Information
-
Patent Grant
-
6334035
-
Patent Number
6,334,035
-
Date Filed
Thursday, February 17, 200024 years ago
-
Date Issued
Tuesday, December 25, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Fitzpatrick, Cella, Harper & Scinto
-
CPC
-
US Classifications
Field of Search
US
- 399 106
- 399 103
- 399 102
- 399 262
- 399 258
- 222 DIG 1
-
International Classifications
-
Abstract
A developer container which has a container main body includes an opening through which a developer is supplied, a seal member for unsealably sealing the opening, and a drive source for applying a force for unsealing the seal member. The drive source has an elastic member and the drive source applies the unsealing force using a restoring force of the elastic member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a developer container for use in an image forming apparatus such as an electrophotographic apparatus, and a cartridge detachably attachable to the image forming apparatus.
Examples of image forming apparatuses include electrophotographic copiers, electrophotographic printers (for example, laser printers and LED printers or the like), facsimile terminal equipment, and word processors or the like.
In addition, as cartridges for image forming apparatuses, for example, process cartridges are used. The process cartridge comprises at least one of charging means and cleaning means, an electrophotographic photosensitive member that is an image bearing member (bearer), and developing means, which are integrated as a cartridge and are detachably attachable to an image-forming-apparatus main body. Alternatively, the process cartridge comprises at least developing means and an electrophotographic photosensitive member, which are integrated as a cartridge and are detachably attachable to an image-forming-apparatus main body.
In addition, a developing apparatus contains (houses) a developer for developing an electrostatic image formed on an electrophotographic photosensitive member and uses developing means to develop the electrostatic image with the developer in order to visualize the image.
2. Related Background Art
Conventional electrophotographic image forming apparatuses using an electrophotographic-image-forming process are based on a process-cartridge method for integrating an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member, together as a cartridge and detachably attaching this cartridge to an image-forming-apparatus main body. This process-cartridge method enables users to carry out maintenance work for the apparatus without relying on service personnel, thereby substantially improving operability. Thus, the process-cartridge method is commonly used in image forming apparatuses.
In such a process cartridge, a toner container that is a developer container configuring part of a developing apparatus has an opening for supplying a developing-container side with a toner (a developer) contained in the toner container. This opening is sealed with a toner seal that is a seal member while the process cartridge is unused. When the process cartridge is used, a folded-back portion of the toner seal is unsealed by pulling the seal in the folding-back direction, thereby enabling the toner to be supplied to the developing-container side from the toner container.
In order to automatically unseal the toner seal, automatic unsealing mechanisms have been proposed that automatically unseal the toner seal by winding up the folded-back portion of the toner seal around a winding member, such as a winding shaft, via an operational force applied upon installation of the process cartridge in the image-forming-apparatus main body or via a power-transmission device, such as a gear, which is driven by a motor upon the installation of the process cartridge in the image-forming-apparatus main body (Japanese Patent Application Laid-Open No. 1-193872, Japanese Utility Model Application Laid-Open No. 62-110954, Japanese Patent Application Laid-Open No. 62-127876, etc.).
Thus, a simple inexpensive configuration has been desired as a mechanism for automatically unsealing the toner seal member.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a developer container and a cartridge that enable a seal member to be automatically unsealed using a simple configuration.
Other objects and features of the present invention will be apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a typical explanatory drawing of a configuration of a process cartridge;
FIG. 2
is an explanatory drawing of a toner-seal sticking configuration and an automatic toner-seal unsealing mechanism;
FIG. 3
is a top view showing how the process cartridge is inserted into an image forming apparatus main body;
FIG. 4
is an explanatory drawing showing a state where the charging condition of a restoring force of a constant-load spring effected by a stopper is released (canceled);
FIG. 5
is a typical explanatory drawing of an electrophotographic image forming apparatus with the process cartridge installed therein;
FIG. 6
is a vertical, sectional view of the process cartridge showing an embodiment of the present invention;
FIG. 7
is a perspective view of a toner-container section of the process cartridge in
FIG. 6
(before winding);
FIG. 8
is a perspective view of a toner-container section of the process cartridge in
FIG. 1
(during winding);
FIG. 9
is a front view of the process cartridge in
FIG. 2
as seen from a developing-container side;
FIG. 10
is a diagram showing the relationship between the winding length of a toner seal and toner-seal winding force;
FIG. 11
is a plan view showing a state where the process cartridge in
FIG. 6
is installed in an image forming apparatus;
FIG. 12
is a perspective view showing the positional relationship between a gear and stopper of the process cartridge in
FIG. 11 and a
rack of the image forming apparatus;
FIG. 13
is a perspective view of a configuration for winding an unsealing start portion of the toner seal by interlocking with a main-body cover;
FIG. 14
is a plan view showing how a process cartridge configured to start unsealing the toner seal using a cam and a cam follower is installed in the image forming apparatus;
FIG. 15
is a perspective view showing the positional relationship between a gear and stopper of the process cartridge in
FIG. 14 and a
rack of the image forming apparatus;
FIG. 16
is a vertical sectional view of an electrophotographic image forming apparatus;
FIG. 17
is a perspective view of a toner-container section of a process cartridge showing an embodiment of the present invention;
FIG. 18
is a perspective view of a toner-container section of a process cartridge showing an embodiment of the present invention;
FIG. 19
shows a graph of the toner-seal unsealing strength and a corresponding pattern of a welded portion;
FIG. 20
is a graph of the toner-seal unsealing strength, a winding force applied by a spring, and a load required to prevent the spring from loosening;
FIG. 21
shows a modeled constant-load spring;
FIGS. 22A
,
22
B, and
22
C each show a toner-seal welding pattern obtained if the angle of a welding tip portion or the welding width is varied;
FIG. 23
is a plan view of a cartridge-installation portion of an image-forming-apparatus main body; and
FIG. 24
is a front view of a toner seal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described below in detail with reference to the drawings.
In the embodiments, a laser beam printer is explained as an embodiment of an electrophotographic image forming apparatus.
First, a process cartridge and an electrophotographic image forming apparatus that allows the process cartridge to be installed therein will specifically be described with reference to
FIGS. 1 and 5
.
FIG. 1
is a typical explanatory drawing of a configuration of a process cartridge.
FIG. 5
is a typical explanatory drawing of a configuration of an electrophotographic image forming apparatus with the process cartridge installed therein.
In the course of the following description, the general configuration of the electrophotographic image forming apparatus is first explained and the configuration of the process cartridge is then explained.
(General Configuration)
As shown in
FIG. 5
, an electrophotographic image forming apparatus (a laser beam printer) A irradiates an electrophotographic photosensitive member
15
that is a drum-shaped image bearer (hereafter referred to as a “photosensitive member drum”) with information light based on image information from optics
25
, in order to form an electrostatic latent image on the photosensitive-member drum
15
. The electrophotographic image forming apparatus then develops this electrostatic latent image with a developer (hereafter referred to as a “toner”) to form a toner image. In synchronism with the formation of the toner image, recording media (recording materials, OHP sheets, cloths, etc.) are separated and fed one by one from a cassette
21
a
accommodating them, using a pickup roller
21
b
and a pressure contact member
21
c
that is in pressure contact therewith. The recording medium
20
is conveyed by a convey means
21
, consisting of a pair of convey rollers
21
d
, a pair of registration rollers
21
e
, and other components, and the toner image formed on the photosensitive-member drum
15
, which is integrated into a cartridge as a process cartridge B, is applied under voltage to a transfer roller
22
that is transfer means, whereby the image is transferred to the recording medium
20
. The recording medium
20
is then conveyed to fixing means
23
by means of a convey belt
21
f
. The fixing means
23
consists of a drive roller
23
a
and a fixing roller
23
d
comprised of a cylindrical sheet that incorporates a heater
23
b
and that is rotatably supported by a support
23
c
. The fixing means
23
applies heat and pressure to the passing recording medium
20
to fix the transferred toner image thereto. The recording medium
20
is then conveyed by a pair of discharging rollers
21
g
,
21
h
and discharged to a discharge portion
24
through a turnover convey path. The image forming apparatus A enables manual feeding using a manual-feeding tray
21
i
and a roller
21
j.
(Process Cartridge)
On the other hand, the process cartridge
1
comprises an electrophotographic photosensitive member and at least one process means. The process means may be, for example, charging means for charging the electrophotographic photosensitive member, developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member, or cleaning means for removing a toner remaining on a surface of the electrophotographic photosensitive member or the like.
The process cartridge
1
shown in this embodiment is configured to rotate the photosensitive-member drum that is an electrophotographic photosensitive member having a photosensitive layer, to apply a voltage to a charging roller
16
that is the charging means in order to uniformly charge a surface of the photosensitive-member drum
15
, to expose the charged photosensitive-member drum
15
to an optical image from the optics
25
via an exposure opening (not shown) to form an electrostatic latent image, and to develop the electrostatic latent image using developing means
5
, as shown in FIG.
1
. That is, the charging roller
16
is provided in contact with the photosensitive-member drum for charging. The charging roller
16
rotates in a fashion following the photosensitive-member drum
15
.
The developing means
5
feeds a toner T in a toner container
4
to an opening
6
in the toner container
4
using a rotatable toner feeding member (not shown) and then feeds the toner into a developing container
3
through the opening
6
. Then, the toner is agitated by a toner agitating member (not shown), and a developing sleeve
5
a
in the form of a developer bearer incorporating a fixed magnet is rotated, while a developing blade
5
b
forms on a surface of the developing sleeve
5
a
, a toner layer to which frictionally charged charges are applied. The toner is then shifted to the photosensitive-member drum
15
depending on the electrostatic latent image to visibly form a toner image.
Then, a voltage of a polarity opposite to that of the toner image is applied to the transfer roller
22
to transfer the toner image to the recording medium
20
, and cleaning means
17
removes a residual toner on the photosensitive-member drum
15
by scraping off the residual toner using a cleaning blade
17
a
, while scooping it up using a scoop sheet
17
b
, so that it is removed-toner containing portion
17
c.
The members including the photosensitive-member drum
15
, the charging roller
16
, and the developing sleeve
5
a
or the like are contained in a cartridge flame configured by coupling a developing unit
1
A that is a developing device and a cleaning container
2
together, thereby configuring a cartridge. The cartridge is installed in cartridge-installation means (see
FIG. 3
) detachably/attachable in the direction of arrow C (see FIG.
5
), the cartridge-installation means being provided in an image-forming-apparatus main body
26
. The developing unit
1
A joins a toner container
4
that is a developer container configuring a toner containing portion
4
a
and supporting the toner feeding member for rotative driving, with the developing container
3
incorporating developing members including the toner agitating member, the developing sleeve
5
a
, and the developing blade
5
b
, whereby the developing unit
1
A is integrated with the toner container
4
and the developing container
3
. The cleaning container
2
constitutes the removed-toner containing portion
17
c
and supports the photosensitive-member drum
15
, the cleaning blade
17
a
, the scoop sheet
17
b
, and the charging roller
16
. The developing unit
1
A and the cleaning container
2
are coupled together to constitute the cartridge frame.
With respect to the cartridge-installation means, when an opening and closing member
27
is opened around a shaft
27
a
provided in the image-forming-apparatus main body
26
, a space in the cartridge-installation portion is exposed as shown in
FIG. 5
; guide rails B are disposed to the right and left of this space as cartridge-installation guide members (see FIG.
3
). Guides (not shown), each consisting of a boss and a rib provided on a corresponding one of the both outer side surfaces of the process cartridge extending in its longitudinal direction (the axial direction of the photosensitive-member drum
15
), are each fitted in the guide rail B and guided therethrough, so that the process cartridge
1
is installed in the image-forming-apparatus main body
26
in the direction of arrow C.
(Toner-Seal Sticking Configuration)
Next, a toner-seal sticking configuration for sealing the opening in the developing unit will be described with reference to
FIGS. 1 and 2
.
FIG. 2
is an explanatory drawing of the toner-seal sticking configuration and an automatic toner-seal unsealing mechanism.
As shown in
FIG. 1
, the toner container
4
of the developing unit
1
A has the toner T contained in its toner containing portion
4
a
and has the opening
6
in a surface
4
b
opposed to the developing sleeve
5
of the toner container
4
in order to supply the developing sleeve
5
with the toner T in the toner-containing portion
4
a
(see FIG.
2
). The opening
6
extends in a longitudinal direction (an axial direction of the developing sleeve
5
) of the developing unit
1
A as shown in FIG.
2
. In
FIG. 2
, the developing container
3
of the developing device is omitted. The toner container
4
has a toner seal
7
, that is, a seal member welded on the surface
4
b
along the edges of four sides of the opening
6
in such a manner as to occlude the opening
6
. The toner seal
7
has a folded-back portion
7
a
at one longitudinal end of the opening
6
, with a tip
7
a
1
of the folded-back portion
7
a
fixed to a winding portion
8
a
of a seal winding shaft
8
of an automatic unsealing mechanism M, which will be described below. In this manner, the toner seal
7
seals the opening
6
in the toner container
4
to block both the toner T in the toner container
4
and the developing sleeve
5
in the developing container
3
while the process cartridge
1
is unused.
(Configuration of the Automatic Toner-Seal Unsealing Mechanism)
Next, a configuration of the automatic toner-seal unsealing mechanism will be explained with reference to FIG.
2
.
As shown in
FIG. 2
, the automatic unsealing mechanism M shown in this embodiment has the seal winding shaft
8
that is a winding member, a rotative-drive source
9
, and a stopper
11
that is holding means. The seal winding shaft
8
, the rotative-drive source
9
, and the stopper
11
are attached to a support table
4
c
provided on a side surface of the toner container
4
so as to project in the longitudinal direction of the developing unit
1
A, the side surface being located at the tip
7
a
1
of the folded-back portion
7
a
of the toner seal
7
.
The seal winding shaft
8
is rotatively supported on the support table
4
c
in a direction parallel with the surface
4
b
of the toner container
4
described above. In particular, the seal winding shaft
8
is rotatably supported on the support table
4
c
via a seal member
10
such as an oil seal, which has a sealing capability, thereby preventing the toner in the toner container
4
from leaking to the exterior. In addition, the seal winding shaft
8
has a winding portion
8
a
in the toner container
4
. The winding portion
8
a
has the tip
7
a
1
of the toner seal
7
fixed thereto by means of screwing, welding, or adhesion. The seal winding shaft
8
has its lower end fitted in a hole (not shown) in the toner container
4
and its upper end fitted in a hole
13
b
in a holder
13
subsequently attached to the support table
4
c
of the toner container
4
. The seal winding shaft
8
is rotatably held by the toner container
4
and the holder
13
.
The rotative-drive source
9
is configured by a constant-load spring acting as an elastic member such that a restoring force of the constant-load spring is used to rotate the seal winding shaft
8
. That is, the constant-load spring
9
acting as an elastic member that is a rotative-drive source has the other end fixed to a spring support shaft
9
a
fixedly supported on the support table
4
c
in parallel with the seal winding shaft
8
, while having one end fixed to the seal winding shaft
8
by means of screwing. The spring support shaft
9
a
has a lower end fitted in a hole (not shown) in the support table
4
c
and an upper end fitted in a hole
13
c
in the holder
13
, and is held by the support table
4
c
and the holder
13
. The constant-load spring
9
shown in this embodiment has one end fixed to the seal winding shaft
8
with a restoring force charged beforehand so as to rotate the seal winding shaft
8
to wind the toner seal
7
. In this manner, the constant-load spring
9
has one end fixed to the seal winding shaft
8
with the restoring force charged, thereby enabling the toner seal
7
to be completely unwound and unsealed.
Although this embodiment uses the constant-load spring
9
as an elastic member that is a rotative drive source, a (flat) spiral spring may be used instead of the constant-load spring
9
. This is because the constant-load spring or flat spiral spring can be subjected to a relatively large deflection, whereby it is suitable for a case where the seal winding shaft
8
to which one end of the toner seal
7
is fixed is rotated to pull and unseal the toner seal
7
in the longitudinal direction.
The stopper
11
is rotatably attached to a stopper-support shaft
11
c
fixedly supported on the support table
4
c
in parallel with the seal winding shaft
8
. The stopper-support shaft
11
c
has a lower end fitted in a hole (not shown) in the support table
4
c
and an upper end fitted in a hole
13
d
in the holder
13
, and is held by the support table
4
c
and the holder
13
. The stopper
11
integrally has a holding section
11
a
for holding the constant-load spring
9
in such a manner that its restoring force can be charged, and an arm portion
11
b
for releasing the charged state of the constant-load spring
9
. The stopper
11
engagingly locks the holding portion
11
a
in a notch
12
a
in a pedestal
12
fixedly provided around an upper part of the seal winding shaft
8
to hold the restoring force of the constant-load spring
9
charged. In this manner, according to this embodiment, the toner seal
7
is prevented from temporal fatigue by allowing the pedestal
12
provided around the seal winding shaft
8
to be held by the holding portion
11
a
of the stopper
11
, thereby hindering the restoring force of the constant-load spring
9
from being transmitted to the toner seal
7
. In addition, when pressed by a pin
14
in the form of a projection that is a releasing member of the image-forming-apparatus main body
26
, which will be described below, the arm portion
11
b
of the stopper
11
is rotated in the direction of arrow D to remove the holding portion
11
a
from the notch
12
a
in the pedestal
12
, thereby releasing the charged state of the restoring force of the constant-load spring
9
.
As described above, the parts provided on the support table
4
c
of the developing unit
1
A and including the seal winding shaft
8
, the constant-load spring
9
, the stopper
11
, and the pedestal
12
are housed inside the holder
13
attached to the support table
4
c
. The holder
13
has a groove
13
a
formed in a side surface thereof and into which the pin
14
of the image-forming-apparatus main body
26
advances. In addition, the holder
13
has the holes
13
b
,
13
c
, and
13
d
formed in a top surface thereof, wherein an upper end of the seal winding shaft
8
is fitted in the hole
13
b
, wherein an upper end of the spring support shaft
9
a
is fitted in the hole
13
c
, and wherein an upper end of the stopper-support shaft
11
c
is fitted in the hole
13
d
. The holder
13
is assembled on the support table
4
c
after the seal winding shaft
8
, the constant-load spring
9
, and the stopper
11
have been attached to the support table
4
c.
(Description of the Pin (the Releasing Member) of the Image-Forming-Apparatus Main Body)
Next, the pin of the image-forming-apparatus main body will be explained with reference to FIG.
3
.
FIG. 3
is a top view showing how the process cartridge is inserted into the image-forming-apparatus main body.
As shown in
FIG. 3
, the process cartridge
1
is inserted into the image-forming-apparatus main body
26
along the guide rails B in the insertion direction indicated by arrow C. The image-forming-apparatus main body
26
has the pin
14
in the longitudinal direction of the process cartridge
1
(the axial direction of the photosensitive member drum
15
) and opposite to the holder
13
of the developing unit
1
A, the pin being in the form of a projection and operating as a releasing member. When the process cartridge
1
is inserted close to a regular installation position, which is shown in
FIG. 5
, the pin
14
advances into the groove
13
a
formed in the side surface of the holder
13
to abut on the arm portion
11
b
of the stopper
11
, thereby releasing the charging of the restoring force of the constant-load spring
9
effected by the stopper
11
. Thus, the restoring force of the constant-load spring
9
rotates the seal winding shaft
8
to automatically unseal the toner seal
7
.
(Description of Automatic Toner-Seal Unsealing (Automatic Winding))
Next, automatic toner-seal unsealing will be explained in detail with reference to FIG.
4
.
FIG. 4
is an explanatory drawing showing how the charging of the restoring force of the constant-load spring effected by the stopper is released.
As shown in
FIG. 4
, before the process cartridge
1
is inserted into the regular installation position shown in
FIG. 5
, the stopper
11
engagingly locks its holding portion
11
a
in the notch
12
a
in the pedestal
12
to hold the restoring force of the constant-load spring
9
(not shown) charged. When the process cartridge
1
is further inserted from the position shown in
FIG. 4
, a tip
14
a
of the pin
14
abuts on the arm portion
11
b
of the stopper
11
to press it to rotate the stopper
11
around the stopper support shaft
11
c
in the direction of arrow D. The holding portion
11
a
of the stopper
11
is thereby taken off the notch
12
a
of the pedestal
12
, while simultaneously the charging of the restoring force of the constant-load spring
9
effected by the stopper
11
is released, thereby rotating the seal winding shaft
8
in the direction of arrow E due to the restoring force of the constant-load spring
9
to wind and unseal the toner seal
7
.
Shown below is an example of the dimensions of the constant-load spring
9
, which is associated with a pull-out force (a winding force) applied to the toner seal
7
by the rotation of the seal winding shaft
8
in the process cartridge
1
according to this embodiment.
A pull-out force that must be applied to the toner seal
7
is assumed to be 3 [kgf] (3×9.806{tilde over (=)}29.4 N). If the seal winding shaft
8
has an axial diameter of 8 [mm], a required axial torque is 12 [kgf.mm] (12×9.806{tilde over (=)}117.7 J). In addition, the torque of the constant-load spring
9
depends on its material, radius of curvature, board thickness, and board width. If the material of the constant-load spring
9
is SUS301CSP-EH (elastic modulus E=19,300) [kgf.mm
2
]), its radius of curvature is 10 [mm], its board width is 12 [mm], and its board thickness is 0.15 [m]), then the axial torque is 13 [kgf.mm] (13×9.806{tilde over (=)}127.5 N.mm) and the pull-out force is 3.26 [kgf] (3.26×9.806{tilde over (=)}32.0 N), which meets the above requirement for the pull-out force for the toner seal
7
, that is, 3 [kgf] (3×9.806{tilde over (=)}29.4 N).
Accordingly, if the constant-load spring
9
is used as an elastic member that is a rotative-drive source, a pull-out force can be obtained which is sufficient to rotate the seal winding shaft
8
to pull out the toner seal
7
.
As described above, in the developing unit
1
A comprising the automatic unsealing mechanism M and the process cartridge
1
having the developing unit
1
A, both of which are shown in this embodiment, the constant-load spring
9
that is an elastic member is used as a rotative-drive source for rotating the seal winding shaft
8
. Consequently, the toner seal
7
can be unsealed automatically without the use of a power transmission device, such as a gear, which is driven by a motor as in the above-discussed conventional process cartridge. Besides, the automatic unsealing mechanism M has a simple configuration due to the elimination of the need for a motor and a gear used as transmission devices. In addition, the present drive source for winding up the toner seal serves to reduce manufacturing costs compared to process cartridges with a motor integrated therein. Further, the present drive source for winding up the toner seal advantageously serves to reduce the burden on users compared to process cartridges that require manual winding based on rotation of a handle provided in the process cartridge.
In addition, since only the winding portion
8
a
of the seal winding shaft
8
with the toner seal
7
fixed thereto is contained in the toner container
4
, the toner seal
7
is contained in the toner container
4
after winding. By containing the toner seal
7
in the toner container
4
in this manner, opposed surfaces of the toner container
4
and developing container
3
can be welded perfectly, thereby eliminating the need for an opening through which the toner seal
7
is pulled out from the process cartridge
1
. This configuration also eliminates the need for a seal member used in the prior art for prevention of blowcut of the toner.
In addition, the toner seal
7
is contained inside the toner container
4
, whereby the user can prevent the toner seal
7
from being contaminated with a trace amount of toner adhering thereto, without the need to process the toner seal
7
.
Further, since the seal winding shaft
8
is supported by the support
4
c
using the seal member
10
such as an oil seal which has a sealing capability, the toner in the toner container
4
is prevented from leaking to the exterior.
In addition, the constant-load spring
9
acting as an elastic member that is a rotative-drive source is disposed outside the toner container
4
, so that it can be replaced easily with a new one for reuse.
Further, the toner seal
7
is prevented from temporal fatigue because the pedestal
12
provided around the seal winding shaft
8
is held by the holding section
11
a
of the stopper
11
to hinder the restoring force of the constant-load spring
9
from being transmitted to the toner seal
7
.
In addition, since the pin
14
provided on the image-forming-apparatus main body
26
advances into the groove
13
a
in the holder
13
of the developing unit
1
A to accommodate the stopper
11
inside the holder
13
, the user is prevented from mistakenly releasing the charging of the restoring force of the constant-load spring
9
effected by the stopper
11
before installing the process cartridge
1
in the image-forming-apparatus main body
26
.
Embodiment 2
[General Configuration]
As shown in
FIG. 16
, this electrophotographic image forming apparatus (laser beam printer) K irradiates a drum-shaped electrophotographic photosensitive member with a laser light image based on image information from optics
121
to form a latent image on the photosensitive member, and then develops this latent image to form a toner image. In synchronism with the formation of the toner image, a recording medium
122
is conveyed by convey means
123
consisting of a pickup roller
123
b
, a pair of registration rollers
123
c
, and other components, and the toner image formed on the photosensitive member drum is applied under voltage to a transfer roller
124
that is transfer means, whereby the image is transferred to the recording medium
122
. The recording medium
122
is then conveyed to fixing means
125
by means of a guide plate
123
d
. The fixing means
125
consists of a drive roller
125
a
and a fixing roller
125
c
incorporating a heater
125
b
, and applies heat and pressure to the passing recording medium
122
to fix the transferred toner image thereto. The recording medium
122
is then conveyed by a pair of discharging rollers
123
e
,
123
f
and discharged to a discharge portion
126
through a turnover convey path. The image forming apparatus K enables manual feeding using a manual-feeding tray
123
g
and a roller
123
h.
On the other hand, the process cartridge
101
comprises an electrophotographic photosensitive member and at least one process means, as shown in FIG.
6
. The process means may be, for example, charging means for charging the electrophotographic photosensitive member, developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member, or cleaning means for cleaning a toner remaining on a surface of the electrophotographic photosensitive member. The process cartridge
101
according to this embodiment is configured to rotate a photosensitive member drum
127
that is an electrophotographic photosensitive member, to apply a voltage to a charging roller
128
that is the charging means in order to uniformly charge a surface of the photosensitive member drum
127
, to expose the charged photosensitive member drum
127
to information light from the optics
121
to form a latent image, and to develop the latent image using developing means
130
, as shown in FIG.
6
. The developing means
130
feeds a toner T in a toner container
104
through an opening
106
using a toner feeding member (not shown). A developing sleeve
105
incorporating a fixed magnet
105
c
is rotated, while a developing blade
105
e
forms on a surface of the developing sleeve
105
, a toner layer to which frictionally charged charges are applied. The toner is then shifted to the photosensitive member drum
127
in accordance with the latent image to visualized by forming a toner image. Then, a voltage of a polarity opposite to that of the toner image is applied to a transfer roller
124
to transfer the toner image to the recording medium
122
and cleaning means
102
then removes a residual toner on the photosensitive member drum
127
by scraping off the residual toner using a cleaning blade
102
a
, while scooping it up using a scoop sheet
102
b
, so that it is collected in a removed toner reservoir
102
c.
The members including the photosensitive member drum
127
are contained in a cartridge frame to form a cartridge, which is detachably/attachably installed in a cartridge installation means provided in the apparatus body K; the cartridge frame is configured as follows: a toner container
104
for containing the toner and a developing container
103
for containing developing members such as the developing sleeve
105
are welded together to constitute a developing unit, and this developing unit and a cleaning unit comprising a cleaning container
118
with the photosensitive member drum
127
and the cleaning means
102
attached thereto are coupled together to constitute the cartridge frame, as shown in
FIG. 6
The cartridge-installation means can be seen when a main-body cover
116
is opened around a hinge
116
a
, as shown in FIG.
16
. Cartridge-installation guide portions G are provided opposite to each other and to the right and left of a cartridge-installation space in such a manner that their front sides relative to the apparatus are lower than their rear sides. These guide portions G operate as guides during insertion of the process cartridge
101
. Bosses (not shown) projected from opposite longitudinal sides of the cartridge frame and ribs (not shown) following the bosses are guided on the guide portions G to insert the process cartridge
101
, and the main-body cover
116
is then closed to install the process cartridge
101
in the image forming apparatus K.
FIG. 6
shows a sectional view of the process cartridge. The process cartridge
101
is composed of the cleaning container
118
, the developing container
103
, the toner container
104
, and other components.
The toner container
104
has the unused toner T contained therein and has an opening
106
formed in its surface opposed to the developing sleeve
105
of the toner container
104
, the opening being used to supply the toner T to the developing sleeve
105
. While the process cartridge is unused, a seal member
107
(hereafter referred to as a “toner seal”) is welded to the opening
106
to block the developing sleeve
105
from the toner T. In addition, the toner container
104
has a seal winding shaft
108
, a constant-load spring
109
or a flat spiral spring acting as an elastic member, a gear
110
that is a segment gear, a stopper
111
, etc. formed on a side surface of the toner container
104
.
FIG. 7
shows a perspective view of the toner-container portion. As seen in
FIG. 7
, the seal winding shaft
108
is provided rotatably at the toner container
104
rotation. The seal winding shaft
108
has an elastic member, such as the constant-load spring
109
attached thereto and acting as a drive source, and also has the gear
110
attached thereto for triggering pulling of the seal. The stopper
111
is rotatably supported in the toner container
104
by means of a stopper shaft
111
c
extending parallel with the seal winding shaft
108
, in order to hold the charged state of the elastic member. The stopper
111
abuts on a pin
110
b
fixed to the gear
110
to stop the rotation of the gear
110
effected by the constant-load spring
109
. The stopper shaft
111
c
is located on a tangent to a circle having its center at the shaft
108
and passing through the pin
110
b
. The stopper
111
is in the form of a bell crank having two arms, that is, a stop arm
111
b
and an operative arm
111
a
. The elastic member
109
or the like is contained in a holder
112
attached to the toner container
104
. The seal winding shaft
108
has one end of the toner seal
107
fixed thereto by means of screwing, welding, or adhesion. In addition, since one end of the constant-load spring
109
is fixed to the seal winding shaft
108
by screwing or the like, the toner seal
107
can be wound up by rotating the shaft based on a restoring force of the constant-load spring
109
. Further, the gear
110
is fixed to the seal winding shaft
108
so as to rotate integrally with this shaft
108
. The constant-load spring or flat spiral spring can be subjected to a relatively large deflection, whereby it is suitable for a case where the toner seal is pulled in the longitudinal direction. The pin
110
b
of the gear
110
is stopped by the stopper
111
to hold the constant-load spring
109
in he charged state.
FIG. 8
is a perspective view of the toner container
104
showing that the stopper
111
has been released and that the toner seal
107
is being wound up. The stopper
111
is released by rotating it in the direction of arrow AA, and the toner seal
107
is wound up in the direction of arrow F by rotating the seal winding shaft
108
in the direction of the arrow BB using a spring force of the constant-load spring
109
.
FIG. 9
is a front view of the toner container
104
as seen from the developing-container side. The toner seal
107
has a cover-seal portion
107
a
welded to the toner container
104
in a fashion surrounding a periphery of the opening
106
(oblique lined portion) in the toner vessel
104
. The toner seal
107
is folded back at a folded-back portion
107
b
at a corresponding end of the cover-seal portion
107
a
so as to overlap the cover-seal portion
107
a
, and is fixed to the shaft
108
on the other side. To unseal the toner seal
107
, a welded portion close to the folded-back portion
107
b
is peeled off within a range D, and the toner seal
107
is torn up at a welded portion within a range EE. The force required for unsealing is as shown in
FIG. 10
, and is large within the range D and small within the range E. To wind up the toner seal
107
within the range DD, the gear
110
shown in
FIG. 7
is rotated in synchronism with an operation for installing the process cartridge
101
in an apparatus body FF. After the toner seal
107
within the range DD has been wound up, the toner seal
107
within the range E is wound up because of the restoring force of the constant-load spring
109
. That is, the constant-load spring
109
is not required to have a force sufficient to peel off the toner seal
107
within the range DD to wind it up.
FIG. 11
is a top view showing how the process cartridge
101
is installed in the image-forming-apparatus main body FF. The process cartridge
101
is inserted into the image-forming-apparatus main body FF in the direction indicated by arrow H by sliding guide portions (not shown) of the process cartridge
101
along the guides G provided in the apparatus main body FF. When the process cartridge
101
has been inserted close to a normal installation position, a rack member
113
provided in the apparatus main body FF is inserted through a groove
112
a
formed in a side surface of the holder
112
shown in FIG.
7
.
FIG. 12
shows the relationship of position between the gear
110
, the stopper
111
, and the rack
113
. When the process cartridge
101
is inserted in the direction H, an abutting portion
113
a
of the rack
113
abuts on the operative arm
111
a
of the stopper
111
to rotate the stopper
111
in the direction A to remove the stop arm
111
b
from a pin
110
b
of the gear
110
, thereby releasing the stopper
111
. When the process cartridge
101
is further inserted in the direction H, the gear
110
meshes with teeth
113
b
of the rack
113
to rotate the seal winding shaft
108
in the direction B to wind up an unsealing-start welded portion of the toner seal
107
(the range D in
FIG. 9
) in a manner peeling off the toner seal. When this pulling-start welded portion has been peeled off to wind up a corresponding portion of the toner seal
107
, the gear
110
and the rack
113
are disengaged from each other and the winding based on the constant-load spring
109
is started. The rotation of the shaft
108
effected by the constant-load spring
109
causes the gear
110
to run idly. The stopper mechanism for stopping the rotation of the shaft
108
effected by the spring force of the constant-load spring
109
that is an elastic member is not limited to the provision of the stopper member, but the peeling force applied to the unsealing-start welded portion (the range D in
FIG. 9
) may be used as a stopper. In addition, by using a different combination of the rack and pinion and the stopper, the process cartridge can be prevented from misuse.
Embodiment 3
FIG. 13
shows Embodiment 3 of an automatic toner-seal unsealing mechanism.
FIG. 13
shows a case where a main-body cover
116
pivotally attached to the image-forming-apparatus main body F via a hinge
116
a
is opened and closed to rotate the gear
110
. When the process cartridge
101
is inserted into the image-forming-apparatus main body F and the main-body cover
116
is closed, an abutting portion
116
b
of the main-body cover
116
presses the rack
113
mounted in the apparatus main body F for movement in the direction of a train of rack teeth, so that the rack
113
releases the stopper
111
while rotating the gear
110
to unseal the pulling start portion of the toner seal
107
. When the main-body cover
116
has been closed completely, the gear
110
and the rack
113
are disengaged from each other, and unsealing is subsequently started due to the restoring force of the constant-load spring
109
. A coil spring or the like is provided on a lower part of the rack
113
so that the rack
113
can be moved up and down in response to opening and closing of the main-body cover
116
. Since after the unsealing, the gear is stopped at a position at which a notch
110
a
therein faces the rack
113
in order to prevent the gear
110
from meshing with the rack
113
, the gear
110
is precluded from rotating each time the main-body cover
116
is opened or closed. By using the operations for opening and closing the main-body cover
116
as means for triggering pulling of the toner seal
107
, the factors in the shakiness of the process cartridge during insertion can be reduced because unsealing is carried out after the process cartridge
101
has been positioned.
Embodiment 4
FIGS. 14 and 15
show Embodiment 4 of an automatic toner-seal unsealing mechanism.
FIGS. 14 and 15
show the use of a cam
114
with a pin
114
b
and a cam follower (for use as an actuator)
115
fixedly installed in the apparatus main body F instead of the gear and rack in Embodiment 2.
FIG. 14
is a top view showing how the process cartridge
101
is installed into the image-forming-apparatus main body F. As in the use of the rack and pinion, when the process cartridge
101
is inserted in the direction of arrow H, an abutting portion
115
a
of the cam follower
115
abuts on the operative arm
111
a
to remove a pin
114
b
from the stopper
111
. The cam
114
then starts to rotate on abutting on the abutting portion
115
b
of the cam follower
115
, thereby rotating the seal winding shaft
108
to wind up the pulling-start welded portion of the toner seal
107
. The cam follower
115
passes through the cam
114
, which can then rotate freely. Subsequently, the toner seal
107
is wound up because of the constant-load spring
109
.
FIG. 15
shows the relationship between the stopper
111
, the cam
114
, and the cam follower
115
. The cam
114
is attached to the winding shaft
108
in such a direction that the seal winding shaft
108
is rotated when a cam top side portion
114
a
is pushed. When the process cartridge is installed in the direction H, a tip
115
a
of the cam follower
115
abuts on the operative arm
111
a
of the stopper
111
to rotate the stopper
111
in the direction A so as to release it. When the process cartridge
101
is further inserted in the direction of the arrow H, the cam top side portion
114
a
of the cam
114
abuts on an abutting portion
115
b
of the cam follower
115
to rotate the seal winding shaft
108
in the direction B. After the cam
114
has rotated the shaft
108
to wind up a sufficient amount of the toner seal
107
to peel off the unsealing-start welded portion (the range D in
FIG. 9
) thereof, the seal winding shaft
108
is rotated because of the restoring force of the constant-load spring
109
to wind up the toner seal
107
. After rotating the cam
114
by a sufficient amount to peel off the unsealing-start welded portion of the toner seal
107
, the cam follower
115
passes through the cam
114
and then reaches a position at which the cam
114
is allowed to run idly by means of the constant-load spring
109
. After the toner seal has been wound up, the cam
114
is stopped at a position at which it does not abut on the cam follower
115
, whereby it does not affect the subsequent detachment/attachment of the process cartridge. That is, the cam stop side portion
114
a
rotates through about 180° (π rad) from the position in
FIG. 15
, so that a circular portion
114
c
is opposed to a corresponding side surface of the cam follower
115
in such a way as to be spaced therefrom. In this manner, the position of a winding end of the toner seal
107
is specified so that the circular portion
114
c
is opposed to the side surface of the cam follower
115
. The use of the cam and the cam follower enables easer positioning than the use of the rack and pinion. In addition, a change in shape of the cam
114
enables the winding force to be regulated for the initial unsealing. By using a different combination of the cam and cam follower and the stopper
111
, the process cartridge can be prevented from misuse.
According to this embodiment, the portion of the rack or cam follower that abuts on the stopper is provided integrally with the rack or cam follower, which is an operative member for releasing the stopper mechanism. However, the operative member having the abutting portion for releasing the stopper may be separate from the operative member for rotating the shaft
108
at the beginning of unsealing of the toner seal. seal.
If a biaxial reversely-wound constant-load spring is used as a drive source, the spring may come loose due to a large difference in the toner-seal unsealing force between the welded portions that are peeled off and the other tom-up portions.
Thus, the following embodiment provides an automatic toner seal unsealing mechanism using a constant-load spring wherein the toner-seal can be appropriately unsealed using the constant-load spring by providing conditions under which the spring is prevented from coming loose and reducing the difference in toner-seal unsealing strength.
Embodiment 5
This embodiment is a variant of the automatic toner-seal unsealing mechanism according to Embodiment 2 which is obtained by modifying part of this mechanism. Those components that are common to Embodiment 2 have the same reference numerals.
The cartridge installation means can be seen when a main-body cover
116
of the apparatus main body is opened around a hinge
116
a
, as shown in FIG.
16
. Cartridge installation guide portions G are provided opposite to each other and to the right and left of a cartridge installation space in such a manner that their front side relative to the apparatus are lower than their rear side. These guide portions G operate as guides during insertion of the process cartridge
101
. Bosses (not shown) projected from opposite longitudinal sides of the cartridge frame and ribs (not shown) following the bosses are guided on the guide portions G to insert the process cartridge
101
, and the main-body cover
116
is then closed to install the process cartridge
101
in the image forming apparatus K. A pin
220
is fixedly installed near the cartridge installation space so as to operate on an automatic unsealing device for the process cartridge
101
.
FIG. 24
is a front view showing an opening
106
in a toner container
104
. The opening
106
is sealed by the toner seal
107
and unsealed when the process cartridge
101
is first used. The toner seal
107
has a cover-seal portion
107
a
welded at its welded portion
107
c
to a corresponding edge of the opening
106
so as to cover and seal the opening
106
; a folded-back portion
107
b
located on a side of the cover-seal portion
107
a
closer to the rear of the apparatus and at which the toner seal is folded back so as to overlap the cover-seal portion
107
a
; and a pullout portion
107
d
with its end fixed to the winding shaft
108
.
The welded portion
107
c
has an intermediate portion EEE stuck to the longitudinally (a direction parallel with the photosensitive member drum) elongate rectangular opening
106
along its longitudinal edges, an unsealing start portion DDD in the form of the bottom of a ship that follows a folded-back-portion-
107
b
-side end of the intermediate portion EEE, and an unsealing end portion GG in the form of the bottom of a ship that follows the other end of the intermediate portion EEE. The welded portion
107
c
surrounds the opening
106
.
The width W
2
of the pullout portion
107
d
of the toner seal
107
is smaller than the width W
1
of the intermediate portion EEE of the welded portion
107
c
, and the cover-seal portion is located within the welded portion
107
c
. Consequently, by pulling the pullout portion
107
d
of the toner seal
107
, the unsealing start portion DDD of the cover-seal portion
107
a
is peeled off and the cover-seal portion
107
a
is torn up along a torn-up line TL to move the folded-back portion
107
b
rightward in
FIG. 24
, thereby unsealing the toner seal.
FIG. 17
shows a perspective view of a toner container of a process cartridge comprising an automatic toner-seal unsealing mechanism based on a constant-load spring. In
FIG. 17
, the toner container
104
has both the seal winding shaft
108
and the constant-load spring
109
, that is, a drive source provided at a side surface thereof, and the seal winding shaft
108
is rotatably supported by the toner container
104
or a cover (not shown) attached to the toner container. The seal winding shaft
108
has one end of the toner seal
107
fixed thereto by means of screwing, welding, or adhesion. In addition, one end of the constant-load spring
109
is also fixed to the seal winding shaft
108
by means of screwing, so that the toner seal
107
can be wound up by the rotation of the shaft effected by the restoring force of the constant-load spring
109
. The constant-load spring
109
is wound up around the seal winding shaft
108
to generate a charge force, and the stopper
111
and a gear
209
are provided for holding the constant-load spring
109
in the charged state. The gear
209
is fixed to the winding shaft
108
so as to rotate therewith. In addition, the gear
209
has a projection
209
a
, with which the stopper
111
is brought in contact to hold the charged state. The stopper
111
has a bell crank
111
b
rotatably provided on a shaft
111
c
. The other end
111
b
of the bell crank
111
b
abuts on the projection
209
a
to stop the gear
209
from rotating. That is, the gear
209
is stopped from rotating because a tangent to a circle corresponding to a locus of motion of the center of the projection
209
a
passes through the center of a shaft
111
c
of the stopper
111
. The constant-load spring
109
, the stopper
111
, and the gear
209
are accommodated inside the holder
112
. The holder
112
, which is fixed to a toner frame
104
, rotatably supports one end of each of the winding shaft
108
, the stopper shaft
111
c
, and the shaft of the constant-load spring
109
. In addition, the holder
112
has a groove
112
a
formed in a side surface thereof. When the process cartridge
101
is installed in an image-forming-apparatus main body, a pin
220
in the image-forming-apparatus main body is inserted into the groove
112
a
and abuts on the bell crank
111
a
, one end
111
a
of which faces the groove
112
a
. Then, the bell crank
111
a
rotates and the other end
111
b
thereof slips out from the projection
209
a
to release the charged state. As a result, the spring force of the constant-load spring
109
causes the winding shaft
108
to rotate to unseal the toner seal
107
. If the constant-load spring is of a biaxial reversely-wound type, a small size can be used compared to the required torque, whereas the spring may come loose without a certain amount of loads, thereby preventing winding from being completed.
FIG. 19
shows a graph of the toner-seal unsealing strength and a corresponding pattern of the welded portion. The ordinate indicates the unsealing length, and the abscissa indicates a force applied in pulling the toner seal, that is, the unsealing strength. The force applied at the beginning of unsealing D is defined as Fa, the force applied in the intermediate portion E is defined as Fb, and the force applied at the end of unsealing G is defined as Fc. For Fa and Fc, the unsealing strength is large because of the need to peel off the welded portion. For Fb, the unsealing strength is small and steady because in this portion, the welded portion is not peeled off but the toner seal is torn up.
FIG. 20
shows a graph of the toner-seal unsealing strength and the relationship between a winding force Fd applied by the spring and a load Fc required to preclude the spring from loosening. Since the diameter of the wound toner seal increases linearly with its thickness as unsealing progresses, the winding force Fd decreases with increasing unsealing length. If the unsealing strength required to prevent the spring from loosening is defined as Fc, the welded portion of the beginning of unsealing can be wound up if the unsealing strength is as shown at a in FIG.
20
. In this case, however, the spring comes loose because the unsealing strength in the intermediate portion (hereafter referred to as the “intermediate unsealing strength”) Fa is smaller than the required unsealing strength Fc. If the unsealing strength is as shown at b in
FIG. 20
, the intermediate portion can be completely unsealed because the intermediate unsealing strength Fb is larger than the required unsealing strength Fc, which prevents the spring from loosening. Complete unsealing of the intermediate portion allows the opening in the toner container to be entirely exposed, whereby no functional problem occurs without peeling off the unsealing-end welded portion.
FIG. 21
shows a modeled constant-load spring to indicate conditions under which the spring is prevented from loosening. The toner seal is wound up around a shaft
231
, while the spring is wound up around a shaft
232
. A force applied by the constant-load spring and a load F
3
originating in the toner-seal unsealing strength act on the shaft
231
, but a force F
4
is intentionally applied to the shaft
231
. Likewise, a restoring force F
2
of the constant-load spring acts on the shaft
232
. Torques effected around the shaft
231
by F
1
, F
3
, F
4
are defined as T
1
, T
3
, T
4
, and a torque effected around the shaft
232
by F
2
is defined as T
2
. In addition, if the radius of a portion of the shaft
231
around which the spring is wound beforehand is defined as R
1
, the radius of a portion of the shaft
231
around which the toner seal is wound up is defined as R
3
, and the radius of a portion of the shaft
232
around which the spring is wound up is defined as R
2
, then the following equations hold: T
1
=F
1
·R
1
, T
2
=F
2
·R
2
, T
3
=F
3
·R
3
, T
4
=F
4
·R
3
. When other load torques resulting from sliding friction or the like are defined as Tn
1
, Tn
2
, the spring does not come loose if T
1
−T
3
−T
4
−Tn
1
<T
2
−Tn
2
because the spring is prevented from loosening if the torque acting on the shaft
231
is larger than that acting on the shaft
232
. Accordingly, the intentionally applied load is determined to be T
4
≧T
1
−T
2
−T
3
−Tn
1
+Tn
2
in terms of the torque around the shaft
231
.
Thus, according to this embodiment, an oil damper
208
is added to the toner-seal winding shaft
108
as a load to increase the intermediate unsealing strength Fb, as shown in
FIGS. 17 and 18
. In
FIGS. 17 and 18
, the oil damper
208
is driven by a rotatable gear
211
meshing with the gear
209
fixed to the winding shaft
108
. When the stopper
111
is released, the constant-load spring
109
starts being wound up in the direction d in FIG.
18
. Then, the seal winding shaft
108
starts to rotate to unseal the toner seal
107
in a direction e. The gear
209
provided around the seal winding shaft
108
rotates therewith in a direction f, and the gear
211
for the oil damper
208
rotates in a direction g while applying a load to the gear
209
. Action for increasing the intermediate unsealing strength Fb corresponds to application of F
4
in FIG.
21
. In this manner, by using for the winding shaft
108
the oil damper
208
with a resistance force increasing in proportion to the rotation speed, the load on the winding shaft
108
corresponding to the intermediate unsealing strength Fb can be increased so as to reduce the difference between this load and the load on the winding shaft
108
based on the unsealing strength Fa at the beginning of unsealing.
FIGS. 22A
to
22
C show examples of toner-seal welding patterns. In
FIG. 22A
, both a welding tip portion and a welding rear-end portion are in the form of the bottom of a ship, the welding angle at which the toner seal is stuck to the bottom of a ship is a, the welding width is h, and the unsealing strength Fa=Fa
1
. In
FIG. 22B
, the welding angle is β, the welding width is h, and the unsealing strength Fa=Fa
2
. Since α≧β, the unsealing strength Fa of the welded portion is Fa
1
>Fa
2
. In addition, in
FIG. 22C
, the welding angle is α and the welding width is h′. Since h≧h′, the unsealing strength Fa of the welded portion is Fa
1
≧Fa
3
. Reducing Fa serves to reduce the size of the constant-load spring, thereby enabling the strength of the shaft to be reduced.
Since the difference between Fa and Fb can be reduced by increasing the intermediate unsealing strength Fb while reducing the unsealing strength Fa at the beginning of unsealing, a required load is preferably applied to the toner seal winding shaft
108
by reducing Fa as much as possible and designing the spring
109
depending on the resulting strength value.
Specific examples of the angles α, β and the welding widths h, h′ are shown below:
Conventional angle α=about 145° (140×π/180≈0.78 πrad), conventional h=about 3 mm
Present angle α=about 90° (0.5 πrad), present h′=about 2 mm.
Other Embodiments
Although the process cartridges shown in the above embodiments are used to form monochromatic images, the cartridge according to the present invention is applicable not only to formation of monochromatic images but also to cartridges, provided with a plurality of developing means, for forming images in a plurality of colors (for example, bicolor, tricolor, or full-color images).
In addition, the present invention may use various developing methods such as the well-known two-component magnetic-brush developing method, the cascade-developing method, the touch-down developing method, and the cloud-developing method.
Further, the electrophotographic photosensitive member is not limited to the above photosensitive-member drum, but includes, for example, the following: First, the photosensitive member comprises a photoconductor including, for example, amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OPC). The shape for mounting the photosensitive member includes, for example, a drum-shaped or belt-shaped rotor and a sheet. In general, a drum-shaped or belt-shaped rotor is used, and a drum-type photosensitive member is obtained by depositing or coating a photoconductor on a cylinder such as an aluminum alloy.
In addition, although the above embodiments use a so-called contact charging method as charging means, of course another conventional configuration may be used in which the surface of a photosensitive member drum is uniformly charged by providing metallic shields of aluminum or the like around a tungsten wire at three sides thereof, applying a high voltage to the tungsten wire, and moving the resulting positive or negative ions to the surface of the drum.
In addition to the above roller type, the charging means may be of a blade (charging blade), a pad, a block, a rod, or a wire type.
Further, the cleaning means for use in cleaning a residual toner on the photosensitive member drum may comprise a fur brush or a magnetic brush instead of the above cleaning blade.
In addition, the above-described process cartridge comprises, for example, an electrophotographic photosensitive member and at least one process means. Thus, in addition to the above embodiments, the aspects of the process cartridge include, for example, one comprising an electrophotographic photosensitive member, developing means, charging means integrated into a cartridge that is detachably attachable to the image-forming-apparatus main body, one comprising an electrophotographic photosensitive member and developing means integrated into a cartridge that is detachably attachable to the image-forming-apparatus main body, and one comprising an electrophotographic photosensitive member, developing means, and cleaning means integrated into a cartridge that is detachably attachable to the apparatus main body.
That is, the above-described process cartridge comprises at least one of charging means and cleaning means, an electrophotographic photosensitive member, and developing means integrated into a cartridge that is detachably attachable to the apparatus main body. Furthermore, it may comprise at least developing means and an electrophotographic photosensitive member integrated into a cartridge that is detachably attachable to the image forming apparatus main body. This process cartridge may be detachably attachable to the apparatus main body by the user. Thus, the user can perform maintenance work for the apparatus main body.
Furthermore, although the above embodiments illustrate the laser beam printer as an electrophotographic image forming apparatus, the present invention need not be limited to this aspect, but is of course applicable to other electrophotographic image forming apparatuses such as electrophotographic copiers, facsimile terminal equipment, or word processors.
Although in the above embodiments, the developer container is contained in part of the process cartridge and is detachably attachable to the image forming apparatus main body, the developer container may solely be detachably attachable to the image-forming-apparatus main body.
In addition, a developing device comprising a developing container and a developer container may be provided as a developing cartridge that is detachably attachable to the image-forming-apparatus main body.
Claims
- 1. A developer container comprising:a container main body including an opening through which a developer is supplied; a seal member for unsealably sealing said opening; and a drive source for applying a force for unsealing said seal member, said drive source including an elastic member and said drive source applying said unsealing force using a restoring force of the elastic member, wherein said elastic member is a constant-load spring.
- 2. The developer container according to claim 1, wherein said elastic member is a spiral spring.
- 3. The developer container according to claim 1, wherein said developer container has a rotatable winding member for winding up said seal member to unseal said seal member, and wherein said drive source applies the unsealing force to said seal member via said winding member.
- 4. The developer container according to claim 3, wherein said seal member wound up by said winding member is contained inside said container main body.
- 5. The developer container according to claim 3, wherein a winding portion of said winding member is contained inside said container main body.
- 6. The developer container according to claim 1, further comprising holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored.
- 7. The developer container according to claim 6, wherein when said developer container is installed in an image forming apparatus main body, a releasing member provided in said apparatus main body releases the holding of said holding means in the state where said restoring force is stored.
- 8. The developer container according to claim 7, wherein said releasing member is a projection abutting on said holding means.
- 9. The developer container according to claim 7, wherein interlocked with an operation for installing said developer container in said image forming apparatus main body, said releasing member releases the holding of said holding means in the state where said restoring force is stored.
- 10. The developer container according to claim 1, further comprising a driving force receiving portion for receiving a driving force unsealing said seal member, from an operative member provided in an image forming apparatus main body, when said developer container is installed in said image forming apparatus main body and unsealing of said seal member is started.
- 11. The developer container according to claim 10, wherein said driving force receiving portion receives the driving force unsealing said seal member, from said operative member, from the start of unsealing of said seal member until before the unsealing is complete.
- 12. The developer container according to claim 10, wherein interlocked with an operation for installing said developer container in said image forming apparatus main body, said driving force receiving portion receives the driving force unsealing said seal member from said operative member.
- 13. The developer container according to claim 10, wherein interlocked with an operation for closing a main body cover provided in said image forming apparatus main body, said driving force receiving portion receives the driving force unsealing said seal member from said operative member.
- 14. The developer container according to claim 10, wherein said operative member is a rack, and said driving force receiving portion is a gear meshing with said rack.
- 15. The developer container according to claim 10, wherein said operative member is a cam follower, and said driving force receiving portion is a cam engaging with said cam follower.
- 16. The developer container according to claim 1, further comprising a reduction means for reducing the difference between a load applied to said constant-load spring at the start of unsealing of said seal member and a load subsequently applied in unsealing an intermediate portion of said seal member.
- 17. The developer container according to claim 16, wherein said reduction means includes load applying means for applying a load to said constant-load spring separately from the force for unsealing said seal member when unsealing said intermediate portion of said seal member.
- 18. The developer container according to claim 17, further comprising a rotatable winding member for winding up said seal member to unseal said seal member, wherein said drive source applies the unsealing force to said seal member via said winding member, and said load applying means applies a load to said winding member.
- 19. The developer container according to claim 17, wherein the greater a speed at which said seal member is unsealed is, the greater said load applied by said load applying means.
- 20. The developer container according to claim 19, wherein said load applying means is a damper.
- 21. The developer container according to claim 19, wherein said load applying means is an oil damper.
- 22. A developer container comprising:a container main body including an opening through which a developer is supplied; a seal member for unsealably sealing said opening; a drive source for applying a force for unsealing said seal member, said drive source including an elastic member and said drive source applying said unsealing force using a restoring force of the elastic member; and holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored, wherein when said developer container is installed in an image forming apparatus main body, a releasing member provided in said apparatus main body releases the holding of said holding means in the state where said restoring force is stored, and wherein interlocked with an operation for closing a main body cover provided in said apparatus main body, said releasing member releases the holding of said holding means in the state where said restoring force is stored.
- 23. A developer container comprising:a container main body including an opening through which a developer is supplied; a seal member for unsealably sealing said opening; a drive source for applying a force for unsealing said seal member, said drive source including an elastic member and said drive source applying said unsealing force using a restoring force of the elastic member; holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored; and support means provided outside said container main body to support said holding means, wherein said holding means is covered by said support means.
- 24. A cartridge detachably attachable to an image forming apparatus main body comprising:a developer bearing member for bearing a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer container for supplying the developer toward said developer bearing member, said developer container including a container main body having an opening through which the developer is supplied and a seal member for unsealably sealing said opening; and a drive source for applying a force for unsealing said seal member, said drive source including an elastic member to apply said unsealing force using a restoring force of said elastic member, wherein said elastic member is a constant-load spring.
- 25. The cartridge according to claim 24, wherein said elastic member is a spiral spring.
- 26. The cartridge according to claim 24, wherein said cartridge has a rotatable winding member for winding up said seal member to unseal said seal member, and said drive source applies the unsealing force to said seal member via said winding member.
- 27. The cartridge according to claim 26, wherein said seal member wound up by said winding member is contained inside said container main body.
- 28. The cartridge according to claim 26, wherein a winding portion of said winding member is contained inside said container main body.
- 29. The cartridge according to claim 24, wherein said cartridge has holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored.
- 30. The cartridge according to claim 29, wherein when said developer container is installed in said image forming apparatus main body, a releasing member provided in said apparatus main body releases the holding of said holding means in the state where said restoring force is stored.
- 31. The cartridge according to claim 30, wherein said releasing member is a projection abutting on said holding means.
- 32. The cartridge according to claim 30, wherein interlocked with an operation for installing said cartridge in said image forming apparatus main body, said releasing member releases the holding of said holding means in the state where said restoring force is stored.
- 33. The cartridge according to claim 24, wherein said cartridge includes a driving force receiving portion for receiving a driving force unsealing said seal member, from an operative member provided in said image forming apparatus main body, when unsealing of said seal member is started.
- 34. The cartridge according to claim 33, wherein said driving force receiving portion receives the driving force unsealing said seal member, from said operative member, from the start of unsealing of said seal member until before the unsealing is complete.
- 35. The cartridge according to claim 33, wherein interlocked with the operation for installing said cartridge in said image forming apparatus main body, said driving force receiving portion receives the driving force unsealing said seal member from said operative member.
- 36. The cartridge according to claim 33, wherein interlocked with an operation for closing a main body cover provided in said image forming apparatus main body, said driving force receiving portion receives the driving force unsealing said seal member from said operative member.
- 37. The cartridge according to claim 33, wherein said operative member is a rack, and said driving force receiving portion is a gear meshing with said rack.
- 38. The cartridge according to claim 33, wherein said operative member is a cam follower, and wherein said driving force receiving portion is a cam engaging with said cam follower.
- 39. The cartridge according to claim 24, wherein said cartridge includes a reduction means for reducing the difference between a load applied to said constant-load spring at the start of unsealing of said seal member and a load subsequently applied in unsealing an intermediate portion of said seal member.
- 40. The cartridge according to claim 39, wherein said reduction means has load applying means for applying a load to said constant-load spring separately from the force for unsealing said seal member when unsealing said intermediate portion of said seal member.
- 41. The cartridge according to claim 40, wherein said cartridge has a rotatable winding member for winding up said seal member to unseal said seal member, said drive source applies the unsealing force to said seal member via said winding member, and said load applying means applies a load to said winding member.
- 42. The cartridge according to claim 40, wherein the greater a speed at which said seal member is unsealed, the greater said load applied by said load applying means.
- 43. The cartridge according to claim 42, wherein said load applying means is a damper.
- 44. The cartridge according to claim 42, wherein said load applying means is an oil damper.
- 45. A cartridge detachably attachable to an image forming apparatus main body comprising:a developer bearing member for bearing a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer container for supplying the developer toward said developer bearing member, said developer container including a container main body having an opening through which the developer is supplied and a seal member for unsealably sealing said opening; and a drive source for applying a force for unsealing said seal member, said drive source including an elastic member to apply said unsealing force using a restoring force of said elastic member, wherein said developer container has holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored, wherein when said developer container is installed in an image forming apparatus main body, a releasing member provided in said apparatus main body releases the holding of said holding means in the state where said restoring force is stored, and wherein interlocked with an operation for closing a main body cover provided in said apparatus main body, said releasing member releases the holding of said holding means in the state where said restoring force is stored.
- 46. A cartridge detachably attachable to an image forming apparatus main body comprising:a developer bearing member for bearing a developer to develop an electrostatic image formed on an image bearing member with the developer; a developer container for supplying the developer toward said developer bearing member, said developer container including a container main body having an opening through which the developer is supplied and a seal member for unsealably sealing said opening; and a drive source for applying a force for unsealing said seal member, said drive source including an elastic member to apply said unsealing force using a restoring force of said elastic member, wherein said developer container has holding means holding in a state where the restoring force of said elastic member for applying the unsealing force unsealing said seal member is stored, wherein said cartridge includes support means provided outside said container main body to support said holding means, and said holding means is covered by said support means.
- 47. The cartridge according to any one of claims 24 to 44, further comprising said image bearing member.
- 48. The cartridge according to claim 47, wherein said image bearing member is a photosensitive member.
Priority Claims (4)
Number |
Date |
Country |
Kind |
11-039620 |
Feb 1999 |
JP |
|
11-039622 |
Feb 1999 |
JP |
|
11-136878 |
May 1999 |
JP |
|
2000-036993 |
Feb 2000 |
JP |
|
US Referenced Citations (37)
Foreign Referenced Citations (3)
Number |
Date |
Country |
62-127876 |
Jun 1987 |
JP |
62-110954 U |
Jul 1987 |
JP |
1-193872 |
Aug 1989 |
JP |