Title: Toner cartridge having a toner agitator and a reciprocally moving member coupled to the agitator, and an image forming apparatus
Abstract: A toner cartridge has a toner-agitating member that agitates the toner to be supplied to a developing unit. The toner cartridge has at least a part of a detecting mechanism that transmits the motion of the agitating member to detect an amount of the remaining toner in the toner cartridge. The detecting mechanism has a sensor rod. The sensor rod has one end that rotatably engages the agitating member and the other end to which a detector is attached. At least a part of the motion-transmitting section is made of a material that when the part receives a pressure greater than a predetermined value, the part absorbs the pressure.
Patent Number: 6,892,036 Issued on 05/10/2005 to Ito
| Inventors:
|
Ito; Junichi (Tokyo, JP)
|
| Assignee:
|
Oki Data Corporation (Tokyo, JP)
|
| Appl. No.:
|
212123 |
| Filed:
|
August 6, 2002 |
Foreign Application Priority Data
| Aug 07, 2001[JP] | 2001-239001 |
| Current U.S. Class: |
399/27; 399/254; 399/263 |
| Intern'l Class: |
G03G 015/08 |
| Field of Search: |
399/262,263,27,61,63,254
222/DIG. 1
118/692,694
|
References Cited [Referenced By]
U.S. Patent Documents
| 4592642 | Jun., 1986 | Imaizumi et al.
| |
| 5287151 | Feb., 1994 | Sugiyama.
| |
| 5790917 | Aug., 1998 | Takura et al.
| |
| 5923918 | Jul., 1999 | Nakagawa et al.
| |
| 6100601 | Aug., 2000 | Baker et al.
| |
| 6415126 | Jul., 2002 | Kaneshige et al.
| |
| 6510291 | Jan., 2003 | Campbell et al.
| |
| 6546213 | Apr., 2003 | Ito et al.
| |
| Foreign Patent Documents |
| 11119537 | Apr., 1999 | JP.
| |
Primary Examiner: Beatty; Robert
Attorney, Agent or Firm: Rabin & Berdo, P.C.
Claims
1. A toner cartridge that supplies toner to a developing unit for forming a toner
image, the toner cartridge comprising:
a chamber that holds the toner therein;
an agitator that rotates to agitate the toner in the chamber; and
a reciprocally moving member that extends generally in a longitudinal direction
and is operatively coupled to the agitator, wherein the agitator rotates relative
to the reciprocally moving member to cause the reciprocally moving member to perform
a reciprocating motion substantially in the longitudinal direction;
wherein at least a part of said reciprocally moving member is made of a material
such that when the part receives a pressure greater than a predetermined value,
the part absorbs the pressure.
2. The toner cartridge according to claim 1, wherein the part of said reciprocally
moving member is in contact with the toner.
3. The toner cartridge according to claim 1, wherein said reciprocally moving
member is a part of a remaining toner-detecting mechanism that detects an amount
of toner remaining in said chamber.
4. The toner cartridge according to claim 3, wherein the remaining toner-detecting
mechanism includes said agitator that agitates the toner in the toner cartridge;
wherein said reciprocally moving member has a first end rotatably engaging said
agitator and a second end having a detector.
5. The toner cartridge according to claim 4, wherein the detector is made of
a magnetic body.
6. The toner cartridge according to claim 4, wherein the detector is made of
a permanent magnet.
7. The toner cartridge according to claim 4, wherein said remaining toner-detecting
mechanism includes a guide formed on an inner wall of said chamber;
wherein the guide receives the second end of said reciprocally moving member
in such a way that the second end can slide on the guide.
8. The toner cartridge according to claim 7, wherein the guide has a hole formed
therein and a cavity portion is defined between the guide and the reciprocally
moving member, the cavity portion communicating with the hole.
9. The toner cartridge according to claim 1, wherein said agitator includes a
first crank and a second crank, the first crank agitating the toner in the toner chamber;
wherein the agitator is rotatably supported at its one end portion by a side
wall of the toner chamber, and the second crank is coupled to the reciprocally
moving member in such a way that the second crank is rotatable relative to the
first end of the reciprocally moving member to cause said reciprocally moving member
to perform the reciprocating motion.
10. The toner cartridge according to claim 1, wherein the material is a flexible material.
11. The toner cartridge according to claim 10, wherein the flexible material
is a metal material.
12. The toner cartridge according to claim 11, wherein the reciprocally moving
member has a diameter in the range of 0.4 to 0.8 mm.
13. An image forming apparatus to which a print process cartridge is attachable,
the print process cartridge including a developing unit that forms a toner image,
the image forming apparatus comprising:
a mounting section to which a the print process cartridge is removably attached,
the print process cartridge removably holding a toner cartridge that has a toner
chamber, an agitator that rotates to agitate toner in the toner chamber, and a
reciprocally moving member that extends generally in a longitudinal direction and
is operatively coupled to the agitator, wherein the agitator rotates relative to
the reciprocally moving member to cause the reciprocally moving member to perform
a reciprocating motion substantially in the longitudinal direction, and at least
a part of the reciprocally moving member being made of a material that absorbs
a pressure greater than a predetermined value; and
a drive source that drives the agitator from outside of the toner cartridge.
14. The image forming apparatus according to claim 13, further comprising a sensor
mechanism that detects the reciprocating motion of said reciprocally moving member
to detect an amount of remaining toner in the toner chamber.
15. The image forming apparatus according to claim 14, wherein the reciprocally
moving member has a first end that engages the agitator and a second end that is
connected to a detection member.
16. The image forming apparatus according to claim 15, wherein the sensor mechanism
includes a sensor lever that cooperates with the detection member in such a way
that the sensor lever and the detection member attract each other and a sensor
is switched between an ON state and an OFF state by the sensor lever.
17. The image forming apparatus according to claim 16, wherein the sensor lever includes;
a first lever pivotally supported on a first pivot shaft and having one end portion
that causes the sensor to switch between the ON state and the OFF state; and
a second lever pivotally coupled to another end of said first lever through a
second pivot shaft, and attracting the detection member provided on the reciprocally
moving member;
wherein when the second lever receives a force in an opposite direction to an
attraction force of the detection member, the second lever pivots about the second
pivot shaft relative to the first lever.
18. The image forming apparatus according to claim 16, wherein the sensor lever
includes a first lever and a second lever;
wherein when the second lever receives a first force equal to or less than a
certain value, the first lever and the second lever move together to cause the
sensor to normally operate;
wherein when the second lever receives a second force greater than the certain
value, the second lever displaces with respect to the first lever in such a direction
as to move away from the second force.
19. A print process cartridge having a developing unit that forms a toner image,
the print process cartridge comprising:
a mounting section to which a toner cartridge is removably attached, the toner
cartridge removably having a toner chamber, an agitator that rotates to agitate
toner in the toner chamber, and a reciprocally moving member that extends generally
in a longitudinal direction, and is operatively coupled to the agitator, wherein
the agitator rotates relative to the reciprocally moving member to cause the reciprocally
moving member to perform a reciprocating motion substantially in the longitudinal
direction, and at least a part of the reciprocally moving member being made of
a material that absorbs a pressure greater than a predetermined value; and
a drive force-transmitting section that transmits a drive force to the motion
transmitting section.
20. A toner cartridge that supplies toner to a developing unit for forming a
toner image, the toner cartridge comprising:
a chamber that holds the toner therein:
an agitator that rotates to agitate the toner in said chamber;
a reciprocally moving member that is operatively coupled to the agitator, wherein
the agitator rotates relative to the reciprocally moving member to cause the reciprocally
moving member to perform a reciprocating motion; and
a guide member provided on an inner wall of said chamber and which receives one
end of the reciprocally moving member so that said reciprocally moving member slidably
moves in said guide member;
wherein at least a part of said reciprocally moving member is made of a material,
such that when the part receives a pressure greater than a predetermined value,
the part absorbs the pressure to yieldably resiliently deform so that said agitator
continues to rotate.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus such as an electrophotographic
recording apparatus and a copying machine, a print process cartridge that is removably
attached to an image forming apparatus, and a toner cartridge that is removably
attached to a print process cartridge.
2. Description of the Related Art
One conventional electrophotographic recording apparatus is an electrophotography
color image recording apparatus and incorporates a print medium transporting member
and a plurality of image-forming sections. The print medium-transporting member
transports a print medium to the image forming sections. The image forming sections
are disposed in a direction in which the print medium is transported. The image-forming
sections form toner images of corresponding colors. Each of the image forming sections
has a print process cartridge, an exposing unit, and a transfer unit. The transfer
unit transfers a toner image formed in the print process cartridge. The print process
cartridge is removably attached to the image forming section. The print process
cartridge includes a charging unit, a photoconductor, a developing unit, a cleaning
unit, a toner cartridge, and a drive force-transmitting section. The drive force-transmitting
section transmits a drive force for driving the charging unit, photoconductor,
and developing unit. The charging unit charges the photoconductor. The exposing
unit illuminates the charged surface of the photoconductor. Then, the exposing
unit forms an electrostatic latent image on the surface of the photoconductor in
accordance with print data. The developing unit applies toner to the electrostatic
latent image on the photoconductor to develop the latent image into a toner image.
The cleaning unit scratches off the toner that has failed to be transferred and
remained on the photoconductor. The toner cartridge supplies toner to the developing
unit. The toner cartridge is removably attached to the print process cartridge.
The developing unit includes a developing roller and a toner-supplying roller.
The developing roller is in pressure contact with the surface of the photoconductor.
The developing roller applies the toner to the electrostatic latent image on the
photoconductor to develop the electrostatic latent image into a toner image.
The toner cartridge includes an opening, an agitator, and a remaining-toner detecting
mechanism, and holds toner therein. The toner is supplied through the opening from
the toner cartridge to the toner supplying roller and developing roller. The toner-supplying
roller supplies the toner to the developing roller. The agitator agitates the toner
before supplying the toner to the developing unit. The agitator has an agitating
shaft. The agitating shaft is linked to a remaining toner detecting mechanism.
The remaining toner detecting mechanism detects an amount of the remaining toner
from the operation of the agitator. A drive source rotates at a predetermined speed.
The agitating shaft is supported by bearings. The agitating shaft rotates in such
a way that the agitating shaft can be connected to and disconnected from the drive
force transmitting section.
When the agitating shaft rotates, it is subject to a load of toner, which depends
on an amount of remaining amount of toner. The time required for the agitating
shaft to make one complete rotation depends on the load of toner. When the agitating
shaft passes its top dead center, the agitating shaft drops due to its own weight
toward the top surface of the pile of toner. When the amount of remaining toner
is large, the agitating shaft falls through a short distance before it lands on
the pile f toner. When the amount of remaining toner is small, the agitating shaft
falls through a long distance before it lands on the pile of toner. The toner remaining
detecting mechanism detects the amount of remaining toner by comparing the time
required for the drive source to make one complete rotation with the time required
for the agitating shaft to make one complete rotation.
A fine shaft is coupled to the agitating shaft and transmits the motion of the
agitating shaft. The guide section constraints the motion of the tip portion of
the sensor shaft to the reciprocating motion of the fine shaft. The toner cartridge
is stored and is subject to mechanical vibration during transportation. Toner may
be clumped in the toner cartridge due to mechanical vibration and long storage.
Therefore, printing may be performed when a lump of toner is in the path of the
tip portion of the sensor shaft. The toner cartridge allows the agitator to operate
when printing is performed. The fine shaft operates to follow the motion of the
agitator. The movement of the fine shaft is interfered with a lump of toner, so
that the fine shaft is subject to a load due to the lump of toner. The bearing
of the agitating shaft receives an increased load when the load on the fine shaft
increases. When a load is exerted on the fine shaft, the rod may be deformed and
sometimes may not regain its original shape. If the permanently deformed fine shaft
is operated, the fine shaft may collide with surroundings or its mounting members.
Due to collision of the fine shaft with mounting members and the surroundings
during the mounting operation, the fine shaft receives larger loads. The load on
the fine shaft is transmitted to the agitating shaft. The load of the agitating
shaft is transmitted to the drive source that drives the agitating shaft. Thus,
an increased load may prevent the drive source from driving the agitating shaft normally.
If the agitating shaft cannot rotate normally, it cannot agitate the clumped
toner
normally. If the toner is not normally agitated, the toner cartridge cannot supply
the toner normally to the developing unit. If a sufficient amount of toner is not
supplied to the developing unit, an electrostatic latent image cannot be developed
into a toner image normally. Because a toner image is no normally formed in the
print process cartridge, the image forming sections fail to conduct normal printing.
SUMMARY OF THE INVENTION
An object of the invention is to provide a toner cartridge in which even if a
load is exerted on the fine shaft and agitating shaft, a printing operation can
be performed normally.
Another object of the invention is to provide a print process cartridge to
which a toner cartridge can be removably attached, the toner cartridge being such
that even if a load is exerted on the fine shaft and agitating shaft, a printing
operation can be performed normally.
A still another object of the invention to provide an image forming section to
which a toner cartridge can be removably attached, the print process cartridge
being such that even if a load is exerted on the fine shaft and agitating shaft,
a printing operation can be performed normally.
In order to achieve the aforementioned objects, a toner cartridge according to
the present invention is of the following configuration.
A toner cartridge includes a toner chamber, a motion-transmitting section, and
at least a part of a remaining toner detecting mechanism. The toner chamber holds
toner therein which in turn is supplied to the developing unit. At least a part
of the motion transmitting section includes a member that when pressures greater
than a predetermined value are applied to the member, the member absorbs the applied pressure.
A print process cartridge according to the invention includes a drive force-transmitting
section that transmits a drive force from the drive source to the toner cartridge.
The charging unit charges a photoconductor. The exposing unit illuminates the surface
of the charged photoconductor. The exposing unit forms an electrostatic latent
image in accordance with print data. The developing unit develops the electrostatic
latent image with toner into a toner image. The cleaning section scratches residual
toner that has failed to be transferred and remained on the photoconductor. The
toner cartridge is removably attached to the print process cartridge.
In order to achieve the aforementioned object, an image forming section according
to the invention is of the following configuration. The image forming section includes
a print process cartridge, a transfer section, a medium-transporting member, and
a part of a remaining toner-detecting mechanism. The transfer section transfers
the toner image formed in the print process cartridge onto a print medium. The
remaining toner-detecting mechanism includes a detecting mechanism that detects
the operation of the fine shaft, the detecting mechanism being provided on the
main body of the image forming section.
Further scope of applicability of the present invention will become apparent
from the detailed description given hereinafter. However, it should be understood
that the detailed description and specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the invention will become
apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description
given hereinbelow and the accompanying drawings which are given by way of illustration
only, and thus are not limiting the present invention, and wherein:
FIG. 1 is a perspective view of a toner cartridge in FIG. 11 taken along line
I—I of FIG. 11;
FIG. 2 is an illustrative diagram of an electrophotographic color recording
apparatus according to a first embodiment;
FIG. 3 is a cross-sectional view of an image forming section;
FIG. 4 is a first exploded perspective view of the toner cartridge;
FIG. 5 is a second exploded perspective view of the toner cartridge;
FIG. 6 illustrates a waste toner chamber in detail;
FIG. 7 illustrates a fresh toner chamber in detail;
FIG. 8 illustrates a side plate in detail;
FIG. 9 illustrates the relation between an operating knob and an agitating shaft;
FIG. 10 illustrates a bearing member;
FIG. 11 is a fragmentary perspective view of the toner cartridge;
FIG. 12 is a fragmentary perspective view of a print process cartridge;
FIG. 13 is a control block diagram for detecting an amount of remaining toner
in the toner cartridge;
FIG. 14 is a first diagram, illustrating how the toner cartridge is attached
to the print process cartridge;
FIG. 15 is a second diagram, illustrating how the toner cartridge is attached
to the print process cartridge;
FIG. 16A is an illustrative diagram (A), illustrating a toner supplying operation
according to the present invention;
FIG. 16B is an illustrative diagram (B), illustrating a toner supplying operation
according to the present invention;
FIG. 17A illustrates the present invention when an amount of the remaining toner
is sufficient;
FIG. 17B illustrates the present invention when an amount of the remaining toner
is not sufficient;
FIG. 17C illustrates the present invention when the toner cartridge is empty
of toner;
FIG. 18A is an illustrative diagram (A), illustrating the operation of the agitating
shaft and the sensor;
FIG. 18B is an illustrative diagram (B), illustrating the operation of the agitating
shaft and the sensor;
FIG. 18C is an illustrative diagram (C), illustrating the operation of the agitating
shaft and the sensor;
FIG. 18D is an illustrative diagram (B), illustrating the ON/OFF conditions
at a toner LOW condition in which an amount of remaining toner is not sufficient;
FIG. 18E illustrates the ON/OFF conditions at a toner FULL condition in which
remaining toner is sufficient;
FIG. 19 is a perspective view of a sensor lever according to a second embodiment;
FIG. 20 illustrates a coupling portion of the lever in detail; and
FIG. 21 is a perspective view of the fine shaft according to a third embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described with reference to the
accompanying drawings. Like elements have been given like reference numerals throughout
the drawings.
First Embodiment
FIG. 2 is an illustrative diagram of an electrophotographic color recording
apparatus according to a first embodiment.
An electrophotographic recording apparatus
1 includes a medium-transporting
belt
4, drive rollers
2 and
3, and image forming sections
5-
8. The medium-transporting belt
4 extends in a direction
in which the medium is transported. The transporting belt
4 is mounted about
the drive rollers
2 and
3. The image forming sections
5-
8
are aligned along the medium-transporting belt
4. The image forming sections
5-
8 are of the same configuration and form yellow, magenta, cyan,
and black images. The image forming sections
5-
8 each include a print
process cartridge
16 and a transfer roller
9. The transfer rollers
9 are aligned along the medium-transporting belt
4. The electrophotographic
color recording apparatus has a cover
10. The cover
10 includes an
exposing unit
11, a sensor lever
14, and a sensor
15. The
sensor
15 takes the form of, for example, a photo sensor. The sensor lever
14 includes a permanent magnet
12 and a pivot shaft
13. The
permanent magnet
12 is fixedly mounted to a first end of the sensor lever
14. The pivot shaft
13 supports the sensor lever
14 thereon
such that the sensor lever
14 is rotatable. The pivot shaft
13 is
press-fitted into a bracket, not shown, provided on the cover
10. The sensor
15 is switched between ON and OFF states according to the movement of the
sensor lever
14.
FIG. 3 is a cross-sectional view of the image forming section.
An image forming section
5 includes a print process cartridge
16,
an exposing unit
11, and a transfer roller
9. The print process cartridge
16 is detachably mounted to the image forming section
5. The print
process cartridge
16 includes a toner cartridge
17, a photoconductive
drum
18, a charging roller
19, a developing unit
22, and the
toner cartridge
17 is detachably attached to the print process cartridge
16. An image to be printed is formed on the photoconductive drum
18.
The photoconductive drum
18 extends in a direction perpendicular to a direction
in which the medium is transported. The photoconductive drum
18 includes
a charging roller
19, an exposing unit
11, a developing roller
20,
a transfer roller
9, and cleaning blade
21, which are surrounding
the photoconductive drum
18. The charging roller
19 charges the surface
of the photoconductive drum
18 uniformly. The exposing unit
11 illuminates
the surface of the photoconductive drum
18 in accordance with print data.
When the surface of the photoconductive drum
18 is exposed to the light
from the exposing unit
11, an electrostatic latent image is formed on the
surface of the photoconductive drum
18. The developing roller
20
applies toner on the electrostatic latent image on the photoconductive drum
18
to form a toner image. The transfer roller
9 transfers the toner image onto
the print medium from the photoconductive drum
18. The print medium is transported
on the medium transporting belt
4. The cleaning blade
21 scratches
the residual toner that has failed to be transferred and remained on the photoconductive
drum
18. The developing unit
22 has the developing roller
20
and the toner-supplying roller
23. The toner-supplying roller
23
is in pressure contact with the developing roller
20.
The toner cartridge
17 has a fresh toner chamber and an opening
24
through which the toner is discharged. The toner is supplied to the developing
unit
22 through the opening
24. The toner is charged by the developing
roller
20 and toner supplying roller
23. The charged toner is supplied
to the developing roller. A blade
25 is in pressure contact with the developing
roller
20. The blade
25 makes a thin layer of toner on the developing
roller
20 as the developing roller
20 rotates.
FIG. 4 is a first exploded view of the toner cartridge of the embodiment.
FIG. 5 is a second exploded view of the toner cartridge of the embodiment.
FIG. 6 illustrates the details of the waste toner chamber.
FIG. 7 illustrates the details of the fresh toner chamber.
FIG. 8 illustrates the details of a side plate.
FIG. 9 illustrates the relationship between an operating knob and an agitating shaft.
FIG. 10 is a front view of a bearing portion.
The cartridge case
26 of the toner cartridge
17 has a body case
28. As shown in FIG. 4, the body case
28 is in one piece construction
with a side wall
27. The cartridge case
26 has a side plate
29.
The side plate
29 is fitted into the body case
28, thereby forming
another side wall. A cylindrical boss
30 is formed in the side wall
27.
The boss
30 couples a later described operating knob. The side wall
27
is formed with a toner-filling opening
31. A cap
31a is fitted
into the toner-filling opening
31. The cap
31a is desirably
made of a colorless transparent material or colorless translucent material, so
that the toner can be seen through the cap
31a. The body case
28
has fitting holes
32 formed in the circumferential portion of the body case
28. The side plate
29 has projections
45 that fit into the
fitting holes
32. When the side plate
29 and body case
28
are fitted together, the projections
45 fit into the fitting holes
32.
The cartridge case
26 has the fresh toner chamber
33 and the waste
toner chamber therein. The fresh toner chamber
33 holds fresh, unused toner
therein. The waste toner chamber
34 holds waste toner that has failed to
be transferred. The waste toner that has failed to be transferred is delivered
from a cleaning unit, not shown, to the toner cartridge. The fresh toner chamber
33 and waste toner chamber
34 are integrally constructed and partitioned
by an inner wall
35 of the body case
28.
The waste toner chamber
34 is located beside the fresh toner chamber
33
in the direction of width (direction shown by arrows A and B). The fresh toner
chamber
33 has a bottom wall in which a plurality of openings
24
are formed. As shown in FIG. 4, the plurality of openings
24 are aligned
in the direction of length of the cartridge case
26. The boss
30
of the side wall
27 receives an operating knob
36. The operating
knob
36 includes a knob
37 and a shutter
38 formed in one-piece
construction. The shutter
38 is configured to the inner wall of the fresh
toner chamber, thereby closing the opening
24. The knob
36 has a
guide groove
39 formed in its outer surface. The guide groove
39
receives projections
67a and
67b of the print process
cartridge
16, which will be described later. The knob
36 has a groove
40 formed therein as shown in FIG.
5. The groove
40 receives
a seal sponge
41a in the shape of a doughnut. The seal sponge
41a
prevents the fresh, unused toner in the fresh toner chamber
33 from
leaking from the operating knob
36 side. A seal sponge
41b is
mounted by, for example, an adhesive to the outer peripheral portion of the shutter
38. The seal sponge
41b closes the opening
24 when
the shutter
38 is at a predetermined position. The seal sponge
41b
prevents the unused toner in the fresh toner chamber
33 from leaking
through the opening
24. The side plate
29 is generally configured
to the cross section of the body case
28. The side plate
29 has an
opening
42 formed therein. The waste toner recovered from outside the toner
cartridge is introduced into the waste toner chamber
34 through the opening
42. The side plate
29 has two holes
43 and
44 that
receive later described bosses
49 and
54. The holes
43 and
44 correspond to the fresh toner chamber
33 and the waste toner chamber
34. The side plate
29 has projections
45 formed on end surfaces
of the side plate
29. When the side plate
29 is assembled to the
body case
28, the projections
45 fit into the fitting holes
32
formed in the body case
28. The side plate
29 also has a recess
46
formed in its side surface. The recess
46 receives a projection that will
be described later, thereby preventing the toner cartridge
17 from rotating
or disengaging from the print process cartridge. The seal sponge
47 having
substantially the same shape as the side plate
29 is provided in intimate
contact with the side plate
29.
The waste toner chamber
34 includes a spiral shaft
48 that serves
as a toner-advancing member. The spiral shaft
48 has a length that spans
substantially across the length of cartridge case
17. The spiral shaft
48
is received at its one end by a recess
49b formed in a boss
49.
The boss
49 is rotatably received in a bearing hole
43 in the side
plate
29 shown in FIG.
8. The spiral shaft
48 has a projection
48 that abuts a projection
49a formed on the boss
49.
The spiral shaft
48 is supported at its another end by a bearing
50.
The bearing
50 is formed on the side wall
27 in one piece with the
body case
28. The fresh toner chamber
33 incorporates a toner agitating
mechanism
51 and an opening
24, and holds toner. The toner agitating
mechanism
51 agitates the toner. The toner falls by its weight through the
opening
24. The toner is supplied through the opening
24 into the
developing unit. The toner agitating mechanism
51 has a length that spans
substantially across the length of the cartridge
17 as shown in FIG.
7.
The toner agitating mechanism
51 has an agitating shaft
52 that includes
a first crank
52a, and a second crank
52b. The first
crank
52a agitates the toner. The second crank
52b opposes
the first crank
52a. The toner agitating mechanism
51 has
a toner-agitating shaft
52. The toner-agitating shaft
52 extends
across the walls
27 and
29 and is rotatable. The agitating shaft
52 is near the opening
24. A flap
53 is securely fixed at
its upper end to an upper wall of the body case
28. The flap
53 has
a lower end that abuts the first crank
52a when the first crank
52a
reaches near its top dead center. The agitating shaft
52 has one end
received in a bearing
54b in a boss
54. The boss
54
is received in the hole
44. The first crank
52a of the agitating
shaft
52 abuts at its one longitudinal end the projection
54a.
The projection
54a is on the boss
54. The operating knob
36
is fitted into the boss
30. The boss
30 is on the side wall
27
in one piece with the body case
28. As shown in FIG. 9, the operating knob
36 has a recess in the shape of a truncated circular cone and concentric
to the knob
36.
A bearing or retainer
55 is in the shape of a truncated circular cone
and
is fixed to the operating knob
36. The bearing
55 is made of a film
material. The other end of the agitating shaft
52 fits into a groove formed
in a piece
56. The piece
56 has a certain thickness so that the second
crank
52b does not interfere with the bearing
55. The other
end of the agitating shaft
52 is rotatably supported in the middle portion
of the bearing
55. The bosses
49 and
54 are coupled to a gear
train
61 through resilient ratchets.
As shown in FIG. 8, the gear train
61 drives the bosses
49 and
54
in rotation. The gear train
61 is coupled to a drive force transmitting
gear
68 on the print process cartridge
16. When the drive force transmitting
gear
68 rotates, the gear train
61 rotates. When the drive source
69 rotates, the drive force transmitting gear
68 is driven in rotation
by the drive source
69. A drive source
69 is on the electrophotographic
color recording apparatus side. The print process cartridge
16 can be moved
into and out of engagement with the drive source
69.
FIG. 11 is a fragmentary perspective view of a toner cartridge
17.
FIG. 1 is a cross sectional view of the toner cartridge
17 taken along
line I—I of FIG.
11.
The second crank
52b has one end pivotally coupled to a first end
of the fine shaft
57. A second end of the fine shaft
57 fits slidably
into a guide
58. The guide
58 is provided in the top wall of the
body case
28 and has a top wall in the form of a film
60a.
There is provided a magnetic body
59 on the second end of the fine shaft
57. The agitating shaft
52 rotates in a direction shown by an arrow
shown in FIG.
1. As the agitating shaft
52 rotates, the second crank
52b approaches its top dead center and then passes the top dead center.
The permanent magnet
12 is attracted to the magnetic body
59 every
time the second crank
52b approaches its top dead center and then
passes the top dead center. The permanent magnet
12 is attracted to the
magnetic body
59 through the film
60a. The permanent magnet
12 is fixed to one end of the sensor lever
14. The sensor lever
14
performs a rocking motion about a supporting shaft
13 due to attraction
force of the permanent magnet
12. The sensor lever
14 causes the
sensor
15 to be ON and OFF. The film
60a has a thickness of
0.2 mm and is colorless and transparent or colorless and translucent. The film
60a allows visual check of the color of toner held in the cartridge.
The toner cartridge
17 receives inadvertent shock and vibration before it
is completely attached to the print process cartridge
16. The agitating
shaft
52 of the toner cartridge
17 may rotate due to vibration. The
toner cartridge
17 has the following configuration in order to prevent inadvertent
rotation of the agitating shaft
52.
The shutter
38 has an anti-rotation film
60b provided on
the inner side thereof. The boss
54 has a projection
54a.
The first crank
52a is sandwiched between a projection
54a
and the anti-rotation film
60b.
FIG. 12 is a perspective view of the print process cartridge. The print process
cartridge
16 has side walls
63 and
64 formed in one piece.
The side walls
63 and
64 extend upwardly from longitudinal ends of
the side body case
62. As shown in FIG. 3, the body case
62 includes
a photoconductive drum
18, a charging roller
19, a developing roller
20, a cleaning blade
21, and a toner supplying roller
23.
The side wall
63 includes a waste toner exit
65 and a projection
66. The waste toner exit
65 serves as a discharging opening through
which the waste toner is discharged into the toner cartridge
17. When toner
cartridge
17 is attached to the print process cartridge
16, the waste
toner exit
65 fits to the opening
42. When the toner cartridge
17
is attached to the print process cartridge
16, the projection
66
fits into the recess
46. The side wall
64 has projections
67a
and
67b formed thereon. When the toner cartridge
17 is
attached to the print process cartridge
16, the projections
67a
and
67b enter and fit into a guide groove
39 formed in
the operating knob
36 as shown in FIG.
4.
FIG. 13 is a control block diagram illustrating the operation of detecting an
amount of the remaining toner in the toner cartridge. The controller
70
includes a sensor
15, a display
71, a central processing unit
70a
(referred to as CPU
70a) and a memory
70b. The
memory
70b stores a threshold value below which it is determined
that the toner cartridge
17 should be replaced. The memory
70b
stores a message of replacement of the toner cartridge
17 that is displayed
on a display
71.
The operation of attaching the toner cartridge into the print process cartridge
will now be described.
FIG. 14 illustrates the operation of attaching the toner cartridge.
FIG. 15 illustrates the operation of attaching the toner cartridge.
FIG. 16A illustrates the knob
37 before it is rotated.
FIG. 16B illustrates the knob
37 after it is rotated.
The toner cartridge
17 is first inserted into the print process cartridge
as shown in FIG.
14. The toner exit
65 fits into the opening
42
formed in a side frame
29. At this moment, the first crank
52a
of the agitating shaft
52 is at its bottom dead center and the first
crank
52a is sandwiched between the projection
54a of
the boss
54 and the anti-rotation film
60b. Because the agitating
shaft
52 is sandwiched, the agitating shaft
52 will not rotate even
if the toner cartridge is subjected to vibration. When the first crank
52a
is at its bottom dead center, the second crank
52b is at its
top dead center. When the second crank
52b is at its top dead center,
the fine shaft
57 is close to the upper wall. The gap between the film
60a
and the magnetic body
59 mounted on the fine shaft
57 is small.
The film
60a is mounted to the upper wall of the guide
58.
First, the toner cartridge
17 is held horizontal and the operating knob
36 side is lowered. At this stage, the projection
66 fits to the
recess
46 shown in FIG.
5. The recess
46 is formed in the
side frame
29. The projection
66 in on the print process cartridge.
As the operating knob
36 is lowered, the projections
67a and
67b enter the guide groove
39 as shown in FIG.
15.
The projections
67a and
67b are on the print process
cartridge
16. The guide groove
39 is formed in the knob
37.
When the toner cartridge
17 becomes horizontal, the knob
37 is rotated
in a direction shown by arrow C as shown FIG.
16A. When the knob
37
is rotated in a direction shown by arrow C, the projections
67a and
67b fit into the guide groove
39 of the toner cartridge. When
the projections
67a and
67b fit into the guide groove
39 of the toner cartridge, the toner cartridge
17 is fixed to the
print process cartridge
16. The shutter
38 has the knob
37
in one piece. When the shutter
38 is rotated in the direction shown by arrow
C, the toner is supplied through the opening
24. The fresh, unused toner
is supplied through the opening
24 from the fresh toner chamber to the print
process cartridge
16.
The operation of detecting an amount of the remaining toner in the toner cartridge
will now be described.
FIGS. 17A-17C illustrate the remaining toner in the toner cartridge.
FIG. 17A illustrates when the remaining toner is sufficient.
FIG. 17B illustrates when the remaining toner is not sufficient.
FIG. 17C illustrates when the toner cartridge is empty of toner.
FIGS. 18A-18E are illustrative diagrams that illustrate the operation of detecting
remaining toner.
FIG. 18A is an illustrative diagram (A), illustrating the operation of the agitating
shaft and the sensor.
FIG. 18B is an illustrative diagram (B), illustrating the operation of the agitating
shaft and the sensor.
FIG. 18C is an illustrative diagram (C), illustrating the operation of the agitating
shaft and the sensor.
FIG. 18D illustrates the ON/OFF conditions at a toner LOW condition in which
remaining toner is not sufficient.
FIG. 18E illustrates the ON/OFF conditions at a toner FULL condition in which
remaining toner is sufficient.
The image forming section
5 causes the spiral shaft
48 and agitating
shaft
52 to rotate while printing is being performed. The image forming
section
5 causes the cleaning blade
21 shown in FIG. 3 to scratch
the residual toner that has failed to be transferred onto the print medium during
printing. As shown in FIG. 15, the image forming section
5 causes the scratched
residual toner to fall into the waste toner chamber
34 through the waste
toner exit
65 of the print process cartridge
16. When the waste toner
piles up as high as the spiral shaft
48, the spiral shaft
48 makes
the top of the pile of the waste toner horizontal. The spiral shaft
48 moves
the waste toner further into the waste toner chamber
34 away from the opening
42. Continuing the above operation, the spiral shaft
48 causes the
waste toner to pile up in the waste toner chamber
34. The agitating shaft
52 in the fresh toner chamber
33 rotates to prevent the toner from
clumping. Meanwhile, the CPU
70a in the controller
70 detects
an amount of the remaining toner in the toner cartridge
17 by means of the
sensor
15. When the remaining toner in the toner cartridge
17 is
sufficient as shown in FIG. 17A, the CPU
70a operates as follows:
That is, the second crank
52b of the agitating shaft
52 reaches
a position shown in FIG.
18A. When the second crank
52b reaches
the point shown in FIG. 18A, the magnetic body
59 attracts the permanent
magnet
12. The magnetic body
59 is provided on the other end of the
fine shaft
57. The permanent magnet
12 is fixed to one end of the
sensor lever
14. When the permanent magnet
12 is attracted to the
magnetic body
59, the sensor lever
14 causes the sensor to become
ON as shown in FIG.
18E. At this moment, the projection
54a shown
in FIG. 8 abuts the first crank
52a and rotates as the boss
54
rotates. When the boss
54 causes the first crank
52a to rotate,
the first crank
52a pushes the anti-rotation film
60b to
flex so that the first crank overrides the anti-rotation film
60 and continues
to rotate.
The projection
54a is formed on the boss
54 that rotates
together with the gear train
61. The second crank
52b reaches
a position shown in FIG.
18B. One end of the sensor lever
14 leaves
the second end of the fine shaft
57, making the sensor
15 OFF as
shown in FIG.
18E. The CPU
70a causes a built-in timer to
count the time t during which the sensor
15 is ON. The CPU
70a
monitors the timer to determine whether the time t exceeds a threshold value.
The threshold value is stored previously in a memory
70b. In the
embodiment, the threshold value is set to, for example, T/2 where T is the time
required for the agitating shaft
52 to make one complete rotation. As shown
in FIG. 17A, when the remaining toner in the toner cartridge
17 is sufficient,
the ON time of the sensor
15 does not exceed the threshold value. If the
remaining toner in the toner cartridge
17 is little as shown in FIG. 17B,
the second crank
52b abuts the tip portion of the flap
53
when the crank
52b reaches the position shown in FIG.
18A.
When the second crank
52b reaches the position shown in FIG. 18C
as the boss
54 rotates, the second crank
52b is at the position
just before the second crank
52b leaves the flap
53. When
the first crank
52a further rotates as the boss
54 rotates,
the first crank
52a leaves the tip of the flap
53. Due to
its own weight, as shown in FIG. 17B, the first crank
52a rotates
toward the bottom dead center. At this moment, the second crank
52b moves
toward the top dead center and causes the sensor
15 to become ON as shown
in FIG.
18D. The first crank
52a waits at the bottom dead
center until the boss
54 reaches the first crank
52a. When
the boss
54 has reached the first crank
52a, the first crank
52a starts rotating again together with the boss
54. When
the second crank
52b reaches the position shown in FIG. 18B, a part
of the sensor lever
14 leaves the fine shaft
57. When one end of
the sensor lever
14 leaves the second end of the fine shaft
57, the
sensor
15 becomes OFF as shown in FIG.
18C. The CPU
70a
causes the built-in timer to count the ON time of the sensor
15 for
which the sensor
15 remains ON. The CPU
70a compares the ON
time of the sensor
15 with the threshold value to check whether the ON time
exceeds the threshold value.
The threshold value is stored in the memory
70b. In the present
embodiment, the threshold value is set to, for example, T/2 where T is the time
required for the agitating shaft
52 to make one complete rotation. If the
ON time t of the sensor
15 exceeds the threshold value as shown in FIG.
18D, the CPU
70a reads a message that prompts replacement of the
toner cartridge. Subsequently, the CPU
70a displays the message on
the display
71. When the toner exerts a load on the fine shaft
57,
the fine shaft
57 flexes while rotating. The fine shaft
57 resiliently
flexes to absorb the force exerted by the toner. The fine shaft
57 flexes
to prevent further increase in the load exerted on the agitating shaft
52.
When the load on the agitating shaft is prevented from increasing, the drive force
of the drive gear
68 is enough to drive the agitating shaft in rotation.
Because the load is reduced, the agitating shaft
52 can agitate the toner.
Since the toner is agitated, printing can be performed normally. Due to the fact
that the fine shaft
57 flexes, the magnetic body
59 may not reach
a position where the magnetic body
59 operates normally. When the magnetic
body
59 does not reach the position where the magnetic body operates normally,
an attraction force does not act between the magnetic body
59 and the permanent
magnet
12. In this case, the sensor lever
14 does not move together
with the permanent magnet
12. Because the sensor lever
14 does not
move, the sensor
15 cannot detect the ON state. Thus, the remaining toner
cannot be detected from the output signal of the sensor
15. However, the
fine shaft
57 can move due to the toner-agitating operation. When the fine
shaft
57 moves, the rod
57 interferes with lumps of toner and crushes
the lumps. The fine shaft
57 bumps the lumps of toner a plurality of times
to crush the lumps of toner. When the lumps of toner become extinct, the normal
attraction force acts between the magnetic body
59 and the permanent magnet
12 so that the magnet
12 causes the sensor lever
14 to operate
normally. When the sensor lever
14 operates, the sensor
15 detects
the ON state, thereby allowing detecting of the remaining toner from the output
signal of the sensor
15. The fine shaft
57 is made of a stainless
steel (SUS304-WPB, longitudinal modulus of elasticity E=1.9×10
3 kgf/mm
2,
lateral modulus of elasticity G=7×10
3 kgf/mm
2) having
a diameter of 0.6 mm. The fine shaft
57 has a helical end that is curled
around the second crank
52b of the agitating shaft
52. The
fine shaft
57 is made of a stainless steel having a diameter of 0.6 mm for
the following reasons.
The early density of sufficiently agitated toner in the toner cartridge is as
follows: Y=0.345-0.385 (g/cm
3), M=0.345-0.385 (g/cm
3), C=0.335-0.375
(g/cm
3), B=0.350-0.390 (g/cm
3). Vibration is given to the
toner to increase its apparent density by a factor of two. Then, by using the toner
having an apparent density of toner substantially twice the normal toner density,
an experiment was conducted to evaluate the ability of the fine shaft
57
to detect an amount of the remaining toner. The experiment was conducted for different
diameters of the fine shaft
57 in the range of 0.2 to 1.0 mm, in increments
of 0.1 mm. The results are as follows:
Diameters greater than 0.8 mm increases the rigidity of the fine shaft
57 and makes the rod
57 difficult to flex. Diameters greater than
0.8 mm provides the same results as the conventional art. Diameters greater than
0.8 mm exerts a large load on the bearing on which the agitating shaft rotates
and the drive gear
68. Too large a load on the drive gear
68 prevents
the toner from being agitated, so that the image forming section
5 cannot
perform printing normally. Additionally, the image forming section fails to detect
the remaining toner in the toner cartridge.
When the diameter of the fine shaft
57 is less than 0.4 mm, once the
fine shaft
57 flexes, it cannot regain its original shape. When the diameter
is less than 0.4 mm, even if the non-clumped density of toner is as good as initial
value, the remaining toner sensor cannot be operated to become ON and OFF. When
the diameter is less than 0.4 mm, detection of remaining toner of the fine shaft
57 malfunctions. If the deformed fine shaft
57 is operated, the fine
shaft
57 may interfere with the surroundings. The image forming section
5 cannot perform the normal printing operation because the fine shaft
57
is exerted an increased load. Thus, the diameter of the fine shaft
57 is
in the range of 0.4 to 0.8 mm and preferably 0.6 mm. The fine shaft
57 may
not be made of stainless steel in its entirety but may be in part. In the first
embodiment, a part of the fine shaft
57 is made of a material such that
when the part receives pressures greater than a predetermined value, then the part
absorbs the pressure. In particular, the fine shaft
57 should be made of
flexible stainless steel having a diameter of 0.6 mm. The toner may clump in the
toner cartridge due to vibration added from outside. However, the fine shaft
57
has a small diameter that allows the fine shaft
57 to flex to absorb the
load of the toner. Therefore, the fine shaft
57 can operate normally even
if the toner is clumped. The toner cartridge has an anti-rotation film
60b
so that the first crank is sandwiched between the anti-rotation film
60b
and the projection of the boss. The first crank is held between the projection
and the anti-rotation film
60b. The anti-rotation film
60b
has resiliency and is a thin plate of, for example, polyethylene terephthalate
(PET) having a thickness of 0.1 mm. The anti-rotation film
60b extends
along the first crank
52a. The anti-rotation film
60b has
a height such that the anti-rotation film
60 extends at least across the
rotational path of the first crank
52a. The forces exerted on the
anti-rotation film
60 by the free motion of the agitating shaft
52
during transportation are much smaller than the force exerted on the anti-rotation
film
60 by the drive source
69 during printing. Thus, the anti-rotation
film
60
