Information
-
Patent Grant
-
6671476
-
Patent Number
6,671,476
-
Date Filed
Thursday, February 20, 200321 years ago
-
Date Issued
Tuesday, December 30, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Morgan, Lewis & Bockius LLP
-
CPC
-
US Classifications
Field of Search
US
- 399 110
- 399 111
- 399 112
- 399 113
- 399 118
- 399 119
- 399 120
- 399 220
-
International Classifications
-
Abstract
A developer storage space into which developer is stored is segmented into a first developer storage portion 116a arranged at an upper portion of this developer storage space, and a second developer storage portion 116b arranged at a lower portion thereof, while sandwiching therebetween a window portion 120 which constitutes an optical scanning path. This first developer storage portion 116a is communicated with the second developer storage portion 116b via developer paths 122a and 122b, which are provided at both sides of the window portion 120. The developer derived from the first developer storage unit 116a is conducted to the developer paths 122a and 122b by the first stirring/transporting member 124, and then, is supplied to the second developer storage portion 116b through the developer paths 122a and 122b, and furthermore, is uniformly transported by the second stirring/transporting member 130 also to a central portion of a developing unit.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to an electro-photographic type image forming apparatus and a process cartridge used in this image forming apparatus.
2. Description of the Related Art
As a conventional image forming apparatus, such an image forming apparatus is well known in this technical field in which a process cartridge is detachably mounted on a main body of the image forming apparatus. As one of conventional process cartridges, such a process cartridge is known in which both a cleaning apparatus and a developing apparatus are relatively arranged in an upper/lower positional relationship, while sandwiching therebetween an optical scanning path.
In the image forming apparatus employing such a process cartridge, in such a mode that transferring/fixing operations are carried out while recording mediums are transported along a substantially vertical direction, the developing apparatus is arranged under the optical scanning path. As a result, in order to reduce the height of this image forming apparatus, since the developing apparatus is located on the lower side of the optical scanning path, the height of the developing apparatus is required to be decreased. Since the developing apparatus contains a developer storage unit for storing thereinto developer, the size of this developer storage unit must be reduced. However, while the developer storage capacity is maintained, it is practically difficult to make the developing apparatus compact.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process cartridge and an image forming apparatus using the process cartridge, which can be made compact, while a sufficiently large developer storage capacity is maintained.
To achieve the above-described object, a first feature of the present invention is realized by a process cartridge detachably mounted on a main body of an image forming apparatus, comprising: an image carrier; and a developing apparatus having a developer storage space, for developing a latent image formed on the image carrier to produce a visible image; in which the developer storage space is segmented into a first developer storage portion and a second developer storage portion along upper/lower directions, while sandwiching therebetween a latent image writing position of the image carrier into which the latent image is written; and also the first developer storage portion is communicated to the second developer storage portion via a developer path. Since the developer storage space is segmented into upper/lower portions while sandwiching therebetween the developer path, even when the developer storage capacity of the second developer storage portion located under the latent image writing position is reduced, the necessary amount of the developer can be replenished with the developer stored in the second developer storage portion.
In the case that, for instance, a scanning type laser exposing apparatus is employed as a means for forming a latent image, in order to secure an optical scanning path outputted from this scanning type laser exposing apparatus, a window portion which constitutes the optical scanning path is formed between the first developer storage portion and the second developer storage portion, and also, both the first developer storage portion and the second developer storage portion are separated from each other along the upper/lower direction while sandwiching therebetween this window portion. Also, developer paths may be preferably provided on the both sides of this window portion.
Preferably, the first developer storage portion is provided with a first stirring/transporting member which stirs/transports the developer from a center of the first stirring/transporting member to both sides thereof. This first stirring/transporting member may be constituted by, for example, a wire line material. Although the first stirring/transporting member may be formed in a crank shape, this first stirring/transporting member may be formed in a helical shape in such a manner that the wire line materials are wound from a center portion thereof (viewed from axial line direction) toward both edge portions thereof along different winding direction.
Preferably, the second developer storage portion is provided with a second stirring/transporting member which stirs/transports the developer from both side portions of the second stirring/transporting member to a center portion thereof. As a result, the amounts of the developer can be made equal to each other along the axial direction. It should be understood that when the developer owns good fluidity, this second stirring/transporting member need not employ a specific structure, but may be formed in, for instance, a crank shape.
Also, the present invention may cover an image forming apparatus having the process cartridge with employment of the above-explained construction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a sectional view for indicating an image forming apparatus according to an embodiment mode of the present invention.
FIG. 2
is a sectional view for representing a process cartridge according to an embodiment mode of the present invention.
FIG. 3
is a side view for showing a supply path of developer in the process cartridge according to the embodiment mode of the present invention.
FIG. 4
is a perspective view for indicating the process cartridge according to the embodiment mode of the present invention.
FIG. 5
is an exploded perspective view for indicating an image carrier unit of the process cartridge according to the embodiment mode of the present invention.
FIG. 6
is an exploded perspective view for representing a developing appliance unit of the process cartridge according to the embodiment mode of the present invention.
FIG. 7
is a perspective view for showing the developing appliance unit of the process cartridge according to the embodiment mode of the present invention.
FIG. 8
is an exploded perspective view of the developing appliance unit of the process cartridge according to the embodiment mode of the present invention, as viewed from a rear surface of the developing appliance unit.
FIGS. 9A
to
9
E are side views for indicating modifications of second stirring/transporting members employed in the process cartridge according to the embodiment mode of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to drawings, embodiment modes of the present invention will be described.
FIG. 1
schematically shows an image forming apparatus
10
according to an embodiment mode of the present invention. The image forming apparatus
10
contains a main body
12
of the image forming apparatus. An image forming section
14
is mounted on this image forming apparatus main body
12
. An ejection unit
16
(will be explained later) is provided at an upper portion of this image forming apparatus main body
12
, and also, for instance, two stages of paper supply units
18
a
and
18
b
are arranged at a lower portion of this image forming apparatus main body
12
. Furthermore, two stages of paper supply units
18
c
and
18
d
are arranged below the image forming apparatus main body
12
, while these paper supply units
18
c
and
18
d
are detachably mounted thereon as an optional paper supply unit.
Each of the paper supply units
18
a
to
18
d
owns a paper supply unit main body
20
and a paper supply cassette
22
into which paper is stored. The paper supply cassette
22
is slidably mounted with respect to the paper supply unit main body
20
, and is drawn out from this paper supply unit main body
20
along a front plane direction (namely, right direction of FIG.
1
). Also, a nudger roller
24
is arranged at an upper portion near an inner end of the paper supply cassette
22
, and both a retard roller
26
and a feed roller
28
are arranged in front of this paper supply roller
24
. Furthermore, feed rollers
30
are provided with the optionally-provided paper supply units
18
c
and
18
d
, and these feed rollers
30
may constitute a pair of feed rollers.
A transport path
32
corresponds to a paper path defined from the nudger roller
24
of the lowermost paper supply unit
18
d
up to an ejection port
34
. While this transport path
32
is located in the vicinity of a rear surface (namely, left side surface viewed in
FIG. 1
) of the image forming apparatus main body
12
, this transport path
32
owns such a portion which is formed along the substantially vertical direction from the feed roller
30
of the lowermost paper supply unit
18
d
up to a fixing apparatus
36
(will be discussed later). Both a transferring apparatus
42
(will be explained later) and an image carrier
44
(will be explained later) are arranged on an upper stream side of the fixing apparatus
36
of this transport path
32
. Furthermore, a register roller
38
is arranged on an upper stream side of both the transferring apparatus
42
and the image carrier
44
. In addition, an ejection roller
40
is arranged in the vicinity of an ejection port
34
of the transport path
32
.
As a result, the recording mediums which are fed out by the nudger roller
24
from the paper supply cassettes
22
of the paper supply units
18
a
to
18
d
are smoothly separated by the retard roller
26
and the feed roller
28
to be conducted to the transport path
32
, and then, are temporarily stopped by the register roller
38
. After proper timing is controlled, a developer image is transferred to the recording medium while the recording medium is penetrated between the transferring apparatus
42
and the image carrier
44
(will be explained later), and this transferred developer image is fixed on the fixing apparatus
36
, and then, the recording medium on which the fixed image has been formed is ejected from the ejection port
34
to the ejection unit
16
by the ejection roller It should be noted that when a double-surface printing mode is carried out, this recording medium is returned to an inversion path
48
. In other words, a front path portion of the transport path
30
as to the ejection roller
40
is separated into two paths, a switching craw
46
is provided at this separated path portion, and the inversion path
48
is formed from this separated path portion up to the register roller
38
. While transport rollers
50
a
to
50
c
are provided in this inversion path
48
, in the case of the double-surface printing mode, the switching claw
46
is switched to such a side that the inversion path
48
is opened. Then, the ejection roller
40
is inverted at a time instant when a front edge portion of a recording medium is engaged with the ejection roller
40
, so that this recording medium is conducted to the inversion path
48
, and then, is penetrated through the register roller
38
, the transfer apparatus
42
, the image carrier
44
, and the fixing apparatus
36
so as to be ejected from the ejection port
34
to the ejection unit
16
.
The ejection unit
16
owns an inclination unit
52
which is freely pivotable with respect to the image forming apparatus main body
12
. This inclination unit
52
is inclined in such a manner that an ejection port portion thereof is low and is gradually heightened toward a front surface direction (namely, right direction viewed in FIG.
1
). This ejection port portion is used as a lower end of the inclination unit
52
and a tip portion which is heightened is used as an upper end thereof. This inclination unit
52
is supported with respect to the image forming apparatus main body
12
in such a manner that this inclination unit
52
is freely pivotable, while the lower end thereof is located at a center. As indicated by a two-dot/dash line in
FIG. 1
, when this inclination unit
52
is rotated toward the upper direction so as to be opened, an opening unit
54
is formed, and a process cartridge (will be explained later)
64
can be detachably mounted via this opening unit
54
.
The image forming section
14
is made of, for instance, an electro-photographic type image forming unit. This image forming section
14
is arranged by the image carrier
44
constructed of a photosensitive material, a charging apparatus
56
, an optical writing apparatus
58
, a developing appliance
60
, a transferring apparatus
42
, a cleaning apparatus
62
, and a fixing apparatus
36
. The charging apparatus
56
is constituted by, for example, a charge roller capable of uniformly charging the image carrier
44
. The optical writing apparatus
58
writes a latent image in an optical manner on the image carrier
44
charged by the charging apparatus
56
. The developing appliance
60
develops the latent image of the image carrier
44
, which has been formed by the optical writing apparatus
58
, by way of developer so as to produce a visible image. The transferring apparatus
42
is constituted by, for example, a transfer roller which transfers the developer image by the developing appliance
60
to paper. The cleaning apparatus
62
is constituted by, for instance, a blade which cleans the developer left on the image carrier
44
. The fixing apparatus
36
is arranged by both a pressure-applying roller and a heating roller, by which the developer image which has been transferred onto the paper by the transferring apparatus
42
is fixed on this paper. The optical writing apparatus
58
is constructed of, for example, a scanning type laser exposing apparatus, and is arranged in parallel to the above-described paper supply units
18
a
to
18
d
, and is located in the vicinity of a front surface of the image forming apparatus main body
12
. As will be explained later, the optical writing apparatus
58
exposes the image carrier
44
by scanning light beams across the inner space of the developing appliance
60
. This exposing position of the image carrier
44
may constitute a latent image writing position “P”. It should be noted that in this embodiment mode, the scanning type laser exposing apparatus has been employed as the optical writing apparatus
58
. Alternatively, an LED (Light Emitting Diode), a surface emitting laser, and the like may be employed.
The process cartridge
64
is arranged by employing the image carrier
44
, the charging apparatus
54
, the developing appliance
60
, and the cleaning apparatus
62
in an integral body. This process cartridge
64
is arranged just under the inclination unit
52
of the ejection unit
16
, and as previously explained, is detachably mounted via the open portion
54
which is formed when the inclination unit
52
is opened.
This process cartridge
64
is detachably separated into an image carrier unit
66
and a developing appliance unit
68
. In the image carrier unit
66
, the image carrier
44
, the charging apparatus
54
, and the cleaning apparatus
60
are arranged. In the developing appliance unit
68
, the developing appliance
60
is arranged. The developing appliance unit
68
owns a developer storage space
70
which stores there into, for example, developer. An upper portion of this developer storage unit
70
belongs to such an area “A” which is surrounded by the inclination unit
52
, a horizontal plane extended from the lower end of the inclination unit
52
, and also, a vertical plane extended from the upper end of this inclination unit
52
as indicated by a two-dot/dash line in FIG.
1
. Also, an upper wall plane
72
which constitutes the developer storage space
70
is formed in such a manner that this upper wall plane
72
is located in parallel to the inclination unit
52
and along this inclination unit
52
. Also, a plurality of ribs
74
are formed on a lower surface of the inclination unit
52
in such a way that these plural ribs
74
are positioned in parallel to each other along the inclination direction of the inclination unit
52
. Since these ribs
74
are formed, a flow path
76
is formed between the inclination unit
52
and the process cartridge
64
. This flow path
76
is employed so as to penetrate air therethrough, and this flow path
76
may disperse heat produced from the fixing apparatus
36
. Furthermore, a grip unit
78
is formed on the upper portion of the developer storage space
70
. This grip unit
78
is formed in such a manner that wall surfaces of both sides of the upper portion of the developer storage space
70
are entered into the inside thereof. When the process cartridge
64
is detachably mounted, this process cartridge
64
can be readily detachably mounted by gripping this grip unit
78
.
In
FIG. 2
to
FIG. 8
, a detailed construction of the above-described process cartridge
64
is indicated. As explained above, the process cartridge
64
is arranged by the image carrier unit
66
and the developing appliance unit
68
, and this image carrier unit
66
is coupled to the developing apparatus unit
68
via coupling pins
80
a
and
80
b
in such a manner that this image carrier unit
66
is freely pivotable with respect to the developing apparatus unit
68
. Also, both the image carrier unit
66
and the developing apparatus
68
are energized with each other by a tension spring
82
and a depression spring
84
, and a developing roller
86
is depressed against the image carrier
44
.
It should also be understood that a memory
88
for storing thereinto a total print number and the like is provided on a side surface of the process cartridge
64
(namely, side surface of one, or both image carrier unit
66
and developing appliance unit
68
).
The image carrier unit
66
owns a main body
90
of the image carrier unit
66
, and both the image carrier
44
and the charging apparatus
56
are supported by this image carrier unit main body
90
in such a manner that both the image carrier
44
and the charging apparatus
56
are rotatably supported by this image carrier unit main body
90
via bearing
92
a
and
93
b
used for the image carrier
44
, and bearings
94
a
and
94
b
used for the charging apparatus
56
, respectively. An one of the above-described bearing
94
a
and bearing
94
b
for the charging apparatus
56
own another function of a power supply portion. Also, for example, two fingers
96
a
and
96
b
are supported by the image carrier unit main body
90
in such a manner that these fingers
96
a
and
96
b
are freely pivotable with respect to this image carrier unit main body
90
. Since tip portions of these fingers
96
a
and
96
b
are depressed by a spring for the fingers
96
a
and
96
b
on the surface of the image carrier
44
, a recording medium which will wrap the image carrier
44
is stripped by these tip portions. Also, a developer collecting space
98
is formed above the cleaning apparatus (cleaning blade)
62
within the image carrier unit main body
90
, and thus, developer which has been scratched/dropped by the cleaning apparatus
62
is collected into this developer collecting space
98
. A paddle
100
is rotatably provided in this developer collecting space
98
. This paddle
100
is supported via a gear
102
for the paddle
100
by the image carrier unit main body
98
, and transports the developer which has been collected by being rotated to an inner side of the developer collecting space
98
. Also, a shutter
104
is provided at the upper portion of the image carrier unit main body
90
in such a manner that this shutter
104
can be freely opened/closed. This shutter
104
is supported via a shaft
106
for the shutter
104
with respect to the image carrier unit main body
90
in a freely movable manner. This shutter
104
closes an opening portion of the image carrier
44
before the process cartridge
64
is mounted, and is opened in order that the image carrier
44
is come out to the front in the case that the process cartridge
64
is mounted.
The developing appliance unit
68
contains a main body
112
of the developing appliance unit
68
which is constituted by jointing a front housing
108
to a rear housing
110
. An inner space of this developing appliance unit main body
112
is segmented into the above-described developer collecting space
70
and a developing unit
114
in which the developing roller
86
is arranged. The developer collecting space
70
is separated into a first developer storage portion
116
a
and a second developer storage portion
116
b
via a partition wall
118
, while a horizontal line extended from the latent image writing position “P” is defined as a boundary. This horizontal line corresponds to a scanning optical path originated from the optical writing apparatus
58
. The first developer collecting portion
116
a
is located at an upper portion of the developer collecting space
70
, whereas the second developer storage portion
116
b
is located at a lower portion thereof. A developer storage capacity of the first developer storage unit
116
a
is made larger than a developer storage capacity of the second developer storage unit
116
b.
As shown in
FIG. 3
, the partition wall
118
constitutes a window portion
120
having, for example, a rectangular shape, which forms the optical scanning path defined from the optical writing apparatus
58
. Also, this partition wall
118
constitutes developer paths
122
a
and
122
b
in connection with the developing appliance unit main body
112
on both sides of this window portion
120
. Both the developer paths
122
a
and
122
b
cause the first developer storage portion
116
a
to be communicated with the second developer storage portion
116
b
. In the first developer storage portion
116
a
, as previously explained, a first stirring/transporting member
124
is rotatably arranged, and also an upper portion of this first developer storage portion
116
b
is arranged within the area “A.”
As indicated in FIG.
3
and
FIG. 6
, the first stirring/transporting member
124
contains a shaft portion
126
, and winding portions
128
a
and
128
b
which are formed in helical shapes along different winding directions which are directed from a center portion (viewed along axial line direction) of this shaft portion
126
to both edge portions thereof. This shaft portion
126
and the winding portions
128
a
,
128
b
are constituted by a single wire material. As a consequence, when this first stirring/transporting member
124
is rotated, the developer stored in the first developer storage portion
116
a
can be supplied to the developer paths
122
a
and
122
b
provided on both sides along the axial line direction, and thus, the developer maybe supplied via these developer paths
122
a
and
122
b
to the second developer storage portion
116
b.
A second stirring/transporting member
130
is rotatably arranged at a lower position of the first stirring/transporting member
124
within the second developer storage unit
116
b
. As shown in FIG.
3
and
FIG. 6
, this second stirring/transporting member
130
is constituted as a screw shaft which is constituted by a shaft portion
132
, and also screw portions
134
a
and
134
b
. These screw portions
134
a
and
134
b
are formed from edge portions (viewed along axial direction) of this shaft portion
132
to a center portion thereof along different directions. As a consequence, when this second stirring/transporting member
130
is rotated, larger amounts of the developer are transported from the both-sided developer paths
122
a
and
122
b
toward the center direction, and then the developer is uniformly dispersed to be supplied to a subsequent third stirring/transporting member
136
.
Furthermore, both a third stirring/transporting member
136
and a fourth stirring/transporting member
138
are arranged in the second developer storage portion
116
b
. The third stirring/transporting member
136
transports the developer to the fourth stirring/transporting member
138
, while this third stirring/transporting member
136
owns a shaft portion
140
, and a plate-shaped portion
142
, one edge of which is fixed on this shaft portion
140
, and also which is extended along a circumferential direction. The fourth stirring/transporting member
138
transports the developer which has been transported by the third stirring/transporting member
142
to the developing roller
86
, and also, mixes this new developer with the developer which has been scratched/dropped from the developing roller
86
.
As is well known in the field, the developing roller
86
is constructed in such a manner that a sleeve is wound on a magnet roller, and tracking caps
144
a
and
144
b
are provided on both sides of the magnet roller. These tracking caps
144
a
and
144
b
are made in contact to the image carrier
44
, and as explained in the above description, a developing gap may be secured by depressing these tracking caps
144
a
and
144
b
against the image carrier
44
by both the tension spring
82
and the depression spring
84
. A layer thickness restricting member
146
made of, for instance, a resin is made in contact with the developing roller
86
. A thickness of a developer layer adhered on the surface of the developing roller
86
is restricted by this layer thickness restricting member
146
. Also, a side surface of this developing roller
86
is sealed by a developing portion sealing member
148
.
It should also be noted that reference numerals
150
a
and
150
b
indicate developer caps which are detachably mounted on the developing appliance unit main body
112
. Since these developer caps
150
a
and
150
b
are pulled out, the developer is supplied to either the first developer storage unit
116
a
, or the second developer storage unit
116
b.
In the drive system of the process cartridge
64
, drive force is transferred from the side of the image carrier
44
, and then, is transferred via a developing roller gear
152
, a gear
154
for the respective first to fourth stirring/transporting members, and an idle gear
156
to the developing roller
86
and also to the respective first to fourth stirring/transporting members
124
,
130
,
136
, and
138
. A stirring/transporting member sealing member
158
is inserted into a bearing portion of the stirring/transporting member gear
154
. Furthermore, a gear cover
159
is provided on the side surface of the developing appliance unit main body
112
, while this gear cover
159
covers the gear
154
for the respective stirring/transporting members and the idle gear
156
.
Next, operations of the image forming apparatus according to the above-described embodiment mode will now be described.
While the image carrier
44
is uniformly charged by the charging apparatus
56
, light emitted from the optical writing apparatus
58
is irradiated onto this charged image carrier
44
in response to an image signal, and then, a latent image is formed at the latent image forming position “P” thereof. The light emitted from the optical writing apparatus
58
passes through the process cartridge
64
via the window portion
120
of the process cartridge
64
. The latent image which has been formed on the image carrier
44
by this optical writing apparatus
58
is developed by the developer of the developing appliance
60
so as to produce a visible image.
While the developer has been stored in both the first developer storage portion
116
a
and the second developer storage portion
116
b
, the developer stored in the first developer storage portion
116
a
is transported to both sides by rotating the first stirring/transporting member
124
, and then both the developer located on the both sides is transported via the two developer paths
122
a
and
122
b
to the second developer storage unit
116
b
. Furthermore, the developer of the second developer storage portion
116
b
is uniformly dispersed by rotating the second stirring/transporting member
130
, and then, the uniformly dispersed developer is transported to the developing unit
114
by the third stirring/transporting member
136
and the fourth stirring/transporting member
138
. In this developing unit
114
, the transported developer is adhered onto the developing roller
86
, the layer thickness of the adhered developer is restricted by the layer thickness restricting member
146
, the thickness restricted developer is transported up to a developing position located opposite to the image carrier
44
, and then, an image made of the developer is formed in correspondence with the latent image of the image carrier
44
.
On the other hand, one of the paper supply units
18
a
to
18
d
is selected in response to a size signal and the like, recording mediums stored in one of these paper supply cassettes
22
are fed out by the nudger roller
24
, and these recording mediums are smoothly separated by the retard roller
26
and the feed roller
28
so as to conduct a recording medium to the transport path
32
. Then, this conducted recording medium is temporarily stopped by the register roller
38
, and thereafter, this recording medium is conducted between the transferring apparatus
42
and the image carrier
44
at proper timing.
When the recording medium is conducted between the transferring apparatus
42
and the image carrier
44
in this manner, the developer on the image carrier
44
is transferred to the recording medium by the transferring apparatus
42
. This recording medium to which the developer has been transferred is penetrated through the fixing apparatus
36
, and then is ejected from the ejection port
34
to the ejection unit
16
.
The recording medium is penetrated through the transport path
32
, and then is ejected to the ejection unit
16
, and thus a so-called “C-path” is constituted, while this transport path
32
is formed along the substantially vertical direction from the paper supply units
18
a
to
18
d
arranged along the horizontal direction. In this embodiment mode, since the process cartridge
64
is stored within the C-path, the layout of this image forming apparatus can be made compact. However, if the developer storage space connected to the developing unit
114
is arranged lower than the latent image writing position “P” in the normal design manner, such a dead space is produced under the ejection portion
16
. More specifically, in the case that a storage capacity of the developer is increased, since the space located lower than the latent image writing position “P” must be increased, a larger dead space is produced.
However, in this embodiment mode, the window portion
120
which constitutes the scanning optical path from the optical writing apparatus
58
is formed in the process cartridge
64
, and also, the developer paths
122
a
and
123
b
are formed on both sides of this window portion
120
, so that the first developer storage portion
116
a
can be arranged above the scanning optical path. As a result, the image forming apparatus can be made compact, while the sufficiently large developer storage capacity can be maintained.
In
FIGS. 9A
to
9
E, various sorts of modifications are illustrated with respect to the above-described second stirring/transporting member
130
. Similar to the above-described embodiment mode, a second stirring/transporting member
130
shown in
FIG. 9A
is similarly constituted by employing a shaft portion
132
, and two screw portions
134
a
and
134
b
which are formed from edge portions of this shaft portion
132
(as viewed in axial line direction thereof) toward a center portion thereof along mutually different directions. However, this second stirring/transporting member
130
owns such a different structural point that a pitch of each screw part of the screw portions
134
a
and
134
b
is continuously changed. The pitches of the screw portions
134
a
and
134
b
are gradually increased from the both edge portions thereof to the center portions thereof in order that the developer may be easily collected to the center parts thereof, and thus, the transport amounts of the developer along the axial direction can be made equal to each other.
As to a second stirring/transporting member
130
indicated in
FIG. 9B
, pitches of respective screw portions are changed in a stepwise manner in contrast to the above-explained second stirring/transporting member
130
of
FIG. 9A
in which the pitches of the respective screw portions are changed in the continuous manner. As to a third stirring/transporting member
130
shown in
FIG. 9C
, while flat plate portions
160
a
and
160
b
are employed instead of the screw portions, pitches of these flat plate portions
160
a
and
160
b
are changed in a continuous manner. As to a second stirring/transporting member
130
represented in
FIG. 9D
, the pitches of the flat plate portions
160
a
and
160
b
are changed in a stepwise manner.
A second stirring/transporting member
130
indicated in
FIG. 9E
is constituted by a wire line material formed in a crank shape. In the case that developer owns good fluidity, the developer may be uniformly transported due to the good fluidity of this developer by merely forming the wire line material in the crank shape and by merely stirring the developer.
It should be noted that the second stirring/transporting members
130
with employment of the above-described constructions may be driven in an intermittent manner so as to control the transport amount thereof. In order to intermittently drive these second stirring/transporting members
130
, for instance, a pulse motor may be employed irrespective of motors which are employed in other drive systems.
In the above-described embodiment modes, the one-component developing system is employed. The present invention is not limited to this one-component developing system, but may be applied to a two-component developing system. Also, in the above-explained embodiment mode, the developer image is directly transferred from the image carrier to the recording medium. However, the present invention is not limited to this transfer operation, but may be applied to another embodiment in which an intermediate transfer member may be interposed between the image carrier and the recording medium. Furthermore, in the above-described embodiment modes, the black/white image forming apparatus has been described. Apparently, the present invention may be applied to a color image forming apparatus.
As previously explained, in accordance with the present invention, since the developer storage portions are provided along the upper/lower portions by sandwiching therebetween the latent image writing position of the image carrier, the image forming apparatus can be made compact while the sufficiently large developer storage capacity can be maintained.
Claims
- 1. A process cartridge detachably mounted on a main body of an image forming apparatus comprising:an image carrier; and a developing apparatus having a developer storage space, for developing a latent image formed on the image carrier to produce a visible image; wherein: the developer storage space is segmented into a first developer storage portion and a second developer storage portion along upper/lower directions, while sandwiching therebetween a latent image writing position of the image carrier into which the latent image is written; and also the first developer storage portion is communicated to the second developer storage portion via a developer path.
- 2. A process cartridge according to claim 1, whereinthe developer path is formed at a peripheral portion of a window portion which constitutes an optical scanning path.
- 3. A process cartridge according to claim 2, whereinthe developer path is formed on both sides of the window portion.
- 4. A process cartridge according to claim 3, whereinthe first developer storage portion owns a first stirring/transporting member which stirs/transports the developer from a center of the first stirring/transporting member to both sides thereof.
- 5. A process cartridge according to claim 4, whereinthe second developer storage portion owns a second stirring/transporting member which stirs/transports the developer from both sides of the second stirring/transporting member to a center thereof.
- 6. A process cartridge according to claim 5, whereinthe second stirring/transporting member is driven in an intermittent manner.
- 7. An image forming apparatus, whereinthe image forming apparatus is comprised of the process cartridge recited in claim 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
P2002-261912 |
Sep 2002 |
JP |
|
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
6453135 |
Sameshima et al. |
Sep 2002 |
B1 |
Foreign Referenced Citations (1)
Number |
Date |
Country |
05-323694 |
Dec 1993 |
JP |