Information
-
Patent Grant
-
6810221
-
Patent Number
6,810,221
-
Date Filed
Thursday, April 24, 200321 years ago
-
Date Issued
Tuesday, October 26, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Grimley; Arthur T.
- Gleitz; Ryan
Agents
-
CPC
-
US Classifications
Field of Search
US
- 399 50
- 399 90
- 399 115
- 399 119
- 399 121
- 399 123
- 399 227
- 399 279
- 399 286
- 399 313
-
International Classifications
-
Abstract
A conductive isolation member for electrophotography components is disclosed. In one embodiment, a cartridge for use in an image forming device includes a photosensitive drum, an electrophotography component, and a conductive isolation member electrically connected to the electrophotography component to permit discharge of static charge on the electrophotography component upon removal of the conductive isolation member.
Description
BACKGROUND
Current image-forming devices exist in a variety of different configurations. Examples of current image-forming devices include printers, copiers, multifunction products, and the like.
Conventional image-forming devices may form an image by applying toner to a medium such as paper and fuse the toner onto the paper. One known toner generally comprises a mix of polymers, magnetite, charging agents, flow agents, and pigments or dyes. The toner is typically supplied from a removable cartridge.
Some conventional image-forming devices generally create an image upon a medium such as paper by initially creating a uniform negative charge on the surface of a photosensitive drum. This photosensitive drum is often referred to as an organic photoconductor (OPC) drum. A latent image is then formed on the photosensitive drum by modulating laser beams or other light on the photosensitive drum. The latent image on the photosensitive drum is changed to a visual image by the toner that is itself charged and is applied by a developer roller. The visual image created by the toner on the photosensitive drum is transferred to the medium by a transfer charging roller. Thereafter, the transferred toner is fused with heat and pressure to form a permanent image on the medium.
Electrophotography components that contact the photosensitive drum can develop a static electrical charge. An example of an electrophotography component that may contact the photosensitive drum is a primary charge roller. This static electrical charge may cause plus charge memory, also referred to as rubbed memory, on the photosensitive drum when the electrophotography component having the static electrical charge contacts the photosensitive drum. Additional background details are described in U.S. Pat. No. 5,666,608, the disclosure of which is hereby incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic illustration of an image forming device including a main assembly and a cartridge.
FIG. 2
is a sectional view schematically illustrating a cartridge having a conductive isolation member in accordance with an example embodiment of the present invention.
FIG. 3
is a sectional view schematically illustrating a cartridge having a conductive isolation member in accordance with another example embodiment of the present invention.
FIG. 4
is a sectional view schematically illustrating a cartridge having a conductive isolation member removed in accordance with another example embodiment of the present invention.
FIG. 5
is a sectional view schematically illustrating a cartridge having a conductive isolation member in accordance with another example embodiment of the present invention.
FIG. 6
is a sectional view schematically illustrating a cartridge having conductive isolation members in accordance with another example embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1
schematically illustrates an example embodiment of an image forming system or device
10
, which generally includes a cartridge
12
and a main assembly
14
. The cartridge
12
is configured to be releasably coupled to main assembly
14
in a conventional manner. The cartridge
12
generally supplies toner for forming images. In the particular embodiment illustrated, the cartridge
12
additionally includes components for transferring toner to a print media, such as paper
88
(e.g., FIG.
2
). The cartridge
12
generally includes supply hopper
20
, supply roller
24
, developer roller
26
, blade
28
, photosensitive drum
30
, charging roller
32
, cleaner blade
34
, and memory
36
.
Supply hopper
20
, which may comprise one or more chambers, supplies toner (e.g.,
FIG. 2
) to developer roller
26
. For purposes of this disclosure, the term “toner” means any pigment or dye containing material used for forming an image on a medium, such as polymer, paper and the like. Toner is typically electrically chargeable. In one embodiment, the toner includes a mix of dye or pigment impregnated plastic, magnitite, various conventionally known electrical charging agents that enhance the ability of the toner to take on an electrical charge and flow agents. In alternative embodiments, the toner utilized by device
10
may comprise other conventionally known or future developed toners that are capable of being electrically charged to a degree sufficient so as to enable the toner to be used by device
10
to form an image upon a print medium. Although the cartridge
12
is illustrated as including such components as supply roller
24
, developer roller
26
, blade
28
, photosensitive drum
30
, charging roller
32
and cleaner blade
34
, these components may be omitted in alternative embodiments. For example, in some applications, main assembly
14
may include photosensitive drum
30
in lieu of photosensitive drum
30
being provided as part of cartridge
12
. Also, as another example, in some applications, the supply roller
24
may be omitted.
Supply roller
24
, developer roller
26
and blade
28
are each conventionally known. Supply roller
24
supplies toner to developer roller
26
, which, in turn, supplies toner to photosensitive drum
30
. Blade
28
removes excess toner from developer roller
26
. In the particular embodiment illustrated, each of rollers
24
and
26
and blade
28
are electrically charged so as to apply charge to the toner. With such charging, the toner attains a negative charge. The charged particles upon developer roller
26
are then transferred to an electrically charged photosensitive drum
30
.
Although rollers
24
and
26
and blade
28
are illustrated and described as being electrically charged so as to apply charge to the toner, less than all of these components, as well as additional or alternative components, may alternatively be used to apply electrical charge to the toner.
Photosensitive drum
30
, charging roller
32
and blade
34
are each conventionally known. Charging roller
32
applies a generally uniform negative charge on the surface of drum
30
which is generally rotatably driven in a clockwise direction as seen in FIG.
1
. Prior to receiving toner from developer roller
26
, light is projected upon the surface of the drum to discharge the negative potential along the surface of the photosensitive drum where the light strikes the surface. As a result, a latent electrostatic image is created on drum
30
. As will be described in greater detail hereafter, this light may be in the form of a laser beam
81
(e.g., FIG.
2
).
Once the latent electrostatic image is formed on drum
30
, the charged particles from developer roller
26
are transferred to drum
30
in the form of the visible image. This visible image is then transferred to a medium such as paper. Excess or residue toner on the surface of drum
30
is removed by blade
34
.
Main assembly
14
is generally configured to cooperate with cartridge
12
so as to form an image upon a medium such as paper. Main assembly
14
generally includes image writing system
50
, media transport
52
, transfer charging roller
54
, static charge eliminator
56
, fuser
58
, and a controller generally including formatter board
60
, engine controller board
62
, and memory controller
64
. Image writer
50
is generally configured to apply light or other waves to photosensitive drum
30
, such as in the form of a laser, to write a latent electrostatic image upon the surface of drum
30
.
Media transport
52
is conventionally known and generally comprises that portion of main assembly
14
which is configured to supply and transport a medium, such as paper, upon which an image is to be formed. In the particular embodiment illustrated, media transport
52
includes various rollers
68
and a belt
70
configured to transport media from a paper supply (not shown) between photosensitive drum
30
and transfer charging roller
54
and further to fuser
58
. Various other conventionally known or future developed media transfer mechanisms may be employed in lieu of the one schematically shown.
Transfer charging roller
54
and static charge eliminator
56
are each conventionally known. Transfer charging roller
54
facilitates the transfer of toner from drum
30
to the media in a conventionally known manner. Thereafter, static charge upon the media is removed by static charge eliminator
56
in a conventionally known manner. Once the toner has been transferred to the media, media transport
52
transfers the media to fuser
58
.
Fuser
58
is configured to fuse the toner to the media to form a permanent image on the media. In the particular embodiment illustrated, fuser
58
fuses the media with heat and pressure. Fuser
58
, which is conventionally known, generally includes a pressure roller
72
and a film unit
74
. After the image has been permanently fused to the media by fuser
58
, the media is expelled by main assembly
14
.
The controller including formatter board
60
, engine controller board
62
and memory controller
64
generally controls the operation of the remainder of cartridge
12
and main assembly
14
. In particular, formatter board
60
sends a print signal and a video signal to the engine controller board
62
. In response, the engine controller board
62
drives a main motor (not shown) to rotate photosensitive drum
30
, charging roller
32
, supply roller
24
, developing roller
26
, various belts and rollers of media transport
52
, transfer charging roller and the pressure roller, amongst others. In response to signals from the engine controller board based upon the video signals, image writing system
50
modulates laser beams to create a latent image on the photosensitive drum.
Memory controller
64
generally comprises a control circuit configured to write data to memory
36
and read data from memory
36
of cartridge
12
. Memory controller
64
records such data on memory
36
such as the number of copies or amount of media printed upon using toner from cartridge
12
, job length, media size, mode, coverage, fuser and other historical data regarding the image formation using cartridge
12
. Controller
64
further reads such recorded information from memory
36
and based on such information, cooperates with engine controller board
62
to generate control signals.
In the embodiment shown in
FIG. 1
, certain electrophotography components, such as the charging roller
32
, the developer roller
26
, and blade
34
may contact, or come into close proximity with, the photosensitive drum
30
. Before first operation of the cartridge
12
, such as during shipping, static charge may develop on these electrophotography components. If this static charge is conducted to the photosensitive drum
30
, the photosensitive drum
30
may develop a region on the outer surface thereof that has a different charge than other regions of the outer surface of the photosensitive drum
30
. This charge differential on the outer surface of the photosensitive drum
30
may adversely affect print quality, particularly if the charge differential is located in a print region of the photosensitive drum
30
.
A conductive isolation member
73
(e.g.,
FIG. 2
) is removably positioned in electrical contact with an outer surface of such electrophotography components. Prior to the first use of the cartridge
12
, a user removes the conductive isolation member
73
from the cartridge
12
by manually grasping the cartridge, such as with the user's hand, and pulling, or otherwise removing, the conductive isolation member
73
from the cartridge
12
. When the user grasps the conductive isolation member
73
, the electrophotography component, the conductive isolation member
73
, and the user form an electrical circuit for discharging static charge on the electrophotography component. Thus, the conductive isolation member
73
drains static charge that may have formed on the electrophotography component, such as the charging roller
32
, during removal of the conductive isolation member
73
. The static charge dissipates through the user's hand upon removal of the conductive isolation member
73
, since the conductive isolation member
73
is electrically coupled to the electrophotography component when the user grasps the conductive isolation member
73
.
FIG. 2
illustrates an example embodiment of a cartridge
12
. For ease of illustration, the exterior enclosure or housing of cartridge
12
is not shown. The exact configuration of the exterior housing or enclosure of cartridge
12
may vary depending upon the size and configuration of the various internal components of cartridge
12
as well as the interfacing relationship between cartridge
12
and the main assembly
14
(FIG.
1
).
The cartridge
12
includes a supply hopper
20
, which may have toner
74
disposed therein. Stirring blade
76
is also positioned within the supply hopper
20
and is operative to stir the toner
74
. A developer sealing blade
76
helps maintain the toner
74
within the supply hopper
20
and substantially prevents toner
73
from passing from the supply hopper
20
between the developer sealing blade
76
and the development roller
26
. The blade
34
wipes excess toner
78
from the photosensitive drum
30
. Waste toner chamber stores the excess toner
78
.
In the illustrated embodiment, the charging roller
32
may be biased toward the photosensitive drum
30
, such as by a spring
82
or other suitable biasing member or mechanism. The conductive isolation member
73
is positioned in electrical contact with the charging roller
32
. Thus, upon user manual removal of the conductive isolation member
73
, static electric charge on the charging roller
32
is dissipated by conducting from the conductive isolation member
73
, through the conductive isolation member
73
to the user. Hence, after removal of the conductive isolation member
73
from the cartridge
12
, the charging roller
32
is substantially free from static electrical charge, thereby reducing or eliminating the potential for damage to the photosensitive drum
30
by static electrical charge on the charging roller
32
.
As shown, the conductive isolation member
73
is formed of a suitable conductive material, such as metal. The shape of the conductive isolation member
73
may vary. For example, the conductive isolation member
73
may comprise, but is not limited to, an elongated sheet of conductive material, a conductive tape, a conductive pin.
Hence, pursuant to some embodiments, the conductive isolation member
73
is tightly disposed between the charging roller
32
and the photosensitive drum
30
by a compression fit so that the biasing force of the spring
82
maintains the conductive isolation member
73
. Upon removal of the conductive isolation member
73
the spring
82
moves the charging roller
32
into contact or close proximity to the photosensitive drum
30
(see, e.g., FIG.
4
). In some applications, the conductive isolation member
73
contacts the photosensitive drum
30
at a region outside of an imaging region thereof to further limit potential damage to the imaging region of the photosensitive drum
30
.
In another embodiment, the conductive isolation member
73
is adhered to the charging roller
32
and may or may not be disposed between the charging roller
32
and the photosensitive drum
30
as shown in FIG.
2
. The conductive isolation member
73
, in this embodiment may have an adhesive, such as an electrically conductive adhesive, thereon to facilitate adhering the conductive isolation member
73
to an electrophotography component, such as the charging roller
32
.
FIG. 3
illustrates another embodiment of the cartridge
12
. This embodiment is identical to that described above with reference to
FIG. 2
, except as follows. In the embodiment of
FIG. 3
, the conductive isolation member
73
includes a conductive material
90
on a non-conductive material
92
. As shown, the conductive material
90
is in electrical contact, or connection, with the charging roller
32
and the non-conductive material
92
contacts a surface of the photosensitive drum
30
. In this configuration, static charge on an electrophotography component, such as the charging roller
32
, may be discharged via the conductive material
90
while the non-conductive material
92
insulates the photosensitive drum
30
from the static charge.
FIG. 4
illustrates the cartridge
12
with the conductive isolation member
73
removed. As shown, with the conductive isolation member
73
removed from between the charging roller
32
and the photosensitive drum
30
, the biasing force of the spring
82
pushes the charging roller
32
into close proximity, or in contact with, the photosensitive drum
30
.
FIG. 5
illustrates another embodiment of the cartridge
12
. This embodiment is identical to that described above with reference to
FIG. 2
, except as follows. Pursuant to this embodiment, the conductive isolation member
73
is electrically coupled to a grounding member
95
, such as a metal chassis (not shown) of the main assembly
14
. In this embodiment, static electric charge on the charging roller
32
is discharged through the conductive isolation member
73
and to the grounding member
95
.
FIG. 6
illustrates another embodiment of the cartridge
12
. This embodiment is identical to that described above with reference to
FIG. 2
, except as follows. As shown in
FIG. 6
, multiple conductive isolation members may be electrically connected to multiple electrophotography components, respectively. In the example embodiment shown, conductive isolation members
73
A,
73
B are electrically connected to the developer roller
26
. The conductive isolation member
73
A is positioned between the blade
28
and the roller
26
. The conductive isolation member
73
B is positioned between the developer roller
26
and the photosensitive drum
30
. A conductive isolation member
73
C is shown as being electrically connected to the blade
34
and positioned between the blade
34
and the photosensitive drum
30
. The conductive isolation members
73
A,
73
B,
73
C may be electrically connected to respective electrophotography components by an adhesive, such as an electrically-conductive adhesive, by a compression fit or other suitable technique.
Hence,
FIG. 6
illustrates a cartridge
12
having conductive isolation members
73
,
73
A,
73
B, and
73
C. In one embodiment, one or more of the conductive isolation members shown in
FIG. 6
are configured identical to the conductive isolation member
73
shown in FIG.
3
and described above with reference to FIG.
3
.
Accordingly, embodiments of the present invention permit static charge on an electrophotography component to be discharged through a conductive isolation member electrically connected thereto. In one embodiment, static charge conducts from the electrophotography component, through the conductive isolation member to a user upon removal of the conductive isolation member from the cartridge.
While the present invention has been particularly shown and described with reference to the foregoing embodiments, those skilled in the art will understand that variations may be made therein without departing from the spirit and scope of the invention as defined in the following claims. This description of the invention should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. The foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application. Where the claims recite “a” or “a first” element of the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
Claims
- 1. A cartridge for use in an image forming device, the cartridge comprising:a photosensitive drum; an electrophotography component having an electrically conductive surface; an electrically conductive isolation member removably disposed between the photosensitive drum and electrically connected to the electrically conductive surface of the electrophotography component for draining charge on the electrophotography component upon removal of the electrically conductive isolation member from the cartridge.
- 2. The cartridge according to claim 1, wherein the isolation member comprises a conductive material on a non-conductive material.
- 3. The cartridge according to claim 1, wherein the electrophotography component comprises a charge roller configured to apply a substantially uniform charge on a surface of the photosensitive drum.
- 4. The cartridge according to claim 1, wherein the conductive isolation member is disposed between the photosensitive drum and the electrophotography component by a compression fit.
- 5. The cartridge according to claim 1, wherein the conductive isolation member is adhered to the electrophotography component by an adhesive.
- 6. The cartridge according to claim 1, wherein the electrophotography component comprises a transfer roller configured to apply a charge to print media.
- 7. The cartridge according to claim 1, wherein the electrophotography component comprises a development roller configured to supply toner to the photosensitive drum.
- 8. The cartridge according to claim 1, wherein the electrophotography component comprises a cleaning blade configured remove toner from the photosensitive drum.
- 9. A laser printer device comprising the cartridge according to claim 1.
- 10. A method for draining charge from an electrophotography component, the method comprising:interposing a conductive member between an electrophotography component and a photosensitive drum to maintain the electrophotography component and the photosensitive drum in spaced relation to each other; manually grasping the conductive member to permit dissipation of charge formed on the electrophotography component through the conductive member.
- 11. The method according to claim 10, wherein the manually grasping comprises a human touching the conductive member such that an electrical circuit is formed between the electrophotography component and the human.
- 12. The method according to claim 10, wherein the conductive member comprises a conductive material on a non-conductive material, the conductive material being in electrical contact with the electrophotography component and the non-conductive material being in contact with the photosensitive drum.
- 13. The method according to claim 10, wherein the electrophotography component comprises a charge roller configured to apply a substantially uniform charge on a surface of the photosensitive drum.
- 14. The method according to claim 10, wherein the conductive member is interposed between the photosensitive drum and the electrophotography component by a compression fit.
- 15. The method according to claim 10, wherein the electrophotography component comprises a transfer roller configured to apply a charge to print media.
- 16. The method according to claim 10, wherein the electrophotography component comprises a development roller configured to supply toner to the photosensitive drum.
- 17. The method according to claim 10, wherein the electrophotography component comprises a cleaning blade configured remove toner from the photosensitive drum.
- 18. A cartridge, comprising:a photosensitive drum; a charge roller configured to apply a substantially uniform charge on a surface of the photosensitive drum; a conductive isolation member electrically connected to and detachably coupled to the charge roller for draining charge on the charge roller upon detachment of the conductive isolation member from the charge roller.
- 19. The cartridge of claim 18, wherein the conductive isolation member comprises a conductive tape having an adhesive thereon.
- 20. A cartridge, comprising:a photosensitive drum; a charge roller configured to apply a substantially uniform charge on a surface of the photosensitive drum; conductive tape electrically connected to and adhered to the charge roller for draining charge on the charge roller upon detachment of a conductive charge roller.
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2002258581 |
Sep 2002 |
JP |