Note: Descriptions are shown in the official language in which they were submitted.
1
Description
Title of Invention: DRUM CARTRIDGE AND DEVELOPING
CARTRIDGE
Technical Field
[0001] The present disclosure relates to drum cartridge and developing
cartridge.
Background Art
[0002] Electro-photographic image forming apparatuses, such as laser printers
and LED
printers, have been developed. A developing cartridge is used in an image
forming
apparatus. The developing cartridge includes a developing roller for supplying
a
developer material. An existing image forming apparatus is described in, for
example, PTL 1.
[0003] The developing cartridge described in PTL 1 is mounted on a drum
cartridge. The
drum cartridge includes a photosensitive drum. When the developing cartridge
is
mounted on the drum cartridge, the photosensitive drum is brought into contact
with
the developing roller. Thereafter, the drum cartridge having the developing
cartridge
mounted therein is mounted in the image forming apparatus.
Citation List
Patent Literature
[0004] PTL 1: Japanese Patent Application Publication No. 2013-54058.
Summary of Invention
Technical Problem
[0005] The drum cartridge includes one member configured to press the
developing
cartridge toward the photosensitive drum. In addition, the drum cartridge may
include
another member configured to supply a developing electrode for the developing
roller with bias voltage. However, if one member configured to press the
developing
cartridge toward the photosensitive drum and another member configured to
supply
a developing electrode for the developing roller with bias voltage are
separately
provided, the number of parts in the drum cartridge increases.
[0006] Accordingly, the object of the present disclosure is to provide a
structure capable of
reducing the number of parts in a drum cartridge.
Solution to Problem
[0007] A first disclosure of the present application is characterized by a
drum cartridge that
enables a developing cartridge to be mountable thereon, including a
photosensitive
drum rotatable about a shaft extending in a first direction, and an
electrically
conductive movable member, when the developing cartridge is mounted on the
drum
7764323
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cartridge, the movable member applies pressure to a developing electrode
included in
the developing cartridge toward the photosensitive drum.
[0008] A second disclosure of the present application is characterized in
that, in the drum
cartridge according to the first disclosure, an electrically conductive
resilient member
configured to apply pressure to the movable member toward the photosensitive
drum.
[0009] A third disclosure of the present application is characterized in
that in the drum
cartridge according to the second disclosure, the resilient member is a
spring.
[0010] A fourth disclosure of the present application is characterized in
that in the drum
cartridge according to the third disclosure, the resilient member is a coil
spring.
[0011] A fifth disclosure of the present application is characterized in
that a developing
cartridge mountable on the drum cartridge according to any one of the first
disclosure
to the forth disclosure, including a developing roller including a developing
roller shaft
extending in the first direction, a casing capable of containing a developer
material,
and a developing electrode having a first end portion and a second end portion
located
farther away from the developing roller shaft than the first end portion, the
first end
portion configure to be electrically connected to the developing roller shaft,
the
movable member presses the second end portion of the developing electrode
toward
the photosensitive drum.
[0012] A sixth disclosure of the present application is characterized in
that in the developing
cartridge according to the fifth disclosure, the casing extends in a second
direction that
crosses the first direction, the developing roller is located at one end of
the casing in
the second direction, and the second end portion of the developing electrode
is farther
away in the second direction from the one end of the casing than the first end
portion is
from the one end of the casing.
[0013] A seventh disclosure of the present application is characterized in
that in the de-
veloping cartridge according to the fifth disclosure or the sixth disclosure,
the de-
veloping electrode is pivotable about a rotation axis extending in the first
direction
with respect to the first end portion.
[0014] An eighth disclosure of the present application is characterized in
that in the de-
veloping cartridge according to the seventh disclosure, the developing
electrode is
pivotable about the rotation axis between a first position and a second
position, the
casing has a first restricting surface that is in contact with the second end
portion of the
developing electrode when the developing electrode is located at the first
position and
a second restricting surface that is in contact with the second end portion of
the de-
veloping electrode when the developing electrode is located at the second
position.
[0015] A ninth disclosure of the present application is characterized in
that in the developing
cartridge according to the seventh disclosure, the second end portion of the
developing
electrode has a hole extending in the first direction, the casing includes a
casing shaft
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inserted into the hole, and a length of the hole is longer than a length of
the casing
shaft in a pivotal direction of the second end portion about the rotation
axis.
[0016] A tenth disclosure of the present application is characterized in
that in the developing
cartridge according to the ninth disclosure, the hole has a first inner side
surface and a
second inner side surface away from the first inner side surface in the
pivotal direction,
the casing shaft is in contact with the first inner side surface when the
developing
electrode is located at the first position, and the casing shaft is in contact
with the
second inner side surface when the developing electrode is located at the
second
position.
[0017] An eleventh disclosure of the present application is characterized
in that in the de-
veloping cartridge according to any one of the fifth disclosure to the tenth
disclosure,
the developing roller shaft is electrically conductive.
[0018] A twelfth disclosure of the present application is characterized in
that in the de-
veloping cartridge according to any one of the fifth disclosure to the
eleventh
disclosure, the developing electrode is electrically conductive.
[0019] A thirteenth disclosure of the present application is characterized
in that in the de-
veloping cartridge according to the twelfth disclosure, the developing
electrode is
made of a conductive resin.
[0020] A fourteenth disclosure of the present application is characterized
in that in the de-
veloping cartridge according to any one of the fifth disclosure thirteenth
disclosure to
thirteenth disclosure, the casing has a first outer surface located at one end
thereof in
the first direction, and the developing electrode extends along the first
outer surface
between the first end portion and the second end portion.
[0021] A fifteenth disclosure of the present application is characterized
by the developing
cartridge according to the fourteenth disclosure, the developing electrode
serves as a
first bearing that rotatably supports the developing roller shaft.
[0022] A sixteenth disclosure of the present application is characterized
in that in the de-
veloping cartridge according to any one of the fifth disclosure to the
fourteenth dis-
closures, the developing electrode has a shaft hole that extends in the first
direction and
that has a cylindrical inner peripheral surface, and the developing roller
shaft is
inserted into the shaft hole.
[0023] A seventeenth disclosure of the present application is characterized
in that in the de-
veloping cartridge according to the fifteenth disclosure, the casing further
has a second
outer surface located at the other end thereof in the first direction, and the
developing
cartridge further includes a second bearing extending between a third end
portion and a
fourth end portion located farther away from the developing roller shaft than
the third
end portion is from the developing roller shaft, and the second bearing is
pivotable
about the rotation axis with respect to the casing.
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[0024] An eighteenth disclosure of the present application is characterized
in that in the
developer cartridge according to any one of fifth disclosure or the
seventeenth
disclosure, when the developing cartridge is mounted on the drum cartridge,
the first
end portion of the developing electrode is in contact with one portion of the
drum
cartridge.
[0025] A nineteenth disclosure of the present application is characterized
in that in the de-
veloping cartridge according to the eighteenth disclosure, when the developing
cartridge is mounted on the drum cartridge, the second end portion of the
developing
electrode is in contact with an other portion of the drum cartridge.
Advantageous Effects of Invention
[0026] According to the first to nineteenth disclosure disclosures of the
present application,
a bias voltage can be supplied the developing electrode of the developing
cartridge via
the movable member of the drum cartridge. As a result, the number of parts of
the
drum cartridge can be reduced as compared with the case where an electrically
conductive member for supplying the developing electrode with the bias voltage
is
provided separately from the movable member.
Brief Description of Drawings
[0027] [fig. l]Fig. 1 is a perspective view of a developing cartridge and a
drum cartridge.
[fig.21Fig. 2 is a perspective view illustrating the developing cartridge
mounted on the
drum cartridge.
[fig.3]Fig. 3 is an exploded perspective view of the developing cartridge.
[fig.4]Fig. 4 is an exploded perspective view of a portion of the developing
cartridge in
the vicinity of a first outer surface of a casing.
[fig.5]Fig. 5 is an exploded perspective view of a portion of the developing
cartridge in
the vicinity of a second outer surface of the casing.
[fig.6]Fig. 6 is an exploded front view of the developing cartridge in the
vicinity of the
first outer surface of the casing.
[fig.7]Fig. 7 is a view illustrating the pivotal movement of a first bearing.
[fig.8]Fig. 8 is a cross-sectional view of the developing cartridge and the
drum
cartridge when the developing cartridge is mounted on the drum cartridge.
[fig.9]Fig. 9 is a cross-sectional view of the developing cartridge and the
drum
cartridge when the developing cartridge is mounted on the drum cartridge.
[fig.10]Fig. 10 is a cross-sectional view of the developing cartridge and the
drum
cartridge when the developing cartridge is mounted on the drum cartridge.
[fig.11]Fig. 11 is a cross-sectional view of the developing cartridge and the
drum
cartridge when the developing cartridge is mounted on the drum cartridge.
[fig.12]Fig. 12 is a side view of the developing cartridge and the drum
cartridge after
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the developing cartridge is mounted on the drum cartridge.
[fig.13]Fig. 13 is a side view of the drum cartridge.
[fig.14]Fig. 14 is a cross-sectional view of the developing cartridge and the
drum
cartridge during a separating operation.
[fig.15]Fig. 15 is a side view of a drum cartridge according to a first
modification.
[fig.16]Fig. 16 is a side view of a first bearing according to a second
modification.
Description of Embodiments
[0028] Embodiments of the present disclosure are described below with
reference to the ac-
companying drawings.
[0029] Hereinafter, the direction in which a developing roller 30 of a
developing cartridge 1
extends is referred to as a "first direction". In addition, the direction
between which an
agitator 20 and the developing roller 30 of the developing cartridge 1 are
arranged is
referred to as a "second direction". The first direction and the second
direction cross
(preferably, orthogonally cross) each other.
[0030] <1. Overview of Developer Cartridge and Drum Cartridge>
Fig. 1 is a perspective view of the developing cartridge 1 and the drum
cartridge 2.
Fig. 2 is a perspective view of the developing cartridge 1 mounted on the drum
cartridge 2. The developing cartridge 1 and the drum cartridge 2 are used in
an electro-
photographic image forming apparatus. An example of the image forming
apparatus is
a laser printer or an LED printer.
[0031] As illustrated in Figs. 1 and 2, the developing cartridge 1 is used
together with the
drum cartridge 2. The developing cartridge 1 is mountable on the drum
cartridge 2.
The developing cartridge 1 is mounted on the drum cartridge 2 and, thereafter,
is
mounted in the image forming apparatus. The image forming apparatus allows,
for
example, four developing cartridges 1 to be mounted therein. The four
developing
cartridges 1 contain developer materials (for example, toner) of different
colors (for
example, cyan, magenta, yellow, and black). The image forming apparatus forms
an
image on a recording surface of print paper by using the developer materials
supplied
from the developing cartridges 1. Note that the number of developing
cartridges 1
mountable in the image forming apparatus may be one or more and so, in
addition to
being four, may be one to three, or five or more.
[0032] <2. Information about Developing Cartridge>
Fig. 3 is an exploded perspective view of the developing cartridge 1. Fig. 4
is a view
of the developing cartridge 1, in particular an exploded perspective view, in
the
vicinity of a first outer surface 11 of a casing 10. Fig. 5 is a view of the
developing
cartridge 1, in particular an exploded perspective view in the vicinity of a
second outer
surface 12 of the casing 10. As illustrated in Figs. 1 to 5, the developing
cartridge 1
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includes the casing 10, the agitator 20, the developing roller 30, a supply
roller 40, a
gear unit 50, a first bearing 60, and a second bearing 70. The first bearing
60 is also a
developing electrode 60.
[0033] The casing 10 is a casing capable of containing a developer
material. The casing 10
has the first outer surface 11 and the second outer surface 12. The first
outer surface 11
is located at one end of the casing 10 in the first direction. The second
outer surface 12
is located at the other end of the casing 10 in the first direction. The first
outer surface
11 and the second outer surface 12 are separated from each other in the first
direction.
The casing 10 extends in the first direction between the first outer surface
11 and the
second outer surface 12. In addition, the casing 10 extends in the second
direction.
[0034] The casing 10 has an accommodation chamber 13 provided thereinside.
The
developer material is stored in the accommodation chamber 13. In addition, the
casing
has an opening 14. The opening 14 is located at one end 10a of the casing 10
in the
second direction. The outside of the casing 10, in other words the external
space, and
the accommodation chamber 13 of the casing 10 communicate with each other
through
the opening 14. Note that the casing 10 may have a handle on the outer surface
at the
other end 10b in the second direction.
[0035] The agitator 20 includes an agitator shaft 21 and a blade 22. The
agitator shaft 21
extends in the first direction. The blade 22 extends or expands from the
agitator shaft
21 toward the inner surface of the casing 10. The blade 22 and part of the
agitator shaft
21 are disposed in the accommodation chamber 13 of the casing 10. An agitator
gear
51 included in the gear unit 50 is attached to one end of the agitator shaft
21 in the first
direction. The agitator shaft 21 is fixed to the agitator gear 51 so as not to
rotate
relative to the agitator gear. When the agitator gear 51 rotates, the agitator
shaft 21 and
the blade 22 rotate about the rotation axis extending in the first direction.
Thus, the
developer material is agitated in the accommodation chamber 13 by the blade 22
that is
rotating.
[0036] The developing roller 30 is a roller that can rotate about a
rotation axis (a first axis)
Al extending in the first direction. The developing roller 30 is located in
the opening
14 of the casing 10. That is, the developing roller 30 is located at the one
end of the
casing 10 in the second direction. The developing roller 30 includes a
developing roller
main body 31 and a developing roller shaft 32. The developing roller main body
31 is a
cylindrical member extending in the first direction. As the material used for
the de-
veloping roller main body 31, rubber having resilience is used, for example.
The de-
veloping roller shaft 32 is a cylindrical member that extends in the first
direction and
passes completely through the developing roller main body 31. The developing
roller
shaft 32 is electrically conductive. For the material of the developing roller
shaft 32,
metal or resin having electrical conductivity is used.
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[0037] The developing roller main body 31 is fixed to the developing roller
shaft 32 so as
not to rotate relative to the developing roller shaft 32. Furthermore, a
developing roller
gear 52 included in the gear unit 50 is attached to an end portion of the
developing
roller shaft 32 in the first direction. The developing roller shaft 32 is
fixed to the de-
veloping roller gear 52 so as not to rotate relative to the developing roller
gear 52. Ac-
cordingly, when the developing roller gear 52 rotates, the developing roller
shaft 32
rotates, and the developing roller main body 31 also rotates together with the
de-
veloping roller shaft 32.
[0038] Note that the developing roller shaft 32 need not pass completely
through the de-
veloping roller main body 31 in the first direction. For example, the
developing roller
shaft 32 may comprise two respective parts that extend in the first direction
from both
ends of the developing roller main body 31 in the first direction.
[0039] The supply roller 40 is a roller that is rotatable about a rotation
axis (a second axis)
extending in the first direction. The supply roller 40 is located between the
agitator 20
and the developing roller 30. The supply roller 40 includes a supply roller
main body
41 and a supply roller shaft 42. The supply roller main body 41 is a
cylindrical member
extending in the first direction. As the material used for the supply roller
main body
41, rubber having resilience is used, for example. The supply roller shaft 42
is a
columnar member extending in the first direction so as to pass completely
through the
supply roller main body 41.
[0040] The supply roller main body 41 is fixed to the supply roller shaft
42 so as not to
rotate relative to the supply roller shaft 42. In addition, a supply roller
gear 53 included
in the gear unit 50 is attached to an end of the supply roller shaft 42 in the
first
direction. The supply roller shaft 42 is fixed to the supply roller gear 53 so
as not to
rotate relative to the supply roller gear. Consequently, if the supply roller
gear 53
rotates, the supply roller shaft 42 also rotates and, thus, the supply roller
main body 41
also rotates together with the supply roller shaft 42.
[0041] Note that the supply roller shaft 42 need not pass completely
through the supply
roller main body 41 in the first direction. For example, the supply roller
shaft 42 may
comprise two respective parts that extend in the first direction from both
ends of the
supply roller main body 41 in the first direction.
[0042] When the developing cartridge 1 receives the driving force, the
developer material is
supplied from the accommodation chamber 13 in the casing 10 to the outer
peripheral
surface of the developing roller 30 via the supply roller 40. At this time,
the developer
material is triboelectrically charged between the supply roller 40 and the
developing
roller 30. In addition, a bias voltage is applied to the developing roller
shaft 32 of the
developing roller 30. For this reason, the developer material is attracted to
the outer pe-
ripheral surface of the developing roller main body 31 by the electrostatic
force
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between the developing roller shaft 32 and the developer material.
[0043] Furthermore, the developing cartridge 1 includes a layer thickness
regulation blade
(not illustrated). The layer thickness regulation blade shapes the developer
material
supplied onto the outer peripheral surface of the developing roller main body
31 into a
predetermined thickness. Thereafter, the developer material on the outer
peripheral
surface of the developing roller main body 31 is supplied to a photosensitive
drum 92
(described below) of the drum cartridge 2. At this time, the developer
material moves
from the developing roller main body 31 onto the photosensitive drum 92 in ac-
cordance with an electrostatic latent image formed on the outer peripheral
surface of
the photosensitive drum 92. In this manner, the electrostatic latent image is
visualized
on the outer peripheral surface of the photosensitive drum 92.
[0044] The gear unit 50 is located on the second outer surface 12 of the
casing 10. As il-
lustrated in Fig. 5, the gear unit 50 includes the above-described agitator
gear 51, de-
veloping roller gear 52, and supply roller gear 53, a plurality of idle gears
56, a
coupling 54, and a gear cover 55. The gear cover 55 and the cover 10 together
constitute the overall casing of the developing cartridge 1 together with the
casing 10.
The gear cover 55 is fixed to the second outer surface 12 of the casing 10 by,
for
example, screwing. At least some of the plurality of gears are located between
the
second outer surface 12 and the gear cover 55.
[0045] The coupling 54 has an engagement portion 541 recessed in the first
direction. The
engagement portion 541 is exposed through the gear cover 55. When the
developing
cartridge 1 mounted on the drum cartridge 2 is mounted in an image forming
apparatus
having a drive shaft, the drive shaft of the image forming apparatus is
connected to the
engagement portion 541 of the coupling 54. Thus, the rotation of the drive
shaft of the
image forming apparatus is transmitted to the agitator gear 51, the plurality
of idle
gears 56, the developing roller gear 52, and the supply roller gear 53 via the
coupling
54.
[0046] The plurality of gears included in the gear unit 50 may transmit the
rotational force
by meshing of teeth or may transmit the rotational force by friction.
[0047] Fig. 6 is a view of the developing cartridge 1 in particular an
exploded front view in
the vicinity of the first outer surface 11 of the casing 10. As illustrated in
Figs. 1, 4 and
6, the first bearing 60 is located on the first outer surface 11 of the casing
10. The first
bearing 60 rotatably supports one end of the developing roller shaft 32 in the
first
direction.
[0048] The first bearing 60 has a first end portion 61 and a second end
portion 62. The
second end portion 62 is farther away from the developing roller shaft 32 than
the first
end portion 61 is to the developing roller shaft 32. In addition, the second
end portion
62 is farther away in the second direction from the one end 10a of the casing
10 in the
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second direction than the first end portion 61 is to the one end 10a of the
casing 10 in
the second direction. The first bearing 60 extends along the first outer
surface 11 of the
casing 10 between the first end portion 61 and the second end portion 62.
[0049] The first bearing 60 includes a first arm 63 and a second arm 64.
The second arm 64
is farther away from the developing roller shaft 32 than the first arm 63. In
addition,
the second arm 64 is farther away from the one end 10a in the second direction
of the
casing 10 than the first arm 63 is to the one end 10a in the second direction.
The first
arm 63 has the first end portion 61 described above. The second arm 64 has the
second
end portion 62 described above. The first arm 63 extends along the first outer
surface
11 of the casing 10, for example, linearly. The second arm 64 extends along
the first
outer surface 11 of the casing 10, for example, linearly. Note that the first
arm 63 is at
an angle to the second arm 64. The angle formed by the first arm 63 and the
second
arm 64 is an obtuse angle.
[0050] According to the present embodiment, the first arm 63 and the second
arm 64 are in-
tegrally formed. However, the first arm 63 and the second arm 64 may be
separate
parts. In this case, the first arm 63 and the second arm 64 can be fixed to
each other.
[0051] The first bearing 60 has a first shaft hole 65. The first shaft hole
65 extends in the
first direction in the first end portion 61 of the first bearing 60. The first
shaft hole 65
may be a through-hole passing through the first end portion 61 in the first
direction.
Alternatively, the first shaft hole 65 may be a hole that does not pass
through the first
end portion 61. The first shaft hole 65 has a cylindrical inner peripheral
surface. One
end of the developing roller shaft 32 in the first direction is inserted into
the first shaft
hole 65. Thus, the one end of the developing roller shaft 32 in the first
direction is
supported so as to be rotatable about a rotation axis (a first axis) Al
extending in the
first direction. In addition, the first bearing 60 is pivotable about the
rotation axis Al
with respect to the casing 10. More specifically, the second end portion 62 is
pivotable
about the rotation axis Al with respect to the first end portion 61.
[0052] The first bearing 60 serves as an electrically conductive member
which, because it
provides electrical connection to the developing roller shaft 32, is described
herein as a
developing electrode. The first bearing 60 is made of, for example, a
conductive resin.
However, the first bearing 60 may be made of metal. The first end portion 61
of the
first bearing 60 is in contact with the one end of the developing roller shaft
32 in the
first direction. Consequently, the first end portion 61 of the first bearing
60 is elec-
trically connected to the developing roller shaft 32. Alternatively, the first
bearing 60
may be a pivotable member. The pivotable member may be configured to
electrically
connected to the developing roller shaft 32. Preferably, the first pivotable
member may
be a pivotable lever.
[0053] As illustrated in Fig. 4, the casing 10 has a casing recess 15. The
inner surface of the
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casing recess 15 includes a first restricting surface 151 and a second
restricting surface
152. The first restricting surface 151 and the second restricting surface 152
are
separated from each other in the rotational direction of the second end
portion 62 about
the rotation axis Al. In addition, as illustrated in Fig. 6, the first bearing
60 has a
protrusion, for example having a rod-like shape, described herein as a bearing
shaft 66.
The bearing shaft 66 protrudes from the second end portion 62 of the first
bearing 60
toward the other side in the first direction. The bearing shaft 66 is inserted
into the
casing recess 15.
[0054] Fig. 7 illustrates how the first bearing 60 pivots. The first
bearing 60 is pivotable
about the rotation axis Al between a first position illustrated in the upper
section of
Fig. 7 and a second position illustrated in the lower section of Fig. 7. When
the first
bearing 60 is located at the first position, the bearing shaft 66 is in
contact with the first
restricting surface 151. In contrast, when the first bearing 60 is located at
the second
position, the bearing shaft 66 is in contact with the second restricting
surface 152. In
this manner, the pivot range of the first bearing 60 about the rotation axis
Al is re-
stricted.
[0055] In addition, the first bearing 60 has a first hole 67. The first
hole 67 extends in the
second direction between the first end portion 61 and the second end portion
62. Fur-
thermore, the first hole 67 passes completely through the first bearing 60 in
a pivotal
direction about the rotation axis Al. However, the first hole 67 need not pass
completely through the first bearing 60. When the developing cartridge 1 is
mounted
on the drum cartridge 2, the first hole 67 allows a first lever 97 (described
below) of
the drum cartridge 2 to be inserted thereinto.
[0056] As illustrated in Fig. 3, the second bearing 70 is located on the
second outer surface
12 of the casing 10. More specifically, the second bearing 70 is located on
the outer
surface of the gear cover 55. The first bearing 60 and the second bearing 70
are located
so as to overlap each other, as viewed in the first direction. The second
bearing 70
rotatably supports the other end of the developing roller shaft 32 in the
first direction.
The second bearing 70 has a third end portion 71 and a fourth end portion 72.
The
fourth end portion 72 is farther away from the developing roller shaft 32 than
the third
end portion 71. In addition, the fourth end portion 72 is farther away in the
second
direction from the one end 10a of the casing 10 in the second direction than
the third
end portion 71 is to the one end 10a of the casing 10 in the second direction.
The
second bearing 70 extends along the second outer surface 12 of the casing 10
between
the third end portion 71 and the fourth end portion 72.
[0057] The second bearing 70 includes a third arm 73 and a fourth arm 74.
The fourth arm
74 is farther away from the developing roller shaft 32 than the third arm 73.
In
addition, the fourth arm 74 is farther away in the second direction from the
one end
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10a of the casing 10 in the second direction than the third arm 73 is to the
one end 10a
of the casing 10 in the second direction. The third arm 73 has the third end
portion 71
described above. The fourth arm 74 has the fourth end portion 72 described
above. The
third arm 73 extends along the second outer surface 12 of the casing 10, for
example,
linearly. The fourth arm 74 extends along the second outer surface 12 of the
casing 10,
for example, linearly. However, the third arm 73 is at an angle to the fourth
arm 74.
The angle formed by the third arm 73 and the fourth arm 74 is an obtuse angle.
[0058] According to the present embodiment, the third arm 73 and the fourth
arm 74 are in-
tegrally formed. However, the third arm 73 and the fourth arm 74 may be
separate
parts. In this case, it is only required that the third arm 73 and the fourth
arm 74 are
fixed to each other.
[0059] The second bearing 70 has a second shaft hole 75. The second shaft
hole 75 extends
in the first direction in the third end portion 71 of the second bearing 70.
The second
shaft hole 75 may be a through-hole passing through the third end portion 71
in the
first direction. Alternatively, the second shaft hole 75 may be a hole that
does not pass
through the third end portion 71. The second shaft hole 75 has a cylindrical
inner cir-
cumferential surface. The other end of the developing roller shaft 32 in the
first
direction is inserted into the second shaft hole 75. In this manner, the other
end of the
developing roller shaft 32 in the first direction is supported in a rotatable
manner about
a rotation axis (a first axis) Al extending in the first direction. In
addition, the second
bearing 70 is also pivotable about the rotation axis Al with respect to the
casing 10.
More specifically, the fourth end portion 72 is pivotable about the rotation
axis Al
with respect to the third end portion 71.
[0060] As illustrated in Fig. 5, the gear cover 55 has a gear cover
projection 550. The gear
cover projection 550 protrudes from the gear cover 55 toward the other side in
the first
direction. In addition, the second bearing 70 has a hook portion 76. The hook
portion
76 protrudes from the outer surface of the second bearing 70 in the rotational
direction
of the fourth end portion 72 about the rotation axis Al. Furthermore, the
second
bearing 70 has a third restricting surface 761 located at the base end of the
hook
portion 76 and a fourth restricting surface 762 located at the top end of the
hook
portion 76. The third restricting surface 761 and the fourth restricting
surface 762 are
separated from each other in the pivotal direction of the fourth end portion
72 about the
rotation axis Al.
[0061] The second bearing 70 is pivotable about the rotation axis Al
between the third
position and the fourth position. When the second bearing 70 is located at the
third
position, the third restricting surface 761 of the second bearing 70 is in
contact with the
gear cover projection 550. In contrast, when the second bearing 70 is located
at the
fourth position, the fourth restricting surface 762 of the second bearing 70
is in contact
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with the gear cover projection 550. In this manner, the rotation range of the
second
bearing 70 is restricted.
[0062] In addition, the second bearing 70 has a third hole 77. The third
hole 77 extends in
the second direction between the third end portion 71 and the fourth end
portion 72.
Furthermore, the third hole 77 passes completely through the second bearing 70
in a
pivotal direction about the rotation axis Al. However, the third hole 77 need
not pass
completely through the second bearing 70. When the developing cartridge 1 is
mounted on the drum cartridge 2, the third hole 77 allows a second lever
(described
below) of the drum cartridge 2 to be inserted thereinto. The first hole 67 of
the first
bearing 60 and the third hole 77 of the second bearing 70 are located so as to
overlap
each other, as viewed in the first direction.
[0063] <3. Structure of Drum Cartridge>
As illustrated in Figs. 1 and 2, the drum cartridge 2 includes the drum frame
91 and
the photosensitive drum 92. The developing cartridge 1 is mounted on the drum
frame
91. The photosensitive drum 92 is a cylindrical drum which is rotatable about
a
rotation axis extending in the first direction. The outer peripheral surface
of the photo-
sensitive drum 92 is coated with a photosensitive material. The photosensitive
drum 92
is located at one end of the drum frame 91 in the second direction. When the
de-
veloping cartridge 1 is mounted on the drum frame 91, the outer peripheral
surface of
the developing roller 30 is in contact with the outer peripheral surface of
the photo-
sensitive drum 92.
[0064] Figs. 8 to 11 are cross-sectional views of the developing cartridge
1 and the drum
cartridge 2 when the developing cartridge 1 is mounted on the drum cartridge
2. Figs, 8
to 11 are cross-sectional views of the developing cartridge 1 and the drum
cartridge 2
taken along a break line S - S of Fig. 6. As illustrated in Figs. 8 to 11, the
drum
cartridge 2 has a first guide surface 93 and a second guide surface 94. The
first guide
surface 93 and the second guide surface 94 are located at one end of the drum
frame 91
in the first direction. In addition, the first guide surface 93 and the second
guide
surface 94 are separated in the rotational direction about the rotation axis
of the photo-
sensitive drum 92. Note that the drum cartridge 2 further has a third guide
surface (not
illustrated) and a fourth guide surface (not illustrated) that are similar to
the first guide
surface 93 and the second guide surface 94, respectively, at the other end of
the drum
frame 91 in the first direction,
[0065] Furthermore, as illustrated in Figs. 8 to 11, the drum cartridge 2
includes a first
movable member 95 and a first coil spring 96. The first movable member 95 and
the
first coil spring 96 are electrically conductive. The first movable member 95
is made
of, for example, a conductive resin. The first coil spring 96 is made of, for
example,
metal. The first movable member 95 and the first coil spring 96 are located at
one end
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of the drum frame 91 in the first direction. The first coil spring 96 is a
resilient member
that can expand and contract in the second direction. One end of the first
coil spring 96
in the second direction is connected to the first movable member 95. The other
end of
the first coil spring 96 in the second direction is connected to the drum
frame 91. With
the developing cartridge 1 mounted on the drum cartridge 2, the first movable
member
95 applies pressure to the second end portion 62 of the first bearing 60
toward the pho-
tosensitive drum 92 by the resilience force of the first coil spring 96.
[0066] In addition, the drum cartridge 2 includes a second movable member
(not illustrated)
and a second coil spring (not illustrated). The second movable member and the
second
coil spring are located at the other end of the drum frame 91 in the first
direction. With
the developing cartridge 1 mounted on the drum cartridge 2, the second movable
member applies a pressure to the fourth end portion 72 of the second bearing
70
toward the photosensitive drum 92 by the resilience force of the second coil
spring.
[0067] Note that instead of using the first coil spring 96 and the second
coil spring, other
types of resilient members may be used for the drum cartridge 2. For example,
the
drum cartridge 2 may be provided with a spring other than a coil spring (e.g.,
a torsion
spring or a leaf spring), rubber, or the like) as the resilient member.
[0068] In addition, as illustrated in Figs. 8 to 11, the drum cartridge 2
includes a first lever
97. The first lever 97 is located at one end of the drum frame 91 in the first
direction.
The first lever 97 is located between the first movable member 95 and the
photo-
sensitive drum 92. The first lever 97 is pivotable about a rotation shaft
extending in the
first direction. When the developing cartridge 1 is mounted on the drum
cartridge 2,
the first lever 97 is inserted into, and so located in, the first hole 67 of
the first bearing
60.
[0069] In addition, the drum cartridge 2 includes a second lever (not
illustrated). The second
lever is located at the other end of the drum frame 91 in the first direction.
The second
lever is located between the second movable member and the photosensitive drum
92.
The second lever is pivotable about a rotation shaft extending in the first
direction.
When the developing cartridge 1 is mounted on the drum cartridge 2, the second
lever
is inserted into, and so located in, the third hole 77 of the second bearing
70.
[0070] <4. Information about Operation to Mount Development Cartridge>
As illustrated in Figs. 8 to 11, when the developing cartridge 1 is mounted on
the
drum cartridge 2, the developing cartridge 1 is moved relative to the drum
cartridge 2
so that the developing roller 30 moves close to the photosensitive drum 92. At
this
time, as illustrated in Figs. 9 to 11, the first end portion 61 of the first
bearing 60 is
brought into contact with the second guide surface 94 and moves along the
second
guide surface 94. Accordingly, the first bearing 60 pivots about the rotation
axis Al
from the first position to the second position. Similarly, the third end
portion 71 of the
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second bearing 70 is brought into contact with the fourth guide surface and
moves
along the fourth guide surface. Accordingly, the second bearing 70 pivots
about the
rotation axis Al from the third position to the fourth position.
[0071] As described above, when the developing cartridge 1 is mounted on
the drum
cartridge 2, the first bearing 60 and the second bearing 70 pivot about the
rotation axis
Al of the developing roller 30. As a result, without rotating the casing 10
with respect
to the drum frame 91, the first bearing 60 can be placed between the
photosensitive
drum 92 and the first movable member 95. In addition, the second bearing 70
can be
placed between the photosensitive drum 92 and the second movable member. Con-
sequently, a user of the cartridges and the image forming apparatus can move
the de-
veloping roller 30 close to the photosensitive drum 92 without performing the
operation to rotate the casing 10.
[0072] With the first bearing 60 placed between the photosensitive drum 92
and the first
movable member 95, the first movable member 95 is in contact with the second
end
portion 62 of the first bearing 60. At this time, the first movable member 95
applies
pressure to the second end portion 62 of the first bearing 60 toward the
photosensitive
drum 92 by the resilience force of the first coil spring 96. Then, as
illustrated in Fig.
11, the first end portion 61 of the first bearing 60 is brought into contact
with the first
guide surface 93, and the second end portion 62 of the first bearing 60 is
brought into
contact with the second guide surface 94. In this manner, the position of the
first
bearing 60 relative to the drum frame 91 is fixed.
[0073] Similarly, the second movable member applies pressure to the fourth
end portion 72
of the second bearing 70 toward the photosensitive drum 92. At this time, the
third end
portion 71 of the second bearing 70 is brought into contact with the third
guide surface,
and the fourth end portion 72 of the second bearing 70 is brought into contact
with the
fourth guide surface. In this manner, the position of the second bearing 70
relative to
the drum frame 91 is fixed.
[0074] Furthermore, the first movable member 95 applies pressure to the
first bearing 60
with the positions of the first bearing 60 and the second bearing 70 relative
to the drum
frame 91 fixed. In addition, the second movable member applies pressure to the
second
bearing 70. Thus, the outer peripheral surface of the developing roller 30 is
brought
into contact with the outer peripheral surface of the photosensitive drum 92.
In this
manner, the developing roller 30 is urged against the photosensitive drum 92.
[0075] As described above, according to the present embodiment, the first
bearing 60 has
the first end portion 61 and the second end portion 62, and the second end
portion 62 is
pivotable with respect to the first end portion 61. In addition, the second
bearing 70 has
the third end portion 71 and the fourth end portion 72, and the fourth end
portion 72 is
pivotable with respect to the third end portion 71. Consequently, the
positioning of the
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developing roller 30 relative to the photosensitive drum 92 can be achieved by
using
the first end portion 61 and the second end portion 62 of the first bearing 60
and the
third end portion 71 and the fourth end portion 72 of the second bearing 70.
[0076] Furthermore, according to the present embodiment, when the
developing cartridge 1
is being mounted on the drum cartridge 2, the first bearing 60 and the second
bearing
70 pivot about the rotation axis Al. In addition, when the developing
cartridge 1 is
being removed from the drum cartridge 2, the first bearing 60 and the second
bearing
70 pivot about the rotation axis Al in the same manner. For this reason, the
developing
cartridge 1 can be smoothly mounted on or removed from the drum cartridge 2 by
causing the first bearing 60 and the second bearing 70 to pivot without
rotating the
casing 10.
[0077] <5. Information about Supply of Voltage>
Fig. 12 is a side view of the developing cartridge 1 and the drum cartridge 2
with the
developing cartridge 1 mounted on the drum cartridge 2. Note that in Fig. 12,
the drum
frame 91 is denoted by a two-dot chain line.
[0078] The first movable member 95 and the first coil spring 96 are
electrically conductive.
The first movable member 95 is made of, for example, a conductive resin. The
first
coil spring 96 is made of, for example, metal. In addition, as illustrated in
Fig. 12, the
drum cartridge 2 includes an electrode terminal 98 that is in electrical
contact with the
first coil spring 96. As illustrated in Figs. 1 and 2, the electrode terminal
98 is exposed
on the outer surface of the drum frame 91. Furthermore, as described above,
the de-
veloping roller shaft 32 and the first bearing 60 are electrically conductive.
For this
reason, when the developing cartridge 1 is mounted on the drum cartridge 2
and, thus,
the first movable member 95 is brought into contact with the first bearing 60,
the
electrode terminal 98, the first coil spring 96, the first movable member 95,
the first
bearing 60, and the developing roller shaft 32 are electrically connected to
one another.
[0079] When the developing cartridge 1 mounted on the drum cartridge 2 is
mounted in the
image forming apparatus, the electrode terminal of the image forming apparatus
is in
contact with the electrode terminal 98 of the drum cartridge 2. Thus, a bias
voltage is
supplied from the image forming apparatus to the developing roller shaft 32
via the
electrode terminal 98, the first coil spring 96, the first movable member 95,
and the
first bearing 60. As a result, the developer material is attracted to the
outer peripheral
surface of the developing roller main body 31 by the electrostatic force
generated by
the bias voltage.
[0080] As described above, according to the present embodiment, the bias
voltage is
supplied to the first bearing 60 of the developing cartridge 1 via the first
movable
member 95 of the drum cartridge 2. In this way, the number of parts of the
drum
cartridge 2 can be reduced as compared with the case where a conductive part
for
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supplying a voltage to the first bearing 60 is provided separately from the
first movable
member 95. Therefore, the size of the drum cartridge 2 can be reduced.
[0081] In addition, the first bearing 60 according to the present
embodiment has (1) the ca-
pability of serving as a bearing for rotatably supporting the developing
roller shaft 32
and (2) the capability of serving as a positioning member that determines the
position
of the developing roller 30 relative to the photosensitive drum 92 when the
developing
cartridge 1 is mounted on the drum cartridge 2 and (3) the capability of
serving as a de-
veloping electrode for supplying a bias voltage to the developing roller shaft
32. For
this reason, the number of parts in the developing cartridge 1 can be reduced
as
compared with the case where these capabilities are provided by using
different
members. In addition, the size of the developing cartridge 1 can be reduced.
[0082] <6. Information about Separating Operation>
After the developing cartridge 1 mounted on the drum cartridge 2 is mounted in
the
image forming apparatus, the developing cartridge 1 can perform a separating
operation by the driving force supplied from the image forming apparatus. As
used
herein, the term "separating operation" refers to an operation to temporarily
separate
the developing roller 30 from the photosensitive drum 92. For example, when
monochrome printing is performed in the image forming apparatus, the
developing
cartridges 1 of colors other than black perform the separating operation. Note
that the
developing cartridge 1 of black color may perform the separating operation.
[0083] As illustrated in Fig. 11, when the developing cartridge 1 is
mounted on the drum
cartridge 2, the developing cartridge 1 is disposed at a contact position at
which the de-
veloping roller 30 is in contact with the photosensitive drum 92. At this
time, the first
lever 97 of the drum cartridge 2 is inserted into the first hole 67 of the
first bearing 60.
In addition, a second lever (not illustrated) of the drum cartridge 2 is
inserted into the
third hole 77 of the second bearing 70.
[0084] Fig. 13 is a side view of the drum cartridge 2. In Fig. 13, the drum
frame 91 is
denoted by a two-dot chain line. As illustrated in Fig. 13, the drum cartridge
2 includes
a first cam 99. The first cam 99 is located between the photosensitive drum 92
and the
first lever 97 in the second direction. In addition, the first cam 99 is
located between
each of the above-described first guide surface 93 and second guide surface 94
and the
drum frame 91 in the first direction. When the separation operation is
performed, the
first cam 99 pivots about a rotation shaft extending in the first direction by
the driving
force supplied from the image forming apparatus. Thus, a projection 991 of the
first
cam 99 presses a projection 971 of the first lever 97. As a result, the first
lever 97
pivots about the rotation axis extending in the first direction, from a
position indicated
by the solid line to a position indicated by a two-dot chain line illustrated
in Fig. 13. In
addition, the drum cartridge 2 includes a second cam similar to the first cam
99 in
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order to cause the second lever to pivot.
[0085] Fig. 14 is a cross-sectional view of the developing cartridge 1 and
the drum cartridge
2 at the time of the separating operation. Fig. 14 is a cross-sectional view
of the de-
veloping cartridge 1 and the drum cartridge 2 taken along a broken line S - S
in Fig. 6.
When the first lever 97 is rotated by the first cam 99, the first lever 97
presses an inner
surface 670 of the first hole 67 of the first bearing 60. More specifically,
the first lever
97 presses the second end portion 62 of the first bearing 60 in a direction
away from
the photosensitive drum 92 against the pressing force of the first coil spring
96. In
addition, when the second lever is caused to pivot by the second cam, the
second lever
presses the inner surface of the third hole 77 of the second bearing 70. More
specifically, the second lever presses the fourth end portion 72 of the second
bearing
70 in a direction away from the photosensitive drum 92 against the pressing
force of
the second coil spring.
[0086] Thus, the casing 10 and the developing roller 30 move in the
direction away from the
photosensitive drum 92 together with the first bearing 60 and the second
bearing 70.
As a result, the outer peripheral surface of the developing roller 30 is
separated from
the outer peripheral surface of the photosensitive drum 92. That is, the
developing
cartridge 1 moves from the above-described contact position to the separated
position
with respect to the drum cartridge 2.
[0087] As described above, according to the present embodiment, the
developing cartridge 1
can be moved from the contact position to the separated position by pressing
the first
bearing 60 and the second bearing 70. For this reason, the number of parts of
the de-
veloping cartridge 1 can be reduced as compared with the case where a member
that
receives a pressing force at the time of the separation operation is provided
separately
from the first bearing 60 and the second bearing 70. Consequently, the size of
the de-
veloping cartridge 1 can be reduced more.
[0088] In addition, the first bearing 60 is pivotable about the rotation
axis Al. Therefore, the
first lever 97 can press the inner surface 670 of the first hole 67 of the
first bearing 60
in an optimum direction without rotating the casing 10. Similarly, the second
bearing
70 is pivotable about the rotation axis Al. Therefore, the second lever can
press the
inner surface of the third hole 77 of the second bearing 70 in an optimum
direction
without rotating the casing 10.
[0089] In addition, when the developing cartridge 1 moves from the contact
position to the
separated position, the first bearing 60 moves along the second guide surface
94. Fur-
thermore, the second bearing 70 moves along the fourth guide surface. In this
manner,
the first lever 97 can press the first bearing 60 while maintaining the
position of the
first bearing 60 relative to the rotation axis Al serving as the central
point. Fur-
thermore, the second lever can press the second bearing 70 while maintaining
the
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position of the second bearing 70 relative to the rotation axis Al serving as
the central
point.
[0090] <7. Modifications>
While an embodiment of the present disclosure has been described above, the
present
disclosure is not limited to the above-described embodiment. A variety of modi-
fications are described below, focusing on differences between the
modifications and
the above-described embodiment.
[0091] <7-1. First Modification>
The first modification is a modification relating to a mechanism for operating
the
first lever 97 of the drum cartridge 2. Fig. 15 is a side view of the drum
cartridge 2 of
the first modification. In Fig. 15, the drum frame 91 is denoted by a two-dot
chain line.
In the example of Fig. 15, the drum cartridge 2 does not include the first cam
99. The
first lever 97 has a projection 972 for receiving a drive from the image
forming
apparatus. When the separating operation is performed, the image forming
apparatus
presses the projection 972 of the first lever 97. As a result, the first lever
97 pivots
about a rotation shaft extending in the first direction. As described above,
if the need
for the first cam 99 is eliminated, the number of parts of the developing
cartridge 1 can
be reduced more.
[0092] <7-2. Second Modification>
The second modification is another modification relating to a structure for
restricting
the rotation range of the first bearing 60. Fig. 16 is a side view of a first
bearing 60
according to the second modification. In the example of Fig. 16, the first
bearing 60
has a second hole 68 in the second end portion 62. The second hole 68 extends
in the
first direction from the surface of the second end portion 62 of the first
bearing 60 on
the other side in the first direction toward the surface on the one side in
the first
direction.
[0093] In addition, in the example of Fig. 16, a casing 10 has a casing
shaft 16. The casing
shaft 16 extends in the first direction from the first outer surface 11 of the
casing 10
toward one side in the first direction. The casing shaft 16 is inserted into
the second
hole 68 of the first bearing 60.
[0094] As illustrated in Fig. 16, a length dl of the second hole 68 is
longer than a length d2
of the casing shaft 16 in the pivotal direction of the second end portion 62
about the
rotation axis Al. In addition, the second hole 68 has a first inner side
surface 681 and a
second inner side surface 682. The first inner side surface 681 and the second
inner
side surface 682 are separated from each other in the above-described pivotal
direction.
[0095] Like the above-described embodiment, the first bearing 60 is
pivotable about the
rotation axis Al between a first position (the position denoted by a two-dot
chain line
illustrated in Fig. 16) and a second position (the position denoted by a solid
line in
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Fig.15). When the first bearing 60 is located at the first position, the
casing shaft 16 is
in contact with the first inner side surface 681. In contrast, when the first
bearing 60 is
located at the second position, the casing shaft 16 is in contact with the
second inner
side surface 682. Thus, the rotation range of the first bearing 60 is
restricted.
[0096] <7-3. Other Modifications>
According to the above-described embodiment, the developing cartridge 1
includes
the first bearing and the second bearing. The first bearing and the second
bearing have
the same shape, and both are pivotable with respect to the casing 10. However,
the
second bearing may have a shape that differs from that of the first bearing.
In addition,
the second bearing may be non-pivotable with respect to the casing 10.
Furthermore,
the developing cartridge 1 does not necessarily have to include the second
bearing. In
this case, the first bearing can be placed at either one of the ends of the
casing 10 in the
first direction.
[0097] According to the above-described embodiment, the developing
cartridge 1 is
mounted on the drum cartridge 2 including only one photosensitive drum 92.
However,
the developing cartridge 1 may be mounted on a drum cartridge including a
plurality of
photosensitive drums 92.
[0098] Furthermore, the shape of the detail of the developing cartridge 1
may differ from the
shape illustrated in any one of the drawings of the present application. In
addition, the
elements appearing in the above-described embodiment and modifications may be
combined in any way as long as no conflicts occurs.
Reference Signs List
[0099] 1 developing cartridge
2 drum cartridge
casing
11 first outer surface
12 second outer surface
13 Containment room
14 opening
casing recess
16 casing shaft
agitator
developing roller
31 developing roller main body
32 developing roller shaft
supply roller
41 supply roller body
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PCT/JP2020/012280
42 supply roller shaft
50 gear unit
51 agitator gear
52 developing roller gear
53 supply roller gear
54 coupling
55 gear cover
60 first bearing
61 first end portion
62 second end portion
63 first arm
64 second arm
65 first shaft hole
66 bearing shaft
67 first hole
68 second hole
70 second bearing
71 third end portion
72 fourth end portion
73 third arm
74 fourth arm
75 second shaft hole
76 hook portion
77 third hole
91 drum frame
92 photosensitive drum
93 first guide surface
94 second guide surface
95 first movable member
96 first coil spring
97 first lever
98 electrode terminal
99 first cam
Al rotation axis
Date Recue/Date Received 2024-04-05
