Electrophotography – Image formation – Development
Reexamination Certificate
2001-10-29
2003-09-23
Ngo, Hoang (Department: 2852)
Electrophotography
Image formation
Development
C399S111000, C399S119000, C222SDIG001
Reexamination Certificate
active
06625413
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electrophotographic image forming apparatus, and a developing device and a process cartridge for use therein.
The electrophotographic image forming apparatus forms an image on a recording medium by the use of the electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include an electrophotographic copier, an electrophotographic printer (such as a laser beam printer or an LED printer), a facsimile apparatus and a word processor.
Also, the process cartridge may be a cartridge into which charging means, developing means or cleaning means and an electrophotographic photosensitive drum are integrally incorporated, and which is made detachably mountable to the main body of the electrophotographic image forming apparatus. Alternatively, the process cartridge may be a cartridge into which at least one of charging means, developing means and cleaning means and an electrophotographic photosensitive drum are integrally incorporated, and which is made detachably mountable to the main body of the electrophotographic image forming apparatus. Further alternatively, the process cartridge may be a cartridge into which at least developing means and an electrophotographic photosensitive drum are integrally incorporated, and which is made detachably mountable to the main body of the electrophotographic image forming apparatus.
2. Description of the Related Art
In an electrophotographic image forming apparatus using the electrophotographic image forming process, there is adopted a process cartridge system in which an electrophotographic photosensitive member and process means for acting on the electrophotographic photosensitive member are integrally made into a cartridge which is made detachably mountable to the main body of the electrophotographic image forming apparatus. According to the process cartridge system, the maintenance of the apparatus can be done by a user himself without resorting a serviceman and therefore, the operability of the apparatus can be markedly improved. Therefore, the process cartridge system is widely used in electrophotographic image forming apparatuses.
As an example of such a process cartridge, there is known a developing device in which developing means which is one of the aforementioned process means is integrally made into a cartridge. The developing device sometimes adopts a construction in which a developing frame for supporting a developing sleeve or the like and a developer container for containing therein a toner which is a developer have their respective joint portions abutting against each other and ultrasonically welded together.
FIGS. 2
,
3
and
4
of the accompanying drawings show an example of a conventional developing device.
FIG. 2
is a longitudinal cross-sectional view showing the developing device as it is divided into a developing frame
52
and a developer container
51
.
FIG. 3
is a view of the developing frame
52
as it is seen from the developer container
51
side (from the direction of arrow III in FIG.
2
), and
FIG. 4
is a view of the developer container
51
as it is seen from the developing frame
52
side (from the direction of arrow IV in FIG.
2
).
As shown in
FIG. 4
, the joint portion of the developer container
51
to the developing frame
52
is provided with an opening portion
51
a
for feeding the toner from the developer container
51
to the developing frame
52
therethrough. The opening portion
51
a
, as shown in
FIG. 4
, is of a rectangular shape long in the left to right direction when the developer container
51
is seen from the developing frame
52
side. The opening portion
51
a
is provided with a toner seal member
53
having the surroundings of the opening portion
51
a
welded thereto so as to cover the opening portion
51
a
. The toner seal member
53
is torn before the use of the developing device and becomes capable of feeding the toner from the developer container
51
into the developing frame
52
.
On the other hand, as shown in
FIG. 3
, the developing frame
52
is provided with an opening portion
52
a
for supplying the toner fed out from the developer container
51
to a developing sleeve therethrough. The opening portion
52
a
is provided in opposed relationship with the opening portion
51
a
of the developer container
51
, and is substantially equal in size to the opening portion
51
a
of the developer container
51
.
As shown in
FIG. 3
, welding ribs
52
b
and
52
c
ultrasonically welded to the developer container
51
are provided in the respective vicinities of the upper and lower end portions of the developing frame
52
. The two welding ribs
52
b
and
52
c
are straight and are disposed substantially parallel to each other along the lengthwise direction of the opening portion
52
a
. Convex bosses
52
d
and
52
e
for positioning the developing frame
52
relative to the developer container
51
are provided on the lengthwisely opposite end portions of the upper welded rib
52
b
. Also, in order to prevent the leakage of the toner from between the developing frame
52
and the developer container
51
, seal members
55
and
56
formed of elastomeric foam are attached to the lengthwisely opposite end portions of the developing frame
52
.
On the other hand, as shown in
FIG. 4
, the developer container
51
is formed with welding grooves
51
b
and
51
c
at locations opposed to the welded ribs
52
b
and
52
c
of the developing frame
52
. The two welding grooves
51
b
and
51
c
are straight, and are disposed substantially parallel to each other along the lengthwise direction of the opening portion
51
a
. Positioning holes
51
d
and
51
e
fitted onto the bosses
52
d
and
52
e
, respectively, provided on the developing frame
52
are formed in the lengthwisely opposite end portions of the upper welding groove
51
b.
The developing frame
52
and the developer container
51
are positioned relative to each other by the bosses
52
d
,
52
e
and the positioning holes
51
d
,
51
e
being fitted together, and thereafter as shown in
FIG. 2
, ultrasonic vibration is applied thereto while the backs
52
f
and
52
g
of the surfaces on which the welding ribs
52
b
and
52
c
of the developing frame
52
are provided and the backs of the surfaces in which the welding grooves
51
b
and
51
c
of the developer container
51
are provided are pressed, whereby the welding ribs
52
b
and
52
c
are melted and welded to the welding grooves
51
b
and
51
c
, respectively, of the developer container
51
.
In the above-described conventional construction, however, if the welding condition is too strong during ultrasonic welding, the unevenness of the melting of the welding ribs increases and therefore, the developing frame becomes liable to be deformed. This has led to the possibility that the positional accuracy of parts attached to the developing frame may be reduced or the positional accuracy of the developing device and the image forming apparatus may be reduced, whereby the quality of printing may be reduced. Also, by making the energy applied during ultrasonic welding small in order to avoid such possibility, there have been posed the problem that the strength of welding is reduced or the setting of the welding condition becomes difficult, and the problem that the cost for raising the accuracy of parts is increased.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a developing device, a process cartridge and an electrophotographic image forming apparatus provided with a frame structure having sufficient welding strength.
It is another object of the present invention to provide a developing device, a process cartridge and an electrophotographic image forming apparatus provided with a construction suffering little from frame deformation during ultrasonic welding.
It is another object of the present invention to provide a developing device, a process cartridge and an electrophotographic image forming apparatus provide
Karakama Toshiyuki
Oguma Toru
Watanabe Kazushi
Yokoi Akiyoshi
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Ngo Hoang
LandOfFree
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