JP2002328563A - Process cartridge, electrophotographic image forming device and electrophotographic photoreceptor drum unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the positional accuracy of a transfer means. SOLUTION: The twist direction of the projection part 22 of a drum flange 21 fixed at the end part of a photoreceptor drum 11 is made to be the same as that of a transfer roller driving gear 24. In this case, the projection part 22 is a triangular pole twisted in an axial direction, the projection part 22 is drawn into the twisted recessed part of a driving shaft(not shown in figure) of the device main body by thrust (in a direction shown by an arrow A) arising at rotating. The gear 24 is a helical gear. Since thrust by the tooth load of the transfer roller gear 25 attached to the transfer roller 9 works in a direction shown by an arrow C, the transfer roller 9 comes into a thrust check 29, then, the axial position of the roller 9 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive drum unit, a process cartridge, and an electrophotographic image forming apparatus to which the process cartridge can be attached and detached.

Here, an electrophotographic image forming apparatus forms an image on a recording medium by using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.) , An electrophotographic facsimile machine, and an electrophotographic word processor.

As a process cartridge, a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive drum are integrally formed into a cartridge, and this cartridge is made detachable from an electrophotographic image forming apparatus main body. . In addition, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachably mountable to the main body of the electrophotographic image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member 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 A process cartridge is composed of a cleaning unit in which a charging unit, a cleaning unit and a photosensitive drum are integrated, a developing unit and a developing unit in which toner supplied to the developing unit is integrated. The cleaning unit and the developing unit are joined together by a joining member to form a process cartridge.

Conventionally, in an electrophotographic image forming apparatus for forming an image on a recording medium using an electrophotographic image forming process, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, A process cartridge system in which this cartridge can be attached to and detached from the image forming apparatus main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a serviceman.
Operability was significantly improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

As disclosed in Japanese Patent Application Laid-Open No. 11-95639, there is an example in which a twisted convex portion is fitted into a concave portion of an image forming apparatus main body to obtain a good image.

[0007]

SUMMARY OF THE INVENTION The present invention is a further development of the above-mentioned technology, in which the drive is smoothly transmitted from the image forming apparatus main body to the photosensitive drum unit, from the photosensitive drum unit to the developing means and the transfer means, and Electrophotographic photosensitive drum unit, process cartridge, and electrophotographic apparatus in which a good image is obtained by reducing rotation unevenness and vibration of developing means and transfer means, and the transfer means is moved to the reference side to improve the positional accuracy in the drum axis direction. It is an object to provide an image forming apparatus.

[0008]

Means for Solving the Problems The main aspects of the present invention will be described with the same reference numerals as in the claims.

According to a first aspect of the present invention, there is provided an electrophotographic photosensitive drum unit used in an electrophotographic image forming apparatus main body, wherein a cylinder having a photosensitive member provided on a peripheral surface thereof, and a shaft of the cylinder provided at one end of the cylinder. A flange having a convex portion twisted in a direction, and a first helical gear twisted in a direction opposite to the twisting direction of the convex portion on the end side having the convex portion, on the opposite side of the flange and the cylinder. An electrophotographic photosensitive drum unit, characterized in that the end portion has a second helical gear having the same torsion direction as that of the convex portion.

According to a seventh aspect of the present invention, there is provided a process cartridge detachably mountable to the main body of an electrophotographic image forming apparatus, comprising: (a) a cylinder having a photosensitive member provided on a peripheral surface thereof; A flange having a twisted convex portion provided toward the outside in the axial direction; a first helical gear provided on an end portion having the convex portion and twisted in a direction opposite to the twist of the convex portion; and the flange of the cylinder. An electrophotographic photosensitive drum having a second helical gear provided at the end opposite to the side provided with the same and having the same twisting direction and twisting direction as the convex portion; and (b) forming the electrophotographic photosensitive drum. And a developing roller for developing the formed electrostatic latent image.

According to an eighth aspect of the present invention, there is provided an electrophotographic image forming apparatus for detachably attaching a process cartridge to form an image on a recording medium, comprising: (a) a cylinder having a photosensitive member provided on a peripheral surface thereof; A flange having a convex portion twisted in the axial direction of the cylinder on one end side, a first helical gear provided on the end side having the convex portion and twisted in a direction opposite to the twisting direction of the convex portion, A second helical gear provided at the end opposite to the side on which the flange is provided and having the same torsion direction and the same torsion direction of the protrusion, and an electrophotographic photosensitive drum formed on the electrophotographic photosensitive drum. Mounting means for removably mounting a process cartridge having a developing roller for developing the electrostatic latent image, and (b) the image forming apparatus comprising: When attached to the body, a drive shaft having a recess twisted axially engaging said protrusion, (c)
A developing roller gear that engages with the first gear; (d) a transfer roller gear that engages with the second gear; and (e) the concave part is convex when the concave part is engaged with the convex part and rotates. A motor for rotating the drive shaft in a direction in which the unit is drawn in the axial direction; and (f) a conveying unit for conveying the recording medium;
An electrophotographic image forming apparatus comprising:

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Description of Process Cartridge and Apparatus Main Body) FIG. 1 is a main cross-sectional view of a process cartridge according to the present invention, and FIG. 2 is a main cross-sectional view of an 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.

The 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, and a developing roller 18 and a developing blade 31 serving as a developing device. A toner storage frame 16 storing the toner T 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 detachably mountable to 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, the photosensitive drum 11 is rotated in the direction of the arrow in the figure, and the photosensitive drum 11 is uniformly charged by the charging roller 12. Next, a sheet S as a recording medium is conveyed by a conveying roller 7 from a sheet cassette 6 mounted at a lower portion of the apparatus, and in synchronization with the sheet conveyance, the photosensitive drum 11 is selectively exposed from an exposing device 8 to latent image. Form an image. Thereafter, a thin layer of the toner stored in the toner storage container 16 is carried on the surface of the developing roller 18 by the developing blade 31, and a developing bias is applied to the developing roller 18 to supply the toner according to 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) On the other hand, the cleaning frame 13
Constitutes the removed toner reservoir 13a and the charging roller 12
The photosensitive drum 11 is rotatably supported to form a cleaning unit.

The developing unit 17 supporting the developing roller 18 and the developing blade 31 and the cleaning unit are connected with the cleaning unit 13 and the developing unit 17 by a connecting pin 20, and the developing unit 17 having the connecting pin 20 side as an end. A compression coil spring (not shown) is contracted between the root of the arm 19 and the cleaning frame 13, and the photosensitive drum 11 and the developing roller 1 are rotated by the urging force of the moment about the coupling pin 20.
8 is pressed.

The cleaning frame 13 and the toner container 1
Numerals 6 are rigidly connected at both ends in the longitudinal direction orthogonal to the plane of FIG. 1 by one side cover (not shown).

A bag-shaped flexible sheet 32 communicates between the opening 16a of the toner container 16 and the opening 17a of the developing frame 17, and the space between the openings 16a, 17a is sealed from the outside.

As shown in FIG. 3, the photosensitive drum 11 and the developing roller 18 are rotatably rotated so that the drum gear 23 of the drum flange 21 fixed to the end of the photosensitive drum 11 and the developing roller gear fixed to the shaft of the developing roller 18 are provided. Since the gears 26 mesh with each other, a load torque is generated based on a load for rotating the developing roller 18 and a bearing load of the photosensitive drum 11 pressed against the developing roller 18.

(Photosensitive Drum Unit) The configuration of the photosensitive drum unit 27 will be described with reference to FIG.
The photosensitive drum unit 27 has flanges at both ends of the photosensitive drum 11 as shown in FIG. One is a drum flange 21 which receives drive from the image forming apparatus main body C and transmits the drive to the developing roller 18. The drum flange 21 has a convex portion 22 driven by the image forming apparatus main body C, and has a shape in which a triangular prism of a substantially equilateral triangle is twisted. It is twisted in the direction in which the thrust force drawn in the direction A (main body drive input side) acts.

A motor (not shown) and a drive shaft (not shown) driven by the motor are provided on the apparatus main body side. A triangular prism hole into which the triangular prism fits loosely is provided. When the process cartridge 15 is mounted on the apparatus main body C, the drive shaft advances in the axial direction to a certain position, and the concave portion is fitted with the convex portion 22. When the drive shaft rotates, the convex portion 22 is pulled into the concave portion by the action of the twisted triangular prism, hits the bottom of the concave portion at the tip of the convex portion 22, and the longitudinal position of the photosensitive drum 11 is determined.

The photosensitive drum unit 27 has a drum flange 21 and a gear 25 fitted at both ends of a hollow cylindrical drum, and is fixed by caulking or bonding.

(Removal of Process Cartridge from Image Forming Apparatus Main Body) Referring to FIG. 2, an opening through which the process cartridge 15 can enter and exit is provided on the front surface of the image forming and mounting main body C. From the opening in the longitudinal direction parallel to
It is inserted into. The apparatus main body C has a guide rail 33 for guiding a lower right guide portion 15a of the process cartridge 15, and a guide portion 1 at the upper left of the process cartridge 15.
A guide rail 34 for guiding 5b is provided.
The guide portion 15b is provided only on the back side (the side in the back surface direction of FIG. 1), and the guide rail 34 does not exist on the back side. When the process cartridge 15 is inserted into the apparatus main body C, the guide portions 15a and 15b
When the process cartridge 15 is pushed into the apparatus main body by the guide 34, an upper left guide section 1 is provided to a lift 35 provided on the apparatus main body C and operated to move up and down.
5b is supported. Then, when the user lowers the lift 35 with an operation lever (not shown), the process cartridge 15 is lowered on the left side around the contact portion between the guide portion 15 a and the guide rail 33, and the process cartridge 15 is positioned on the axis of the photosensitive drum 11. The positioning boss (not shown) provided at 15 is fitted and positioned in a positioning groove (not shown) of the apparatus main body C, and the photosensitive drum 11 and the transfer roller 9 are pressed against each other.

When removing the process cartridge 15 from the apparatus main body C, the user operates the operation lever (not shown) to lift the guide portion 15b with the lift 35, and pulls the process cartridge 15 from the apparatus main body C to the near side.

The rotation direction of the photosensitive drum 11 is shown in FIG.
In the direction B shown in FIG.

Next, the flange 21 on the same side as the projection 22
Drum gear 23 that transmits a driving force via a developing roller gear 26 fixed to an end of the developing roller 18m.
Is a helical gear having a twist angle direction opposite to the twist direction of the convex portion 22 twisted in the axial direction of the triangular prism.

Next, the gear 2 integral with the flange opposite to the drum flange 21 in the longitudinal direction of the photosensitive drum 11
4 will be described.

On the side opposite to the drum flange 21 which receives a driving force from the image forming apparatus main body C, a transfer roller 9 of a transfer means for transferring an image formed on the photosensitive drum to a sheet S of a recording medium is driven. A gear 25 is coaxially fixed to the transfer roller 9. The gear 24 is a helical gear having a torsion angle in the same direction as the torsion direction of the protrusion 22 of the triangular prism receiving the driving force of the image forming apparatus main body C. The transfer roller gear 25 and the gear 24 mesh. Further, the drum gear 23 and the developing roller gear 26 are engaged.

Here, the twist direction of the projection 22 is left and the twist angle is 30 °. The axial length of the projection 22 is about 4 mm
It is.

The drum gear 23, which is the first helical gear, has 49 teeth and has a reference pitch circle diameter of 30.58 modules 0.6 a torsion angle of 16 degrees Twist direction: right The developing roller gear 26 has 32 teeth and has a reference pitch circle diameter of 19.97 modules 0 .6 Twist angle 16 degrees Twist direction: left.

The transfer roller drive gear 24, which is the second helical gear, has a number of teeth of 42, a standard pitch circle diameter of 30.91, a module 0.7, a twist angle of 18 degrees, and a twist direction: left. 16.93 Module 0.7 Twist angle 18 degrees Twist direction: right.

Next, the operation of the photosensitive drum unit 27 and the transfer roller 9 when the process cartridge is driven will be described.

When a driving force is input in the direction B of FIG. 4 from the image forming apparatus main body C to the twisted convex portion 22 of the triangular prism, the photosensitive drum unit 27 is drawn in the direction A by the thrust force due to the twist of the convex portion 22. .

At this time, the transfer roller gear 25 is moved by the thrust force due to the twist angle of the
In the same manner as described above, a thrust force is generated in the direction C to move.

Here, the thrust force of the projection 22 of the triangular prism has a much larger twist angle and a smaller diameter, so that the reaction force D of the thrust force of the transfer roller 9 to move in the C direction is equal to the direction of the photosensitive drum unit in the A direction. Smaller than the thrust force acting on Therefore, the photosensitive drum unit 27 moves in the direction of arrow A, and the transfer roller 9 also moves in the direction of arrow C (the same direction as arrow A).
The thrust stopper 29 is positioned at the end of the movement.
The developing roller 18 is urged in the direction of arrow E, and a thrust due to the tooth load of the drum gear 23 and the developing roller gear 26 is generated in the direction of arrow A, and urges the thrust in the projection 22.

[0036]

According to the above-described structure, according to the present invention, the drive is smoothly transmitted from the image forming apparatus main body to the photosensitive drum unit, from the photosensitive drum unit to the developing roller and the transfer roller, and the photosensitive drum, the developing roller, A good image was obtained by reducing the rotation unevenness and vibration of the transfer roller, and the transfer means was moved to the reference side to improve the positional accuracy in the axial direction of the photosensitive drum.

[Brief description of the drawings]

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

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

FIG. 3 is a development view of a drive system relating to the photosensitive drum according to the embodiment of the present invention.

FIG. 4 is an external perspective view of a photosensitive drum unit according to the embodiment of the present invention.

[Explanation of symbols]

C: Image forming apparatus main body S: Sheet T: Toner 2: Discharge roller 3: Discharge unit 6: Sheet cassette 7: Convey roller 8: Exposure device 9: Transfer roller 10: Fixing device 11: Photoconductor drum 12: Charging roller DESCRIPTION OF SYMBOLS 13 ... Cleaning frame 14 ... Cleaning blade 15 ... Process cartridge 15a, 15b ... Guide part 16 ... Toner storage container 16a ... Opening 17 ... Developing frame 17a ... Opening 18 ... Developing roller 19 ... Arm 20 ... Connecting pin 21 ... Drum flange Reference Signs List 22 ... Convex part 23 ... Drum gear 24 ... Transfer roller drive gear 25 ... Transfer roller gear 26 ... Developing roller gear 27 ... Photosensitive drum unit 28 ... Transfer roller butting part 29 ... Thrust stop 31 ... Developing blade 33, 34 ... Guide rail 35 ... Lift

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yo Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuo Chatani 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Daisuke Abe 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H035 CA07 CB04 CD07 CD13 CD14 CG03 2H071 AA03 AA06 BA04 BA13 BA16 BA19 BA20 BA27 CA02 CA05 CA07 DA08 DA09 DA15 DA27 3J009 DA02 EA05 EA12 EA21 EA44 FA18

Claims (8)

[Claims] 1. An electrophotographic photosensitive drum unit used in an electrophotographic image forming apparatus main body, comprising: a cylinder provided with a photosensitive member on a peripheral surface; and a convex portion twisted in an axial direction of the cylinder on one end side of the cylinder. A flange having a first helical gear twisted in a direction opposite to a twisting direction of the convex portion on an end portion side having the convex portion, and an opposite end portion of the flange and the cylinder having the convex portion. An electrophotographic photosensitive drum unit having a second helical gear having the same twist direction as the twist direction. 2. The apparatus of claim 1, wherein the convex portion includes a main body gear for receiving a driving force transmitted from a motor of the main body of the image forming apparatus, and a main body concave portion including a twisted surface provided coaxially with the main body gear. And a torsion convex portion that fits with the main body of the image forming apparatus main body, which is driven by a motor of the image forming apparatus main body and rotates, and at this time, the torsion direction of the convex part transmits the drive to the convex part at the time of driving. 2. The electrophotographic photosensitive drum unit according to claim 1, wherein the photosensitive drum unit is twisted in a direction to be drawn toward the concave side. 3. The twisted convex part is a triangular prism, the twist direction is about 4 mm on the left and twisted by about 30 °, and the twist angle of the first helical gear on the convex part side is about 18 °, The number of teeth is 49, the pitch circle diameter is about 31 mm, the torsion angle of the second helical gear at the end opposite to the triangular prism is about 16 degrees, the number of teeth is 42, and the pitch circle diameter is about 31 mm. 3. The electrophotographic photosensitive drum unit according to 1 or 2. 4. The apparatus according to claim 1, wherein the first helical gear transmits drive to a developing roller when the first helical gear is mounted on the image forming apparatus main body, and the second helical gear transmits drive to a transfer roller. 3. The electrophotographic photosensitive drum unit according to any one of 3. 5. The gear specification is selected so that a thrust force generated in the convex portion (driven coupling) is larger than a thrust force generated in the second helical gear. 5. The electrophotographic photosensitive drum unit according to any one of 1 to 4. 6. An electrophotographic image forming apparatus, wherein an electrophotographic photosensitive drum and a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum are integrally formed into a cartridge. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided in a process cartridge detachable from the apparatus main body.
6. The electrophotographic photosensitive drum unit according to any one of items 1 to 5, 7. A process cartridge detachably mountable to an electrophotographic image forming apparatus main body, wherein: (a) a cylinder having a photosensitive member provided on a peripheral surface thereof; and a cylinder provided on one end side of the cylinder toward an axially outer side of the cylinder. A flange having a twisted convex portion, a first helical gear provided on an end portion side having the convex portion and twisted in a direction opposite to the twist of the convex portion, and a side of the cylinder on which the flange is provided. An electrophotographic photosensitive drum having a second helical gear provided at the opposite end and having the same twisting direction and twisting direction as the convex portion; and (b) an electrostatic latent image formed on the electrophotographic photosensitive drum. And a developing roller for developing the toner cartridge. 8. An electrophotographic image forming apparatus which detachably attaches a process cartridge and forms an image on a recording medium,
(A) a cylinder having a photoreceptor provided on a peripheral surface thereof; a flange having a convex portion twisted in an axial direction of the cylinder at one end of the cylinder; and a convex portion provided at an end having the convex portion. A first helical gear twisted in a direction opposite to the twist direction of the first helical gear; and a second helical gear provided at an end of the cylinder opposite to the side on which the flange is provided and having the same torsion direction and the same torsion direction of the convex portion. Mounting means for detachably mounting a process cartridge having an electrophotographic photosensitive drum having: a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum; and (b) When the process cartridge is mounted on the image forming apparatus main body,
A drive shaft having a concave portion twisted in the axial direction engaging with the convex portion, (c) a developing roller gear engaging with the first gear, and (d) a transfer roller gear engaging with the second gear. (E) a motor for rotating the drive shaft in a direction in which the concave portion pulls the convex portion in the axial direction when the concave portion engages with the convex portion and rotates, and (f) transports the recording medium. An electrophotographic image forming apparatus, comprising: