupling unit increases, and various adverse effects may occur (for example, the exposure position is shifted and the image is blurred). To prevent this, it is necessary to minimize the reaction force R ₁ generated in the coupling center X1. The direction of the force R ₂ generated by the rocking fulcrum X2 in order to swing fulcrum not rise float reliably must be downward. Force F generated by process cartridge pressurizing member 120 satisfying the above conditions
Find x.

[0058] unknown force R _1x, approximation of the tangential force of a circle centering on the Y component R _2Y (X1 of R _1Y and R ₂ is Y-component is the X component of the R _1, also X2 is rotated X for regulation
Since the direction is free), it can be calculated from the balance of the forces in the X and Y directions and the balance of the moment.

The external force acting on the process cartridge
Is the weight F1 of the process cartridge and the load of the transfer roller.
Capacitance to detect pressure F2 and remaining toner sequentially
The electrodes s3, s4, s5, s6 for measuring the amount (FIG. 5)
Pressing force F3, F of the electrode pin of the device body C in contact with
4, F5, F6 and automatic opening of the toner seal
Is detected, and the presence or absence of a process cartridge is detected.
Touches electrodes s7 and s8 (see FIG. 5) for detection
Force F7, F8 of the electrode pin of the device body C for
In addition, when the paper P enters the transfer nip,
Force F9 depending on the strength, open the drum shutter when mounted
Reaction force F10 generated on the receiving surface of
The electrode s11 for applying a charging bias to the
Contact the electrode 12 for applying a developing bias to the lead 18.
The pressing forces F11 and F12 of the electrode pins of the device body C
You. Also, for driving the photosensitive drum 11 described above,
Driving the coupling (30) and the toner stirring member 27
T1, T for rotating the coupling 24 for rotation
2, the position of the action point of Fn (n = 1 to 12, x)
Xn (n = 1 to 12, x), Rn (n = 1,
Assuming that the position vector of 2) is Yn (n = 1, 2),
The three equilibrium equations described in (F)_xn) (N = 1 to 12) + R _1x= 0 (F_Yn) (N = 1 to 12) + R_1Y+ R_2Y= 0 (Fn * Xn) (n = 1 to 12, x) + {(Rn * Y
n) (n = 1, 2) + ΣTi (i = 1, 2) = 0 holds. From this equation, the magnitude of each vector F1 = 2
kgf (half of the total weight of the process cartridge), F2 =
0.6 kgf (half of the total pressure on the transfer roller), F3 to F8
= 0.3 kgf, F9 = 2 kgf (assuming maximum: basis weight 2)
00g / mm2 paper half strength), T1 = 6kgfcm,
Assume T2 = 2kgfcm, T3 = 1kgfcm
You. Further, the process cartridge pressurizing member 120
The direction of the force Fx is Almost fixed in configuration
And ask only for its size. Force R1 is minimized
| Fx | = 2.4 kgf
You.

As described above, by applying the force Fx, it is possible to prevent the occurrence of a concerned problem without applying a large load to the coupling. In the present embodiment, only an example is shown, and the case of external force is considered, but the resultant force in the case where any other external force occurs is calculated,
You just need to apply some force to negate it. In addition, particularly effective cases are effective when a large number of external forces act or a large external force is generated as in the present embodiment.

Next, in the case of the front side of the apparatus main body, the applied external forces are only the own weight F ₁ , the transfer roller pressure F ₂ , and the transfer sheet stiffness F ₉ . Also in this case, it is sufficient to apply a force to cancel the resultant force, but as described above, the drum shaft is
Since it is received in the letter-shaped groove, there is no problem if the downward force is surely superior. Therefore, if the same force is applied to the rear side, parts can be shared, and the cost can be reduced.

[0062]

As described above, according to the invention of the present application, the size of the apparatus can be reduced with a simpler configuration, and the user feels a feeling of mounting when mounting the process cartridge to the apparatus main body. Can be.

Further, according to the invention of the present application, by applying an appropriate pressing force to the process cartridge, stable driving of the electrophotographic photosensitive drum can be realized, and problems such as an increase in torque and image blurring can be prevented. Can be.

[Brief description of the drawings]

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

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

FIG. 3 is a side view as viewed from one side of the process cartridge according to the embodiment of the present invention.

FIG. 4 is a side view of the process cartridge according to the embodiment of the present invention as viewed from another side.

FIG. 5 is a perspective view of a process cartridge according to the embodiment of the present invention.

FIG. 6 is a perspective view of a process cartridge according to the embodiment of the present invention.

FIG. 7 is an exploded perspective view schematically illustrating a frame structure of a process cartridge according to the embodiment of the present invention.

FIG. 8 is a partially cutaway perspective view of the photosensitive drum according to the embodiment of the present invention.

FIG. 9 is a perspective view illustrating a relationship between photosensitive drum driving in the embodiment of the present invention.

FIG. 10 is a front view of the apparatus main body according to the embodiment of the present invention with a front door opened.

FIG. 11 is a front view of a state in which the process cartridge according to the embodiment of the present invention has been pushed all the way into the apparatus main body.

FIG. 12 is a front view showing a state where the process cartridge according to the embodiment of the present invention is housed in a predetermined position.

FIG. 13 is a front view showing a part of the state in which the process cartridge is viewed from the inside of the front cover.

FIG. 14 is a front view showing a part of the state where the process cartridge is viewed from the inside of the front cover.

FIG. 15 is a front view showing a part of the state in which the process cartridge is viewed from the inside of the front cover.

FIG. 16 is a perspective view showing a process cartridge, an insertion guide, and a process cartridge pressing member.

FIG. 17 is a diagram illustrating an external force acting on a process cartridge.

[Explanation of symbols]

C: Image forming apparatus main body E: Space portion h: Height of protrusion P: Paper S: Sheet s1 to s6, s7, s8, s11, s12: Electrode T: Toner 1: Discharge roller 3: Discharge unit 6: Sheet Cassette 7: Conveyance roller 8: Exposure device 9: Transfer roller 10: Fixing device 11: Photoconductor drum 11a: Drum cylinder 11
b photosensitive layer 12 charging roller 13 cleaning frame 13a hole 13b positioning part 13c removed toner storage part 14 cleaning blade 15 process cartridge 16 toner storage container 16a, 16b positioning part
16c: toner supply opening 17: developing frame 17a: opening 17c: pin 17
d: Suspension hole 17e: Projection 18: Developing sleeve 19: Non-drive side side cover 19a: Hole 19b ...
Positioning portion 19c Positioning portion 19d Positioning portion 19e Groove 19f Guide portion 19g Guide portion
19h, 19i: Small screw 20: Drive side cover 20f: Guide part 20g
... Guide part 20j ... Slope 20k ... Apex part 20l ...
Upper surface 20m Slope 21 Seal member 21a Opening 21b Opening 22a, 22b Drum bearing member (convex) 22a1
Shaft 22a2 ... Flange 22a3 ... Shaft 22c ...
Small screw 23: plate-like member 23a: sticking part 23b: elastic member
23c: Opening 24: Coupling (to drive the stirring member) 26: Developing blade 27: Stirring member 30: Drum flange 30a: Convex shaft 30b: Convex portion
30b1 ... convex part end face 30c ... helical gear 31 ... concave shaft 31a ... concave part 31a1 ... bottom surface of concave part 32 ... drum flange 32a ... flat tooth gear 90 ... handle 110, 111 ... guide member 112 ... operation lever 114 ... positioning member 114a ... recess 115 ... front door 120 ... process cartridge pressure member 120a ... tip part 120b ... support member 120b1 ... longitudinal part 12
0b2 ... Short section 120b3 ... Support hole 121 ... Shaft 122 ... Compression coil spring

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H035 CA07 CB04 CD01 CD05 CD07 CD11 CD14 CG03 2H071 BA05 BA13 BA16 BA29 CA02 CA05 DA15 DA26

Claims (10)

[Claims] 1. An electrophotographic image forming apparatus which detachably attaches a process cartridge and forms an image on a recording medium, comprising: an electrophotographic photosensitive drum; a process means acting on the electrophotographic photosensitive drum; Mounting means for removably mounting a process cartridge having a pressure receiving surface pressurized by pressure means, and interlocking with mounting operation of the process cartridge to the image forming apparatus main body for press-positioning the process cartridge And a transport unit for transporting the recording medium, and as a mounting operation of the process cartridge, a rotation center substantially parallel to the electrophotographic photosensitive drum is provided. A first operation of rotating the process cartridge around the center, wherein the pressurizing means operates in conjunction with the first operation; Electrophotographic image forming apparatus characterized by a second operation of moving Seth cartridge into position for pressurizing is performed. 2. The electronic device according to claim 1, wherein in the operation process of the second operation, the vicinity of the tip of the pressurizing unit gets over a step formed on a pressurized receiving surface of the process cartridge. Photographic image forming device. 3. The electrophotographic image forming apparatus according to claim 2, wherein said step portion is provided on a pressure receiving surface of said pressurizing means. 4. The pressure receiving surface is formed in the shape of a V-groove, and the V-groove is substantially opposed to the direction of pressurization by the pressurizing means, and is two edges of the V-groove. The electrophotographic image forming apparatus according to claim 3, wherein one of the protrusions is a part of the step. 5. The image forming apparatus main body, wherein the electrophotographic photosensitive drum has a driven transmission member at an axial end thereof, and the position of the process cartridge is determined by the engagement of the driven transmission member. 2. The electrophotographic image forming apparatus according to claim 1, further comprising: a drive transmission member supported by the pressing member, wherein the pressing force of the pressing unit acts in a direction to cancel a resultant force of an external force acting on the process cartridge. 6. The process cartridge is a substantially rectangular parallelepiped, and the center of rotation in the first operation is disposed near a first side of the rectangular parallelepiped substantially parallel to the electrophotographic photosensitive drum. The operation point of the pressing member is arranged near a second side portion on a diagonal line of the first side portion, and is characterized by the above-mentioned. Electrophotographic image forming apparatus. 7. The attaching / detaching operation of the process cartridge includes a first operation of rotating the process cartridge about a rotation center substantially parallel to the electrophotographic photosensitive drum, and interlocking with the first operation. A process cartridge which is detachable from an image forming apparatus main body having a process cartridge mounting means for performing a second operation in which a pressurizing means moves to a position for pressurizing the process cartridge, comprising: an electrophotographic photosensitive drum; A process cartridge comprising: a process unit that acts on a photographic photosensitive drum; and a pressure receiving surface that is pressurized by the pressurizing unit. 8. A part of the pressure receiving surface forms a step, and in the operation process of the second operation, the tip of the pressing member gets over the step of the receiving surface. A process cartridge according to claim 7. 9. The pressure receiving surface is formed in a V-groove shape, and the V-groove is substantially opposed to the direction of pressurization by the pressurizing means, and is two edges of the V-groove. The process cartridge according to claim 8, wherein one of the protrusions is a part of the step. 10. The process cartridge is a substantially rectangular parallelepiped, and has first and second sides on both sides of a substantially diagonal line on a plane perpendicular to the electrophotographic photosensitive drum. The center of rotation in the operation is disposed near a first side portion of the rectangular body substantially parallel to the electrophotographic photosensitive drum, and the pressure receiving surface is a diagonal line of the first side portion. 10. The process cartridge according to claim 7, wherein the process cartridge is disposed near the second side of the process cartridge. 10.