Information
-
Patent Grant
-
6463234
-
Patent Number
6,463,234
-
Date Filed
Wednesday, January 3, 200123 years ago
-
Date Issued
Tuesday, October 8, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Fitzpatrick, Cella, Harper & Scinto
-
CPC
-
US Classifications
Field of Search
US
- 399 25
- 399 111
- 399 113
- 399 116
- 399 119
- 399 123
- 399 167
- 399 358
- 399 359
- 399 360
-
International Classifications
- G03G2118
- G03G2116
- G03G1500
-
Abstract
A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes a first frame; a second frame rotatablely coupled with the first frame; an electrophotographic photosensitive drum provided in the first frame; a developing member, provided in the second frame, for developing a latent image formed on the photosensitive drum with a developer; a cleaning member, provided in the first frame, for removing the developer remaining on the drum; a removed developer feeding member, provided in the first frame, for transporting the developer removed by the cleaning member; a drum driving force receiving member, provided in the first frame, for receiving, from the main assembly, a driving force for rotating the drum when the process cartridge is mounted to the main assembly; a development driving force receiving member, provided in the second frame, for receiving, from the main assembly, a driving force for rotating the developing member when the process cartridge is mounted to the main assembly of the apparatus; a driving force transmitting member, provided in the second frame, for transmitting, to the removed developer feeding member, the driving force received from the main assembly by the development driving force to rotate the removed developer feeding member.
Description
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a process cartridge, and an electrophotographlc image forming apparatus in which a process cartridge is removably installable, and which form an image on recording medium.
Here, an electrophotographic image forming apparatus is an apparatus that forms an image on a recording medium with the use of an electrophotographic image forming method. As an example of an electrophotographic image forming apparatus, an electrophotographic copying machine, an electrophotographic printer (for example, laser beam printer, LED printer, and the like), a facsimile apparatus, a word processor, and the like can be included.
A process cartridge is cartridge that is removably installable in the main assembly of an image forming apparatus, and in which a single or plural processing means and an electrophotographic photosensitive drum, are integrally placed. More specifically, a process cartridge is: a process cartridge that removably installable in the main assembly of an image forming apparatus, and in which a charging means, either a developing means or a cleaning means, and an electrophotographic photosensitive member, are integrally placed; a cartridge that is removably installable in the main assembly of an image forming apparatus, and in which at least one of the processing means among a charging means, a developing means, and a cleaning means, and an electrophotographic photosensitive drum, are integrally placed; or a cartridge that is removably installable in the main assembly of an image forming apparatus, and in which at least a developing means among the aforementioned processing means, and an electrophotographic photosensitive member, are integrally placed.
Conventionally, an electrophotographic image forming apparatus that employs an electrophotographic-image-forming process employs a process-cartridge system, according to which an electrophotographic photosensitive member, and a single or a plurality of the aforementioned processing means, which act upon an electrophotographic photosensitive member, are integrally placed in a cartridge removably installable in the main assembly of an image forming apparatus. According to this process-cartridge system, an image forming apparatus can be maintained by the users themselves, without relying on service personnel, remarkably improving operational efficiency. Thus, a process-cartridge system is widely used in the field of an image forming apparatus.
Referring to
FIGS. 16 and 17
, the conventional technologies regarding the aforementioned process cartridge will be described.
A conventional process cartridge
200
comprises a cleaning unit
201
, a development unit
202
, and a developer containing unit
203
. The cleaning unit
201
holds a photosensitive drum
204
, a charge roller
205
, a cleaning blade
206
, a removed developer conveying member
207
, and the like. The development unit
203
and developer containing unit
203
are fixed to each other, and jointly hold a development roller
209
, a development blade
210
, a developer conveying member
211
, a stirring member
212
, and the like.
The photosensitive drum
204
is rotated by the driving force transmitted thereto from a drum driving force inputting portion, which is provided on the main assembly side of an image forming apparatus, to a driving gear
213
positioned in such a manner that the axial line of the driving gear
213
aligns with the axial line of the photosensitive drum
4
. On the other hand, the development roller
209
rotates as it receives the driving force from a driving gear
213
, which receives the driving force from a driving gear
214
. Further, a driving force is transmitted to the stirring member
212
in the developer containing unit
203
, by the developer stirring member driving gear
216
that receives a driving force from the driving gear
214
by way of idler gears
215
a
and
215
b
. The developer conveying member
211
in the development unit
202
rotates as the driving force is transmitted thereto by a developer conveying member driving gear
218
to which driving force is transmitted from the developer stirring member driving gear
216
by way of an idler gear
217
. The removed developer conveying member
207
rotates in the counterclockwise direction as the driving force is put into a removed developer conveying member driving gear
220
by way of an idler gear
219
.
There has been a tendency to increase the developer capacity of a process cartridge in order to increases the cartridge-exchange interval, that is, the service life, of a conventional process cartridge such as the one described. As a result, the amount of the removed toner has increased, making it necessary to increase the capacity of the removed developer storing portion of a process cartridge.
With the increase in the amount of the removed developer, the load applied to the removed developer conveying member is bound to increase. On the other hand, in order to reduce the overall size of an image forming apparatus, the process cartridge size must be reduced.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a process cartridge capable of efficiently storing the removed developer in its removed developer storage portion, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a compact process cartridge, the size of which is realized by efficiently storing the removed developer in its removed developer storage portion, in spite of the increase in the amount of the removed developer, resulting from an increase in the service life of a process cartridge, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which the increase in the amount of the load placed upon a removed developer conveying member for conveying the removed developer, does not affect the rotation of the photosensitive drum, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge which is removably installable in the main assembly of an electrophotographic image forming apparatus, and which comprises: a first frame portion; a second frame portion pivotally attached to the first frame portion; an electrophotographic photosensitive drum, which is placed in the first frame portion; a developing member, which is placed in the second frame portion to develop an electrostatic latent image formed on the photosensitive drum, with the use of developer; a cleaning member, which is placed in the first frame portion to remove the developer remaining on the photosensitive drum; a removed developer conveying member, which is placed in the first frame portion to convey the developer removed by the cleaning member; a drum driving force transmitting member, which is placed in the first frame portion to receive the force for rotationally driving the photosensitive drum, from the main assembly of an image forming apparatus, when the process cartridge is in the apparatus main assembly; a developing member driving force transmitting member, which is placed in the second frame portion to receive the force for rotationally driving the developing member, from the apparatus main assembly, when the process cartridge is in the apparatus main assembly; and a driving force transmitting member, which is placed in the second frame portion to transmit to the removed developer conveying member, the force received by the developing member driving force transmitting member from the apparatus main assembly, in order to rotate the removed developer conveying member, and also to provide an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a drawing for showing the general structure of the electrophotographic image forming apparatus in the first embodiment.
FIG. 2
is a drawing for showing the general structure of the process cartridge in the first embodiment of the present invention.
FIG. 3
is a drawing for showing the driving force transmission mechanism in the process cartridge.
FIG. 4
is an external view of the process cartridge.
FIG. 5
is a drawing for showing the procedure for installing the process cartridge into the apparatus main assembly.
FIG. 6
is a drawing for showing the process cartridge in the second embodiment of the present invention.
FIG. 7
is a drawing for showing the general structure of the electrophotographic image forming apparatus in the third embodiment of the present invention.
FIG. 8
is a schematic sectional view of the process cartridge in the third embodiment of the present invention.
FIG. 9
is a perspective view of the process cartridge in the partially disassembled state.
FIG. 10
is a perspective view of the process cartridge as seen from above, with the walls of the removed developer storing portion and driving force transmitting mechanism partially removed.
FIG. 11
is a drawing for showing how the first frame portion and second frame portion are joined.
FIG. 12
is a drawing for showing the drum driving force transmitting member on the process cartridge side, and the drum driving force transmitting member on the main assembly side of an image forming apparatus.
FIG. 13
is a drawing for showing the connecting member of the driving force transmitting mechanism of the development unit.
FIG. 14
is a drawing for showing the driving force transmitting mechanism of the process cartridge.
FIG. 15
is a drawing for showing the reaction of the driving force transmitting mechanism when the first frame portion pivots.
FIG. 16
is a drawing for showing a conventional process cartridge
FIG. 17
is a drawing for showing the conventional process cartridge.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
First, the process cartridge and electrophotographic image forming apparatus in this embodiment will be described with reference to the appended drawings.
FIG. 1
is a drawing for showing the general structure of the electrophotographic image forming apparatus in this embodiment, and
FIG. 2
is a drawing for showing the structure of the process cartridge in this embodiment.
FIG. 3
is a drawing for showing the driving force transmitting mechanism in this embodiment, and
FIG. 4
is an external view of the process cartridge.
FIG. 5
is a drawing for showing the procedure for installing the process cartridge into the main assembly of the image forming apparatus.
In the following description of the present invention, the “widthwise direction” of the process cartridge is the direction in which the process cartridge is installed into, or removed from, the apparatus main assembly, whereas the “longitudinal direction” of the process cartridge means is the direction perpendicular (roughly perpendicular) to the direction in which the process cartridge is installed into, or removed from, the apparatus main assembly. The “top surface” of the process cartridge is the surface of the process cartridge that faces upward when the process cartridge is in the apparatus main assembly, whereas the “bottom surface” of the process cartridge is the surface of the process cartridge that faces downward when the process cartridge is in the apparatus main assembly.
(Electrophotographic Image Forming Apparatus)
The image forming apparatus
101
illustrated in.
FIG. 1
is a laser beam printer which employs an electrophotographic image forming method. First, the structure of the conveying means for conveying a sheet of recording medium P (recording paper, OHP sheet, and the like) will be described. Plural sheets of recording medium P are placed in layers in a cassette
102
. The leading edge portion of the top sheet of the layers of recording media P is kept in contact with the peripheral surface of a sheet feeding roller
105
by a sheet feeding plate
104
which is under the pressure generated by a pair of sheet feeding springs
103
. The cassette
102
can be pulled out of the apparatus main assembly in the rightward direction in
FIG. 1
, so that the users can place plural sheets of recording medium P in the cassette
102
. As the cassette
102
is pulled out from the apparatus main assembly, a pair of shafts
103
a
slide upward, being guided by a pair of grooves (unillustrated) in the side walls of the cassette
102
a
. As a result, the sheet feeding plate
104
descends to the bottom of the cassette
102
to allow recording medium P to be smoothly loaded into the cassette
102
.
A feeding roller
105
is fixed to a shaft
105
a
. The shaft
105
a
is provided with a clutch and a solenoid switch (unillustrated), which are attached to one of the longitudinal ends of the shaft
105
a
, in order to control the rotational driving of the feeding roller
105
. On the leading edge side of the recording medium P with respect to the feeding roller
105
, in terms of the direction in which the recording medium P is conveyed, a separating claw
106
is located. Further, on the leading edge side of the recording medium P with respect to the separating claw
106
, a cassette entrance guide
107
is positioned close to the separating claw
106
, being enabled to be pivotally moved by the pressure from a spring (unillustrated). Further, the base portion
108
of the apparatus main assembly is provided with a pair of guide portions
109
, extending in parallel to the lateral walls of the cassette
102
to guide the recording medium P to a registration roller
113
.
As a solenoid switch (unillustrated) is turned on by a sheet feeding start signal, a driving force is transmitted to the shaft
105
a
through the clutch. As a result, the feeding roller
105
is rotated to guide the recording medium P to the cassette entrance guide
107
. Then, only the top recording medium P is sent out of the cassette
102
because of the coefficient of friction. Then, the rotation of the feeding roller
105
causes the leading edge of the recording medium P to reach the nip portion of the registration roller
113
, from which the recording medium P is released forward to be conveyed to the interface between a photosensitive drum
6
and a transfer roller
12
by the registration roller
113
, in synchronism with the leading edge of a developer image on the photosensitive drum
6
, which will be described later.
Thereafter, the developer image, which has been formed on the photosensitive drum
6
through an image formation process, which will be described later, is transferred onto the recording medium P by a transfer roller
12
that is kept pressed upon the photosensitive drum
6
by a predetermined amount of pressure.
After the transfer of the developer image onto the recording medium P, the recording medium P is guided into a fixing means
116
by a fixing-means-entrance guide
114
. As the recording medium P passes through the nip between a fixing roller
117
and a pressure roller
118
, the developer image is fixed to the surface of the recording medium P. Then, the recording medium P is discharged from the apparatus main assembly by a discharge roller
120
, and accumulated in a delivery tray
122
provided next to a sheet delivery opening
121
.
Next, the structure of a scanner unit
124
, which is a laser based optical system of the image forming station, will be described. A beam L of laser light is moved by the rotational driving of a polygon mirror
126
, in a manner to scan the peripheral surface of the photosensitive drum
6
in a direction parallel to the generating line of the photosensitive drum
6
. During this scanning movement of the laser beam L, the laser of the scanning unit
124
is turned on and off to change the potential level of the illuminated points on the photosensitive drum
6
to a predetermined level. As a result, an electrostatic latent image is formed on the photosensitive drum
6
.
(Process Cartridge)
Next, referring to
FIG. 2
, the structure of a cartridge
1
will be described. The cartridge
1
in this embodiment comprises: the photosensitive drum
6
; a charge roller for charging the photosensitive drum
6
for image formation (primary charge); a development station
2
for developing an electrostatic latent image formed on the photosensitive drum
6
; a developer container
3
for holding developer; a cleaning station
4
for recovering the developer remaining on the peripheral surface of the photosensitive drum
6
after image transfer; a removed developer storing portion for storing the removed and recovered developer; and the like. The development station
2
and developer container
3
are constructed as two integral parts of a development unit.
The image forming method employed by the image forming apparatus in this embodiment is one of the commonly known electrophotographic processes. The structure of the cartridge
1
in this embodiment will be described with reference to this electrophotographic process. The charge roller
7
is positioned adjacent to the peripheral surface of the photosensitive drum
6
, on the upstream side of the exposing point, that is, the point at which the peripheral surface of the photosensitive drum
6
is exposed to the laser beam L. The charge roller
7
is a semiconductive elastic member, which is kept pressed upon the photosensitive drum
6
by a predetermined amount of pressure, and follows the rotation of the. photosensitive drum
6
. As bias is applied to the charge roller
7
, the peripheral surface of the photosensitive drum
6
is uniformly charged. Then, as described above. the peripheral surface of the photosensitive drum
6
is scanned by the laser beam L, and as a result, an electrophotographic latent image is formed on the peripheral surface of the photosensitive drum
6
.
Meanwhile, a certain amount of the developer t in the developer container, which is the same in polarity as the primary charge, is picked up by a stirring member
8
, and is sent into the development station
2
, through a developer supplying opening
9
, by the stirring member
8
. Then, the developer t is adhered to the peripheral surface of a development roller
10
, and is formed into a thin layer of the developer t by a development blade
11
while being triboelectrically charged by the development blade
11
In addition, bias is applied to the development roller
10
. As a result, the developer t is adhered to the. peripheral surface of the photosensitive drum
6
, in a pattern which reflects the electrostatic latent image on the peripheral surface of the photosensitive drum
6
. Consequently, the latent image is developed into a developer image, or a visible image. Then, the developer image, or an image realized as a visible image, on the photosensitive drum
6
. is transferred onto the recording medium P by the transfer roller
12
as described above.
On the other hand, a small amount of developer remains adhered to the peripheral surface of the photosensitive drum
6
even after the image transfer. The cleaning station
4
is provided with an opening
13
which faces the Photosensitive drum
6
. On the upstream side of the opening
13
, a squeezer sheet
14
is positioned in contact with the photosensitive drum
6
, being tilted in a manner to conform to the moving direction of the peripheral surface of the photosensitive drum
6
. On the downstream side of the opening
13
, a cleaning blade
15
as a cleaning member is disposed in contact with the peripheral surface of the photosensitive drum
6
, being tilted in a manner to contradict the moving direction of the peripheral surface of the photosensitive drum
6
. With the provision of the above arrangement, the developer t on the photosensitive drum
6
first slips through the interface between the squeezer sheet
14
and photosensitive drum
6
, is scrapped away from the peripheral surface of the photosensitive drum
6
by the cleaning blade
15
, and then, is collected in the cleaning means containing portion
16
. Thus, the portion of the peripheral surface of the photosensitive drum
6
, which has just passed the cleaning blade
15
, has no developer t, and is used for the image formation process during the following rotation of the photosensitive drum
6
.
There is also a removed developer storing portion
17
in the cleaning means containing portion
16
. The removed developer storing portion
17
is positioned at approximately the same level, above the developer container
3
. The recovered developer is stored in this removed developer storing portion
17
as it is recovered. Also in the cleaning means containing portion
16
, a conveying member
18
for conveying the removed developer, that is, the developer scraped away from the photosensitive drum
6
by the cleaning blade
15
, to the removed developer storing portion
17
, is located. The conveying member
18
extends across practically the entirety of the cleaning means containing portion
16
, in terms of the longitudinal direction. It comprises a metallic plate
19
, which serves as the sheet mount as well as a counter balance, and a sheet
20
of polyethylene-terephthalate (PET), or the like, attached to the metallic plate
19
. With the provision of the above described arrangement. after being recovered onto the cleaning blade
15
, the removed developer t is stored into the removed developer storing portion
17
.
Next, referring to
FIGS. 2 and 3
, the method for driving the cartridge
1
will be described. The development roller
10
is provided with a gear
10
a
, which is attached to one of the longitudinal end of the development roller
10
, and the rotational axis of which coincides with that of the development roller
10
. The stirring member
8
is provided with a gear
8
a
, which is fixed to the stirring member
8
, on the same side as the gear
10
a
, and rotates with the stirring member
8
. Further, the conveying member
18
is provided with a gear
18
a
, which is fixed to the conveying member
18
in the same manner as the gears
10
a
and
8
a.
The development unit which comprises the development station
2
and developer container
3
is provided with a gear
21
, which is rotatably attached to the side wall of the development unit. To this gear
21
, a driving force is transmitted from a gear
22
(
FIG. 5
) provided on the apparatus main assembly side. The driving force inputted into the gear
21
is transmitted to the aforementioned gear
10
a
by way of idler gears
23
and
24
. The idler gear
24
transmits a driving force to the aforementioned gear
8
a
through an idler gear
25
. Further, to the gear
18
a
, the driving force inputted into the aforementioned gear
21
is transmitted by way of the idler gear
23
and an idler gear
26
.
With the provision of the above described structural arrangement, the gear
10
a
for transmitting the driving force to the development roller
10
and the gear
18
a
for transmitting the driving force to the aforementioned conveying member
18
can be positioned adjacent to each other, enabling the gear
18
a
to receive the driving force from the driving system comprising the gear
21
, gear the
10
a
, and the gears between them. Therefore, the number of gear trains can be reduced to reduce the space necessary for the gear trains.
Next, referring to
FIGS. 4 and 5
, the installation of the cartridge
1
into the apparatus main assembly
101
, and the removal of the cartridge
1
from the apparatus main assembly, will be described, and the positioning of the cartridge
1
relative to the apparatus main assembly
101
will be described. The cartridge
1
is installed into, or removed from, the apparatus main assembly
101
, using a handle
27
of the shell portion of the cartridge
1
. A user installs the cartridge
1
into the cartridge space in the apparatus main assembly, by holding this handle
27
. With the provision of the following positioning mechanism, and guiding mechanism, the cartridge
1
can be accurately installed into, and positioned relative to, the apparatus main assembly
101
.
The external frame
1
a
of the cartridge
1
is provided with a flanges
28
for positioning the cartridge
1
, and a pair of ribs
29
which prevent the skewing of the cartridge
1
, and serve as guides, during the installation of the cartridge
1
into the apparatus main assembly
101
. On the other hand, the base
108
of the apparatus main assembly
102
is provided with a pair of guiding slots
30
which guide the aforementioned ribs
29
while controlling the skewing of the cartridge
1
, and a positioning portion
31
for position the cartridge
1
relative to the apparatus main assembly.
Further, the external frame portion
10
a
is provided with a slot
32
, through which the tooth flank of the gear
21
is partially exposed. During the insertion of the cartridge
1
into the apparatus main assembly
101
, as the flange
28
comes into contact with the positioning portion
31
, the exposed portion of the tooth flank of the gear
21
meshes with the gear
22
, making it possible for the driving force to be transmitted.
One of the longitudinal ends of the photosensitive drum
6
is provided with a coupling means (unillustrated), the axial line of which coincides with that of the photosensitive drum
6
, and which is integral with the photosensitive drum
6
, whereas the apparatus main assembly
101
is provided with a driving force inputting means (unillustrated), which is different from the gear
22
. Also during the insertion of the cartridge
1
into the apparatus main assembly
101
, as the flange
28
comes into contact with the positioning portion
31
, that is, as the flange
28
reaches a predetermined position, the driving force inputting means transmits the driving force to the coupling means integral with the photosensitive drum. Incidentally, the coupling means may be either a gear-type coupling or a jaw-type coupling.
Since the means for driving the photosensitive drum
6
, the means for driving the development roller
10
, and the mechanism for driving the development roller
10
, the stirring member
8
, and the conveying member
18
, are independently provided, it does not occur that the fluctuation in the rotation of the stirring member
8
and/or conveying member
18
, and the vibrations of the stirring member
8
and/or conveying means
18
, are directly transmitted to the means for driving the photosensitive drum
6
. Therefore, even if the accumulation of the removed developer increases the amount of the load which applies to the conveying member
18
, the rotation of the photosensitive drum
6
is not likely to be affected.
Embodiment 2
Referring to
FIG. 6
, the process cartridge in this embodiment of the present invention will be described. The portions of the process cartridge in this embodiment, the descriptions of which will be the same as those of the process cartridge in the first embodiment, will be given the same referential codes and their actual descriptions will be omitted here. Also in this embodiment, a conveying member
18
for conveying the removed developer from the top surface of a cleaning blade
15
to a removed developer storing portion
17
, is provided in the cleaning means containing portion
16
as in the first embodiment.
The transmission of the driving force to the gear
10
a
of a development roller
10
, and the gear
8
a
of a stirring member
8
, is the same as that in the first embodiment, except for a minor difference. That is, in the first embodiment, the driving force is transmitted from the gear
21
to the gear
18
a
by way of idler gears
23
and
26
, whereas in this embodiment, the driving force is transmitted to gear
18
a
from the gear
8
a
by way of gears
26
and
33
.
The provision of the above described structural arrangement makes it possible for the gear
18
a
to receive the driving force from the driving mechanism comprising the gears from gear
21
to gear
10
a
. Therefore, the same effects as those in the first embodiment can be obtained.
Embodiment 3
The process cartridge and electrophotographic image forming apparatus in this third embodiment of the present invention will be described with reference to the appended drawings.
FIG. 7
is a drawing for showing the general structure of the electrophotographic image forming apparatus in this embodiment, and
FIG. 8
is a sectional view of the process cartridge in this embodiment.
FIG. 9
is a perspective view of the partially disassembled process cartridge in this embodiment, and
FIG. 10
is a perspective view of the process cartridge as seen from above, with the walls of the removed developer storing portion and driving force transmission mechanism partially removed
FIG. 11
is a drawing for showing how the first and second frame portions are joined, and
FIG. 12
is a drawing for showing the drum driving force transmitting portion on the cartridge side and the drum driving force transmitting portion on the apparatus main assembly side.
FIG. 13
is a drawing for showing the connecting member of the driving force transmitting mechanism of the development unit, and
FIG. 14
is a drawing for showing the driving force transmitting mechanism on the process cartridge side.
FIG. 15
is a drawing for showing the reaction of the driving force transmitting mechanism on the process cartridge side when the first frame portion pivots.
(Electrophotographic Image Forming Apparatus)
First, referring to
FIG. 7
, the overall structure of the electrophotographic image forming apparatus will be described. The image forming apparatus
130
illustrated in
FIG. 7
is a full-color laser beam printer which employs an electrophotographic image forming method. In the main assembly
150
of this image forming apparatus
130
, four cartridge spaces
150
a
-
150
d
are provided, being aligned in the vertical direction, into which cartridges
40
are removably installed. All of the cartridges
40
placed in their own cartridge spaces are exactly the same in structure, but are different in the color of the developer t stored therein. More specifically, the cartridge space
150
a
holds a cartridge
40
a
in which developer t of cyan color is stored; the cartridge space
150
b
holds a cartridge
40
b
in which developer t of yellow color is stored; the cartridge space
150
c
holds a cartridge
40
c
in which developer t of magenta color is stored; and the cartridge space
150
d
holds a cartridge
40
d
in which developer t of black color is stored.
With the four process cartridges
40
a
-
40
d
properly placed in the main assembly
150
of the image forming apparatus
130
, four photosensitive drums
44
a
-
44
d
align in the vertical direction. Photosensitive drums
44
are rotated in the counterclockwise direction in the drawing. Adjacent to the peripheral surfaces of the photosensitive drums
44
a
-
44
d
, charge rollers
45
a
-
45
d
for uniformly charging the peripheral surfaces of the photosensitive drums
44
a
-
44
d
, development unit
42
a
-
42
d
for developing an electrostatic latent image; an electrostatic transferring apparatus
134
for transferring the developer image on each photosensitive drum
44
onto a recording medium P, and cleaning members
46
a
-
46
d
for removing the developer remaining on the photosensitive drums
44
a
-
44
d
, are disposed, correspondingly, in the listed order in terms of the rotational directions of the photosensitive drums
44
a
-
44
d
.
Referential codes
131
a
-
131
d
designate scanner units which form an electrostatic latent image on the corresponding photosensitive drums
44
a
-
44
d
by projecting a laser beam onto the peripheral surface of the corresponding photosensitive drums
44
a
-
44
d
, while modulating the laser beam according to image information.
Each cartridge
40
integrally comprises the photosensitive drum
44
, a charge roller
45
, a development unit
42
, and a cleaning member
46
. The cartridge
40
will be described later in detail.
The photosensitive drum
44
comprises an aluminum cylinder, for example, with a diameter of 30 mm, and a layer of organic, photoconductive material (OPC based photosensitive drum) coated on the peripheral surface of the aluminum cylinder. The photosensitive drum
44
is rotatably supported, at its longitudinal ends, by supporting members. As a driving force is transmitted to one of the longitudinal ends of the photosensitive drum
44
from a driving motor (unillustrated), the photosensitive drum
44
rotates in the counterclockwise direction in the drawing.
The charge roller
45
is an elastic roller and is of a contact type. In other words, as charge bias is applied to the charge roller
45
, with the charge roller
45
placed in contact with the peripheral surface of the photosensitive drum
44
, and the peripheral surface of the photosensitive drum
45
is uniformly charged.
The scanner units
131
a
-
131
d
are positioned at about the same levels as the corresponding photosensitive drums
44
a
-
44
d
. Beams of light modulated with image signals are projected from laser diodes (unillustrated) upon polygon mirrors
132
a
-
132
d
, which are being rotated at a high speed. The beams of the image forming light, or the beams of light modulated with image signals, are reflected by the polygon mirrors
132
a
-
132
d
, and are focused upon the peripheral surfaces of the photosensitive drum
44
a
-
44
d
through focusing lenses
133
a
-
133
d
, selectively exposing the peripheral surfaces of the photosensitive drums
44
a
-
44
d
. As a result, an electrostatic latent image is formed on the peripheral surface of each of the photosensitive drums
44
a
-
44
d.
As described above, the development unit
42
contains one developer among the yellow, magenta, cyan, and black developers t. The developer is coated on the peripheral surface of the development roller
51
, that is, a developing member, while charging the developer. Also, a development bias is applied to the development roller
51
positioned so that the peripheral surface of the development roller
51
becomes microscopically close to, and parallel to, the peripheral surface of the photosensitive drum
44
on which a latent image is present. As a result, developer is transferred onto the peripheral surface of the photosensitive drum
44
, across the areas corresponding to the low potential level portions of the electrostatic latent image. Consequently, a developer image is formed (developer) on the photosensitive drum
44
.
An endless belt
135
is positioned so that it remains in contact with all of the photosensitive drums
44
a
-
44
d
while it is circularly driven. The belt
135
is approximately 700 mm in circumference and is formed of film with a thickness of 150 μm. It is stretched around four rollers: a driver roller
136
, follower rollers
137
a
and
137
b
, and a tension roller
138
, and Is circularly driven in the direction indicated by an arrow mark X in the drawing. The recording medium P is kept pressed directly upon the outwardly facing surface of the belt
135
by a roller
144
, and electrical voltage is applied between the belt
135
and roller
144
to induce electrical charge between the recording medium P, which is dielectric, and the dielectric layer of the belt
135
. As a result, the recording medium P is electrostatically adhered to the outwardly facing surface of the belt
135
, assuring that the recording medium P is conveyed, being kept properly positioned, to the interface (transfer station) between the belt
135
and the photosensitive drum
44
.
Within the loop of the belt
135
, transfer rollers
139
a
-
139
d
are positioned, being kept in contact with the belt
135
, at the points corresponding to the photosensitive drums
44
a
-
44
d
, by a predetermined amount of pressure. Positive electrical charge is applied from these transfer rollers
139
to the recording medium P through the belt
135
. The developers images on the photosensitive drums
44
a
20
44
d
, which are negative in polarity, are transferred one after another onto the recording medium P while the recording medium P is conveyed in contact with the photosensitive drums
44
a
-
44
d
, by the electrical fields generated by these electrical charges.
A conveying portion
140
is a portion for conveying the recording medium P. In a sheet feeding cassette
141
, plural sheets of recording medium are stored. During an image forming operation, a feeding roller
142
is rotationally driven to feed out the plural sheets of recording medium and convey them forward, one by one, in coordination with the progression of the image forming operation. As the recording medium P is conveyed, it bumps against a pair of registration rollers
143
, being thereby straightened if it were skewed. Then, the recording medium P is released to the belt
135
by the pair of registration rollers
143
in synchronism with the rotation of the belt
135
, that is, in synchronism with the leading edges of the developer images on the photosensitive drums
44
a
-
44
d
. More specifically, the pair of registration rollers
143
begins to be rotated with such a timing that the leading edge of the developer image on the photosensitive drum
44
a
, or the most upstream photosensitive drum, arrives at the interface between the photosensitive drum
44
a
and belt
135
, at the same time as the leading edge of the recording area of the recording medium P on the belt
135
arrives at the interface between the photosensitive drum
44
a
and belt
135
.
After the transfer of the developer image onto the recording medium P, the recording medium P separates from the belt
135
due to the curvature of the driving roller
136
, and is conveyed into a fixing station
145
, which is where the plural developer images on the recording medium P are fixed to the recording medium P. More specifically, the fixing station
145
comprises a heat roller
146
, and a pressure roller
147
which is kept pressed upon the heat roller
146
to assure that heat and pressure is properly applied to the recording medium P. As the recording medium P, on which the transferred developer images are borne unfixed, is passed through the fixing station
145
, the developer is melted by the heat and fixed as a full-color image to the recording medium P by the pressure. After the fixation of the developer images, or the formation of the full-color image, the recording medium P is discharged out of the apparatus main assembly through a delivery station
149
by a pair of discharge rollers
148
.
(Process Cartridge)
Next, referring to
FIGS. 8-15
, the cartridge
40
(
40
a
-
40
d
) in this embodiment will be described. This cartridge
40
comprises a drum unit
41
, which is enclosed in the first frame portion, and a development unit
42
, which is enclosed in the second frame portion. As will be described later, the two units are connected by a pair of pins so that the two units are rendered pivotal relative to each other about a pivotal axis
43
which coincides with the axes of the pair of pins.
(First Frame Portion)
Referring to
FIG. 8
, the drum unit
41
enclosed in the first frame portion contains a photosensitive drum
44
, which is rotatably supported by the drum unit
41
with the use of a shaft
44
a
. In addition, the drum unit
41
contains a charge roller
45
for uniformly charging the peripheral surface of the photosensitive drum
44
, a cleaning member
46
for removing the developer remaining on the photosensitive drum
44
by making contact with the photosensitive drum
44
, a removed developer storing portion
47
located above a developer storing portion
52
, which will be described later, and a removed developer conveying mechanism
48
. Further, the drum unit
41
has a pair of holes
41
a
(
FIG. 9
) for connecting the drum unit
41
and development unit
42
. The center lines of the holes
41
a
coincide with the pivotal axis
43
.
Incidentally, a term “above” is used with reference to such a condition that the cartridge
40
is properly seated in the apparatus main assembly
150
.
As described above, the developer which remains on the photosensitive drum
44
after image transfer is scraped away by the cleaning member
46
, and the removed developer is conveyed into the removed developer storing portion
47
by the removed conveying mechanism
48
.
The removed developer conveying mechanism
48
is provided with a developer advancing plate
49
, or a removed developer conveying member, which is rotatably attached to a crank
50
rotatably supported by the removed developer storing portion
47
. The crank
50
is formed of a piece of metallic rod, and has a rotational diameter of 5 mm. The rotation of the crank
50
causes the developer advancing plate
49
to reciprocally move in the direction (direction H indicated by arrow mark in
FIG. 10
) to convey the removed developer from the adjacencies of the cleaning member
46
to the removed developer storing portion
47
. The developer advancing plate
49
is a piece of metallic plate with a thickness of 1 mm, and is provided with partitions
49
a
for conveying the developer forward.
Incidentally, a screw may be employed as the removed developer conveying member, although the developer advancing plate
49
is employed in this embodiment.
(Second Frame Portion)
Referring to
FIG. 8
, the development unit
42
enclosed in the second frame portion is provided with a development roller
51
as a developing member, a developer storing portion
52
which stores developer of relevant color. and a frame portion
54
for developing means. The developer storing portion
52
is located below the removed developer storing portion
47
, and contains stirring members
53
a
and
53
b
which double as a developer sending means.
Incidentally, a term “below” is used with reference to a condition in which the cartridge
40
is properly seated in the apparatus main assembly.
The developer in the developer storing portion
52
is delivered to a developer supplying roller
55
within the developing means frame portion
54
by a stirring member
53
. Then, the developer is adhered to the peripheral surface of the development roller
51
, which is rotating in the clockwise direction (direction of arrow mark Y), by the developer supplying roller
55
, which is rotating in the clockwise direction (direction of arrow mark Z), and a development blade
56
kept pressed upon the peripheral surface of the development roller
51
. As the developer is adhered to the peripheral surface of the development roller
51
, it is given electrical charge.
(Connection Between First and Second Frame Portions)
Referring to
FIG. 9
, the development unit
42
(second frame portion) is provided with a pair of bearing members
57
and
58
, which are located at the longitudinal ends of the development unit
42
(longitudinal ends of development roller
51
), one for one, for keeping the development unit
42
connected to the drum unit
41
(first frame portion). The bearing members
57
and
58
are provided with holes
57
a
and
58
a
with a bearing surface, respectively. The central axes of the holes
57
a
and
58
a
coincide with the pivotal axis
43
. Through these holes
57
a
and
58
a
, pins
43
a
are inserted into the holes
41
a
with which the drum unit
41
is provided, from the outward side of the bearing members
57
and
58
. As a result, the drum unit
41
and development unit
42
are connected in such a manner that they become pivotal relative to each other as shown in FIG.
11
. Further, the provision of a pair of compression springs
59
, which will be described later, between the two units assures that the peripheral surfaces of the photosensitive drum
44
and development roller
51
remain in contact with each other across the entire ranges of the two rollers in terms of their longitudinal directions.
More specifically, the pair of compression springs
59
are placed between the drum unit
41
and development unit
42
, as shown in
FIG. 8
, so that the photosensitive drum
44
and development roller
51
are kept pressed upon each other by the elasticity of the compression springs
59
.
(Driving Force Transmitting Mechanism)
Next, the driving force transmitting mechanism in the cartridge
40
will be described. In this embodiment, the driving force is independently transmitted to the drum unit
41
and development unit
42
of the cartridge
40
, from the apparatus main assembly.
Referring to
FIG. 9
, the drum unit
41
is provided with a drum driving coupling
60
, as a drum driving force transmitting member on the cartridge side, which is located at the longitudinal end of the photosensitive drum
44
. The axial line of the drum driving coupling
60
coincides with that of the photosensitive drum
44
. To this drum driving coupling
60
, the driving force is transmitted from a coupling
61
, as the driving force transmitting member, on the apparatus main assembly side.
Referring to
FIG. 12
, the coupling
60
on the cartridge side is in the form of a twisted, approximately equilateral, and triangular pillar, whereas the coupling
61
on the main assembly side is in the form of a twisted, approximately equilateral, and triangular hole. The cartridge side coupling
60
engages into the main assembly side coupling
61
in the direction parallel to the longitudinal direction of the photosensitive drum
44
. Then, as the main assembly side coupling
61
begins to rotate, the engagement of the cartridge side coupling
60
into the main assembly side coupling
61
becomes gradually deeper, following the twisted, equilateral, and triangular structures of the two coupling portions. By the time the apparatus side coupling
61
finishes rotating a maximum of 120 degrees, two couplings fully engage with each other, and the driving force begins to be transmitted to the photosensitive drum
44
. Incidentally, the rotational axis of the cartridge side coupling
60
coincides with the rotational axis of the photosensitive drum
44
.
Further, the drum unit
41
has a gear
62
attached to the shaft of the crank
50
of the removed developer conveying mechanism
48
, and an idler gear
63
meshed with the gear
62
(FIG.
14
).
The bearing member
57
, that is, the bearing member on the driven side, of the development unit
42
is provided with shafts
57
b
-
54
d
, around which a gear
64
, and idler gear
65
and
66
, as developing means driving force transmitting members, are fitted, correspondingly. The gear
64
is a helical gear, and driving force is transmitted to this gear
64
from a helical gear
67
as d developing means driving force transmitting member on the main assembly side, as shown in FIG.
14
. Incidentally, in terms of the direction perpendicular to the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
, the gear
46
is located at the same side of the cartridge
40
as the aforementioned cartridge side coupling
60
. Also in terms of the direction perpendicular to the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
, the gear
64
is on the inward side the cartridge side coupling
60
. Also in terms of the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
, the gear
64
is on the downstream side of the cartridge side coupling
60
.
Incidentally, the cartridge
40
is inserted into, or removed from, the apparatus main assembly
150
in the direction perpendicular to the axial line of the photosensitive drum
44
.
The axial line of the shaft
57
b
coincides with the axial line of the through hole
57
a
, the axial line of which coincides with the pivotal axis
43
. The gear
64
is positioned so that its axial line coincides with the axial lines (in other words, pivotal axis
43
) of the aforementioned connecting pins
43
a
by which the drum unit
41
and development unit
42
remain connected to each other.
To sum up, the cartridge
40
in this embodiment comprises: the drum unit
41
; the development unit
42
connected to the drum unit
41
with the use of the pins
43
a
in such a manner that the development unit
42
is rendered pivotal about the pins
43
a
; the photosensitive drum
44
with which the drum unit
41
is provided; the development roller
51
provided in the development unit
42
to develop the electrostatic latent image formed on the photosensitive drum
44
, with the use of the developer t; and the gear
64
as a developing means driving force transmitting member for receiving the driving force for rotating the development roller
51
, from the apparatus main assembly
150
, when the cartridge
40
is in the apparatus main assembly
150
. The gear
64
is positioned in such a manner that its axial line coincides with that of the aforementioned pins
43
a
. It receives a driving force from a direction approximately perpendicular to the longitudinal direction of the development roller
51
. It meshes with the aforementioned helical gear
67
, that is, one of the gears on the main apparatus side, which is provided in the apparatus main assembly
150
, on the downstream side with respect to the axial line of the gear
64
in terms of the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
. It should be noted here that as described above, the cartridge
40
is inserted into the apparatus main assembly
150
from the direction perpendicular to the axial line of the development roller
51
; the gear
64
is provided in the development unit
42
; the gear
64
is exposed through the opening
41
b
of the drum unit
41
; and the gear
64
meshes with the helical gear
67
by the exposed portion.
Incidentally, the direction from which the cartridge side coupling
60
, as a drum driving force transmitting member, receives a driving force from the apparatus main assembly
150
is perpendicular to the direction from which the gear
64
receives a driving force from the apparatus main assembly
150
. With the provision of the above described structure arrangement, when a driving force is inputted into the gear
64
, the moment generated about the pivotal axis
43
by the force F generated by the meshing between the helical gear
67
and gear
64
remains small. In other words, positioning the gear
64
in such a manner that the axial line of the gear
64
coincides with the axial lines of the pins
43
a
which connect the drum unit
41
and development unit
42
, prevents the position of the development unit
42
from changing. This, in turn, prevents the backlash between the gear
64
and helical gear
67
from changing. As a result, a stable image forming operation is possible. Further, when driving force is transmitted from the apparatus main assembly
150
to the development unit
42
, the moment which otherwise will be generated as the driving force is inputted from the apparatus main assembly
150
, is not generated, and therefore, an unsatisfactory image, the cause of which is traceable to cartridge-frame deformation, is not produced.
After being inputted into the gear
64
, the driving force is divisively transmitted. In other words, a part of the driving force inputted into that is transmitted to the development roller
51
, and the stirring member
53
, as well as the removed developer conveying mechanism
48
of the drum unit
41
, by way of driving force transmitting means, or the gear trains.
More specifically, after being inputted into the gear
64
, a part of the driving force is transmitted to the gear
68
attached to one end of the development roller
51
, and the gear
69
attached to one end of the developer supplying roller
55
, by way of the idler gear
65
and
66
which make up the first gear train, and rotates the development roller
51
and developer supplying roller
55
. Incidentally, the idler gear
65
is a step gear, and reduces the rotational velocity of driving force.
Another part of driving force is transmitted to the developer stirring gear
70
a
of the stirring member
53
a
to rotate the stirring member
53
a
, and then is further transmitted, by way of the idler gear
71
, to the developer stirring gear
70
b
of the stirring member
53
b
to rotate the stirring member
53
b.
From the idler gear
71
, the driving force is divisively transmitted. That is, a part of the driving force delivered to the idler gear
71
is transmitted to the idler gear
63
of the drum unit
41
through the idler gear
72
. As described above, the idler gear
63
is meshed with the gear
62
attached to the crank
50
of the removed developer conveying mechanism
48
, and therefore, transmits the driving force to the crank
50
, which in turn transmits the driving force to the developer advancing plate
49
. In other words, a part of the driving force inputted into the gear
64
of the development unit
42
is transmitted to the developer advancing plate
49
, that is, the removed developer conveying member of the drum unit
41
, by way of the driving force transmitting means, that is, the gear train (gears
65
,
70
a
,
71
,
72
,
63
and
62
), and reciprocally moves the developer advancing plate
49
. The idler gears
71
and
63
are stepped, and reduce the rotational velocity of driving force.
It should be noted here that the gears
70
a
,
71
,
70
b
,
72
,
62
and
63
make up the second gear trains. The gears
64
,
65
,
66
,
68
,
69
,
70
a
,
70
b
,
71
and
72
are attached to development unit
42
, and the gears
67
,
62
and
63
are attached to the drum unit
41
.
As described above, according to this embodiment, the means for driving the photosensitive drum
44
is rendered separate from the system for driving the development roller
51
, the stirring member
53
, and the developer advancing plate
49
. Therefore, it does not occur that the fluctuations in the rotational velocity, and vibrations, of the stirring member
53
and developer advancing plate
49
, are directly transmitted to the photosensitive drum
44
. Thus, even when the accumulation of the removed developer results in the increased load upon the developer advancing plate
49
, the rotation of the photosensitive drum
44
is not affected by the increase.
Further, the development unit
42
pivots relative to the drum unit
41
. Thus, the idler gear
72
of the development unit
42
also pivots relative to the idler gear
63
of the drum unit
41
. Therefore, a structural arrangement is made to place the pivotal axis
43
, and the axial lines of the idler gears
72
and
63
, in the same plane as shown in FIG.
15
. With this arrangement, the idler gears
72
and
63
do not interfere with the pivoting of the development
42
relative to the drum unit
41
, and the backlash between the two gears becomes minimum.
The cartridge
40
is provided with an handle
40
a
, which is located on the photosensitive drum side. This handle
40
a
is grasped by a user to install, or remove, the cartridge
40
into, or from, one of the aforementioned cartridge spaces
150
a
-
150
d
in a direction perpendicular to the axial line of the photosensitive drum
44
. Thus, in terms of the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
, the gear
64
is positioned on the downstream side of the cartridge side coupling
60
. Also in terms of the direction in which the cartridge
40
is inserted into the apparatus main assembly
150
, the photosensitive drum
44
, the development roller
51
, and the crank
50
for driving the developer advancing plate
49
, are positioned in the listed order, listing from the upstream side.
In this embodiment, the through hole
57
a
, through which the shaft for the gear
64
is put, and the center line of which coincides with the pivotal
5
axis
43
, is provided in the bearing member
57
. However, a similar structure may be placed in the developing means frame portion
54
, or the developer storing portion
52
instead of the bearing member
57
.
With the provision of the above described structural arrangements, a process cartridge, and an image forming apparatus, in accordance with the present invention, do not suffer from the problem that the increase in the load placed upon the removed developer conveying member by the accumulation of the removed developer affects the rotation of the photosensitive drum.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
Claims
- 1. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus comprising:a first frame; a second frame rotatably coupled with said first frame; an electrophotographic photosensitive drum provided in said first frame; a developing member, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum with a developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a drum driving force receiving member, provided in said first frame, for receiving, from the main assembly of the apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus; a development driving force receiving member, provided in said second frame, for receiving, from the main assembly of said apparatus, a driving force for rotating said developing member when said process cartridge is mounted to the main assembly of the apparatus; and a driving force transmitting member, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the development driving force receiving member to rotate said removed developer feeding member.
- 2. A process cartridge according to claim 1, wherein said development driving force receiving member includes a gear, wherein the driving force received by said gear is transmitted to said removed developer feeding member by a gear train as said driving force transmitting member to rotate said removed developer feeding member.
- 3. A process cartridge according to claim 2, wherein said gear train transmits the driving force to a stirring member provided in a developer accommodating portion for accommodating the developer to be used for development to rotate said stirring member, wherein said developer accommodating portion and said stirring member are provided in said second frame.
- 4. A process cartridge according to claim 1, wherein said development driving force receiving member is disposed downstream of said drum driving force receiving member with respect to a mounting direction of mounting said process cartridge to the main assembly of the apparatus, and wherein said development driving force receiving member and said drum driving force receiving member are provided in the same side with respect to a direction crossing with the mounting direction, and said process cartridge is mounted to the main assembly of the apparatus in the direction crossing with an axial direction of said photosensitive drum.
- 5. A process cartridge according to claim 4, wherein said drum driving force receiving member is in the form of a coupling, and said development driving force receiving member is in the form of a helical gear, and wherein said helical gear is disposed inside said coupling in the direction crossing with the mounting direction.
- 6. A process cartridge according to claim 1, wherein said development driving force receiving member is disposed downstream of said drum driving force receiving member with respect to the mounting direction of mounting said process cartridge to the main assembly of apparatus, and wherein said photosensitive drum, a developing roller as said developing member and a crank for driving said removed developer feeding member are arranged in the order named from an upstream side toward a downstream side with respect to the mounting direction.
- 7. A process cartridge according to claim 6, wherein said first frame is provided with a developer accommodating portion for accommodating a developer to be used for development, wherein a removed developer accommodating portion for accommodating in the removed developer is disposed so as to he above said developer accommodating portion when said process cartridge is mounted to the main assembly of the apparatus, and wherein said removed developer feeding member is disposed in said removed developer accommodating portion.
- 8. A process cartridge according to claim 1 or 3, wherein said drum driving force receiving member is a cartridge coupling which is engageable with a main assembly coupling provided in the main assembly of the apparatus in the direction along a longitudinal direction of said photosensitive drum and receives a driving force for rotating said photosensitive drum.
- 9. A process cartridge according to claim 8, wherein said cartridge coupling is in the form of a substantially twisted triangular prism, and said main assembly coupling is a twisted hole having a substantially triangular shape cross-section, and wherein the driving force is transmitted through engagement between the twisted triangular prism and the twisted hole.
- 10. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus comprising:a first frame; a second frame rotatably coupled with said first frame; an electrophotographic photosensitive drum provided in said first frame; a developing member, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum with a developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a drum driving force receiving member, provided in said first frame, for receiving, from the main assembly of the apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus; a development driving force receiving member, provided in said second frame, for receiving, from the main assembly of said apparatus, a driving force for rotating said developing member when said process cartridge is mounted to the main assembly of the apparatus; and a driving force transmitting member, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the development driving force receiving member to rotate said removed developer feeding member, wherein said development driving force receiving member is disposed downstream of said drum driving force receiving member with respect to a mounting direction of mounting said process cartridge to the main assembly of the apparatus, and wherein said development driving force receiving member and said drum driving force receiving member are provided in the same side with respect to a direction crossing with the mounting direction, and said process cartridge is mounted to the main assembly of the apparatus in the direction crossing with an axial direction of said photosensitive drum, wherein said drum driving force receiving member is in the form of a coupling, and said development driving force receiving member is in the form of a helical gear, and wherein said helical gear is disposed inside said coupling in the direction crossing with the mounting direction, and wherein said first frame and second frame are rotatably coupled by a shaft, and said helical gear is coaxial with the shaft.
- 11. A process cartridge according to claim 10, wherein said development driving force receiving member is disposed downstream of said drum driving force receiving member with respect to the mounting direction of mounting said process cartridge to the main assembly of apparatus, and wherein said photosensitive drum, a developing roller as said developing member and a crank for driving said removed developer feeding member are arranged in the order named from an upstream side toward a downstream side with respect to the mounting direction.
- 12. A process cartridge according to claim 11, wherein said first frame is provided with a developer accommodating portion for accommodating a developer to be used for development, wherein a removed developer accommodating portion for accommodating in the removed developer is disposed so as to be above said developer accommodating portion when said process cartridge is mounted to the main assembly of the apparatus, and wherein said removed developer feeding member is disposed in said removed developer accommodating portion.
- 13. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus comprising:a first frame which is disposed such that it takes a relatively upper position when said process cartridge is mounted to the main assembly of the apparatus; a second frame coupled with said first frame for rotation about a shaft, wherein said second frame is disposed such that it takes a relatively lower position when said process cartridge is mounted to the main assembly of the apparatus; an electrophotographic photosensitive drum provided in said first frame; a developing roller, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum with a developer; a developer accommodating portion, provided in said second frame, for accommodating the developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a removed developer accommodating portion, provided in said first frame, for accommodating the developer removed by said cleaning member, said removed developer feeding member being disposed in said removing developer accommodating portion and being disposed such that it takes a position above said developer accommodating portion when said process cartridge is mounted to the main assembly of the apparatus; a cartridge coupling, provided in said first frame, to receiving, from the main assembly of apparatus, the driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus, wherein said cartridge coupling is disposed coaxially with said photosensitive drum; a cartridge helical gear, provided in said second frame, for receiving, from the main assembly of the apparatus, a driving force for rotating said developing roller when said process cartridge is mounted to the main assembly of the apparatus, wherein said cartridge helical gear is disposed downstream of said cartridge coupling with respect to a mounting direction of mounting said process cartridge to the main assembly of the apparatus, and wherein said cartridge helical gear disposed coaxially with said shaft, and said cartridge helical gear disposed inside of a position of said cartridge coupling with respect to a direction crossing with the mounting direction; and a gear train, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the cartridge helical gear to rotate said removed developer feeding member; wherein said photosensitive drum, said developing roller and a crank for driving said removed developer feeding member are disposed in the order named from an upstream side to a downstream side with respect to the mounting direction, and wherein said cartridge helical gear and said cartridge coupling are disposed at the same side with respect to a direction crossing with the mounting direction, and wherein said process cartridge is mounted to the main assembly of the apparatus in a direction crossing with an axis of said photosensitive drum.
- 14. A process cartridge according to claim 13, wherein said cartridge coupling is in the form of a substantially twisted triangular prism, and a main assembly coupling for transmitting the driving force to said cartridge coupling is a twisted hole having a substantially triangular shape cross-section, and wherein the driving force is transmitted through engagement between the twisted triangular prism and twisted hole.
- 15. A process cartridge according to claim 13 or 14, further comprising a stirring member for stirring the developer accommodated in said developer accommodating portion, wherein stirring member is accommodated in said developer accommodating portion and receives the driving force from said gear train.
- 16. A process cartridge according to claim 1 or 13, wherein a rotational center of said first frame and said second frame, a gear of said driving force transmitting member provided in said second frame, and a gear which is provided in said first frame and which is in meshing engagement with said gear of said driving force transmitting member, are substantially on a line.
- 17. An electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:(i) a main assembly drum driving force transmitting member; (ii) a main assembly development driving force transmitting member; (iii) a mounting portion for detachably mounting a process cartridge, said process cartridge including: a first frame; a second frame rotatably coupled with said first frame; an electrophotographic photosensitive drum provided in said first frame; a developing member, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum with a developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a drum driving force receiving member, provided in said first frame, for receiving, from the main assembly drum driving force transmitting member, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus; a development driving force receiving member, provided in said second frame, for receiving, from the main assembly development driving force transmitting member, a driving force for rotating said developing member when said process cartridge is mounted to the main assembly of the apparatus; and a driving force transmitting member, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the development driving force receiving member to rotate said removed developer feeding member.
- 18. An electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:(i) a main assembly coupling; (ii) a main assembly helical gear; (iii) a mounting portion for detachably mounting a process cartridge, said process cartridge including: a first frame which is disposed such that it takes a relatively upper position when said process cartridge is mounted to the main assembly of the apparatus; a second frame coupled with said first frame for rotation about a shaft, wherein said second frame is disposed such that it takes a relatively lower position when said process cartridge is mounted to the main assembly of the apparatus; an electrophotographic photosensitive drum provided in said first frame; a developing roller, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum; a developer accommodating portion, provided in said second frame, for accommodating the developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a removed developer accommodating portion, provided in said first frame, for accommodating the developer removed by said cleaning member, said removed developer feeding member being disposed in said removed developer accommodating portion and being disposed such that it takes a position above said developer accommodating portion when said process cartridge is mounted to the main assembly of the apparatus; a cartridge coupling, provided in said first frame, to receive, from said main assembly coupling, the driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus, wherein said cartridge coupling is disposed coaxially with said photosensitive drum; a cartridge helical gear, provided in said second frame, for receiving, from said main assembly helical gear, a driving force for rotating said developing roller when said process cartridge is mounted to the main assembly of the apparatus, wherein said cartridge helical gear is disposed downstream of said cartridge coupling with respect to a mounting direction of mounting said process cartridge to the main assembly of the apparatus, and wherein said cartridge helical gear is disposed coaxially with said shaft, and said cartridge helical gear is disposed inside of a position of said cartridge coupling with respect to a direction crossing with the mounting direction; and a gear train, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the helical gear to rotate said removed developer feeding member; wherein said photosensitive drum, said developing roller and a crank for driving said removed developer feeding member are disposed in the order named from an upstream side to a downstream side with respect to the mounting direction, and wherein said cartridge helical gear and said cartridge coupling are disposed at the same side with respect to a direction crossing with the mounting direction, and wherein said process cartridge is mounted to the main assembly of the apparatus in a direction crossing with an axis of said photosensitive drum.
- 19. An electrophotographic image forming apparatus for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:(i) a main assembly drum driving force transmitting member; (ii) a main assembly development driving force transmitting member; (iii) a mounting portion for detachably mounting a process cartridge, said process cartridge including: a first frame; a second frame rotatably coupled with said first frame; an electrophotographic photosensitive drum provided in said first frame; a developing member, provided in said second frame, for developing an electrostatic latent image formed on said photosensitive drum with a developer; a cleaning member, provided in said first frame, for removing the developer remaining on said photosensitive drum; a removed developer feeding member, provided in said first frame, for transporting the developer removed by said cleaning member; a drum driving force receiving member, provided in said first frame, for receiving, from the main assembly of the apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus; a development driving force receiving member, provided in said second frame, for receiving, from the main assembly of said apparatus, a driving force for rotating said developing member when said process cartridge is mounted to the main assembly of the apparatus; and a driving force transmitting member, provided in said second frame, for transmitting, to said removed developer feeding member, the driving force received from the main assembly of the apparatus by the development driving force receiving member to rotate said removed developer feeding member, wherein said development driving force receiving member is disposed downstream of said drum driving force receiving member with respect to a mounting direction of mounting said process cartridge to the main assembly of the apparatus, and wherein said development driving force receiving member and said drum driving force receiving member are provided in the same side with respect to a direction crossing with the mounting direction, and said process cartridge is mounted to the main assembly of the apparatus in the direction crossing with an axial direction of said photosensitive drum, wherein said drum driving force receiving member is in the form of a coupling, and said development driving force receiving member is in the form of a helical gear, and wherein said helical gear is disposed inside said coupling in the direction crossing with the mounting direction, and wherein said first frame and second frame are rotatably coupled by a shaft, and said helical gear is coaxial with the shaft.
- 20. An electrophotographic image forming apparatus according to claim 19, wherein a rotational center of said first frame and said second frame, a gear of said driving force transmitting member provided in said second frame, and a gear which is provided in said first frame and which is in meshing engagement with said gear of said driving force transmitting member are substantially on a line.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2000-000441 |
Jan 2000 |
JP |
|
2000-390010 |
Dec 2000 |
JP |
|
US Referenced Citations (12)