Image forming apparatus and toner supply method

Image forming apparatus and toner supply method
US008483583B2
(12) Ulllted States Patent
(10) Patent N0.:
Takehara et al.
(54)
US 8,483,583 B2
(45) Date of Patent:
IMAGE FORMING APPARATUS AND TONER
(56)
Jul. 9, 2013
References Cited
SUPPLY METHOD
U.S. PATENT DOCUMENTS
(75)
Inventors: Atsushi Takehara, Kyoto (JP); Naoki
2006/0198644 A1 *
9/2006 Itagaki et a1. ................. .. 399/27
Nakatake’ Hyogo (1p); Tetsumaru
2008/0075480 A1
3/2008 Konishi et a1.
Fujita’ Hyogo (JP); Tomohiro Kubota’
Osaka (JP); Kohta Sakaya, Osaka (JP)
2010/0098441 A1
4/2010 Mlyazaki et a1.
FOREIGN PATENT DOCUMENTS
(73) Assignee: Ricoh Company, Ltd., Tokyo (JP)
JP
4026977
10/2007
JP
2009-75244
4/2009
OTHER PUBLICATIONS
( * ) Notice:
subjeqto any disclaimeri the term Ofthis
Of?ce Action issued Aug. 13, 2012, in Chinese Patent Application
patent 1s extended or adjusted under 35
N0. 2011101054804 with English translation.
U.S.C. 154(b) by 245 days.
US. Appl. No. 13/020,405, ?led Feb. 3, 2011, Nakatake, et a1.
(21) Appl. N0.: 13/025,266
* Cited by examiner
Primary Examiner * Walter L Lindsay, Jr.
( 22 )
Filed;
Feb, 11 , 2011
Assistant Examiner * Rodney Bonnette
(74) Attorney,
(65)
Prior Publication Data
US 2011/0217055 A1
Agent,
or
Firm * Oblon,
Spivak,
McClelland, Maier & Neustadt, L.L.P.
(57)
Sep. 8, 2011
_
ABSTRACT_
_
_
Toner 1s suppl1ed from a toner conta1ner to a develop1ng part
that causes the toner to adhere to a latent image formed on a
(30)
Foreign Application Priority Data
Mar. 5, 2010
(51)
(52)
Int. Cl.
G03G 15/08
us CL
latent image carrying member and develops the latent image,
(JP) ............................... .. 2010-049004
a
re-toner-su
l
o eration of su
l in
a
redetermined
anlioum of tong? a ?fe developing 153121: isgcagied out’ a fog
detecting image is formed and fog is detected in the fog
detecting image, a toner supply amount to be supplied to the
(2006.01)
developing part is determined based on the fog detected in the
detecting and an operational status of the developing part
USPC ............................................. .. 399/29, 399/27
(58) Field of Classi?cation Search
Sihee the toner Was supplied to the developing Part the last
time, and the‘ toner supply amount of the toner determined in
USPC .............................................. .. 399/27, 29, 60
‘he de‘ermmmg 1S SuPPhed ‘0 ‘he developmg Pm
See application ?le for complete search history.
10 Claims, 9 Drawing Sheets
To
REMAINING AMOUNT SHO RTAGE
D ETECTED?
YES
MEASURE FOG AMOUNT
(FROM OUTPUT VALUE OF OPTIC-AL SENSOR)
OBTAIN OPERATIONAL STATUS
OF DEVELOPING APPARATUS
PRE~TONER—SUPPLY OPERATION
STIR DEVELOPING APPARATUS (30 SECONDS)
MEASURE FOG AMOUNT
(FROM OUTPUT VALUE OF OPTICAL SENSOR)
OBTAIN OLD TONER AMOUNT
IN DEVELOPING APPARATUS
DETERMINE TONER SUPPLY AMOUNT Xg
STIR DEVELOPING APPARATUS (30 SECONDS)
S11
TONER
REMAINING AMOUNT SHORTAGE
DETECTED?
YES
TONER END INDICATION
US. Patent
Jul. 9, 2013
Sheet 2 of9
US 8,483,583 B2
[email protected]/
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US. Patent
Jul. 9, 2013
Sheet 3 of9
US 8,483,583 B2
F IGZB
Q
925
95)
1 20
MEMORY
CONTROL
PART
POWER
SOURCE
12o
IMAGE FORMING PART
FIG.3
US. Patent
Jul. 9, 2013
Sheet 4 of9
FIG.4
FIG.5
\\
81K
US 8,483,583 B2
US. Patent
Jul. 9, 2013
Sheet 5 of9
US 8,483,583 B2
FIG.6A
@FD/QV
' SKJO I’;
JD- 53
5Y [i1] 21
23
FIG.6B
5K23 ‘32W
52( 51 56
5M
5Y
US. Patent
Jul. 9, 2013
Sheet 6 of9
FIG.7
151
153
152
US 8,483,583 B2
US. Patent
Jul. 9, 2013
US 8,483,583 B2
Sheet 7 0f 9
FIG.8
TONER
REMAINING AMOUNT SHO RTAGE
DETECTED’?
NO
MEASURE FOG AMOUNT
(FROM OUTPUT VALUE OF OPTICAL SENSOR)
I
OBTAIN OPERATIONAL STATUS
OF DEVELOPING APPARATUS
N83
I
PRE-TONER-SUPPLY OPERATION
I
STIR DEVELOPING APPARATUS (30 SECONDS) N85
I
MEASURE FOG AMOUNT
(FROM OUTPUT VALUE OF OPTICAL SENSOR) "\186
I
OBTAIN OLD TONER AMOUNT
IN DEVELOPING APPARATUS
I
DETERMINE TONER SUPPLY AMOUNT Xg
I
SUPPLY TONER
I
STIR DEVELOPING APPARATUS (30 SECONDS)
S11
TONER
REMAINING AMOUNT SHO RTAGE
DETECTED?
TONER END INDICATION
@
NO
N812
US. Patent
Jul. 9, 2013
Sheet 8 of9
US 8,483,583 B2
ow
woze?nw:ma
3E _
US. Patent
02 E
Jul. 9, 2013
Sheet 9 of9
US 8,483,583 B2
US 8,483,583 B2
1
2
IMAGE FORMING APPARATUS AND TONER
SUPPLY METHOD
developing apparatus has thus become approximately empty
BACKGROUND OF THE INVENTION
becomes the neW toner after the neW toner is thus supplied,
of toner, neW toner is supplied from a toner container. There
fore, almost all of the toner in the developing apparatus
and thus, it is possible to prevent fog after the neW toner is
supplied.
1. Field of the Invention
The present invention relates to an image forming appara
HoWever, according to the above-mentioned patent docu
ment 2, the old toner remaining in the developing apparatus is
ejected to the photosensitive member, and thus, is discarded.
tus and a toner supply method.
2. Description of the Related Art
In the related art, a single-component developing apparatus
is knoWn. In the single-component developing apparatus,
As a result, the toner may be Wasted.
A reason Why fog occurs When deteriorated old toner and
developing is carried out in such a manner that a developing
neW toner are mixed Will noW be described concretely.
roller, Which is a toner carrying member, carries toner that is
Old toner remaining in a developing apparatus has suffered
developer of a non-magnetic or magnetic single component,
stress for a long period of time due to such as stirring. As a
result, an external additive that is added externally to surfaces
and the toner on the developing roller is supplied to a latent
image on a photosensitive member, in a developing area in
Which the photosensitive member that is a latent image car
of toner particles for controlling ?oWability and an electri?
cation property may have been removed or may have been
rying member and the developing roller face one another.
In the single-component developing apparatus, the devel
oping apparatus is replaced When the toner in the developing
embedded in the particles. Thereby, the toner may not be
easily electri?ed frictionally to, for example, negative polar
20
apparatus has run out. Therefore, the developing roller for
Which a replacement time has not been reached yet and thus
usage of Which can be continued is also replaced. Thus, a
resource may be Wasted. In a case Where the developing
apparatus is con?gured such that a time at Which the toner in
the developing apparatus runs out and the replacement time of
25
together, charge separation occurs, and electrons in the old
the developing roller and so forth are the same as one another,
it may be necessary to ensure a space for holding a great
amount of toner in the developing apparatus, and thus, the
developing apparatus may be increased in siZe.
toner move to the neW toner. As a result, an electri?cation
30
Japanese Patent No. 4026977 (patent document 1)
describes an image forming apparatus in Which a toner con
tainer that holds toner is provided separate from a developing
apparatus, and a supplying part supplies the toner of the toner
container to the developing apparatus. Thereby, in a case
Where the toner in the toner container has run out, only the
toner container is to be replaced, and thus, a developing roller
for Which usage can be continued is not to be replaced. Fur
ther, because an amount of neW toner to be held by the toner
container may be determined Without regard to a replacement
?cation distribution in the developing apparatus becomes
35
supplied, the deteriorated toner may become Weak electri?ed
toner, or reverse electri?ed toner. Therefore, in an image
forming process after the neW toner is supplied, the above
40
mentioned deteriorated old toner may adhere to an area (other
45
than a latent image area) on a photosensitive member that is
an image carrying member for Which area no toner is desired
to be placed. As a result, fog increases in comparison to a case
before the neW toner is supplied.
Such fog can be reduced by reducing a ratio of deteriorated
siZe.
old toner existing after neW toner is supplied. Therefore, by
patent document 1 , the toner of the toner container is supplied
to the developing apparatus When the toner amount in the
mixed together.
Japanese Laid-Open Patent Application No. 2009-75244
(patent document 2) describes the folloWing image forming
negative polarity is large and an area in Which the electri?ca
tion amount is close to Zero, exist. Thus, after the neW toner is
prevent the image forming apparatus from being increased in
developing apparatus becomes less than a loWer limit value.
Therefore, after the toner is thus supplied to the developing
apparatus, the toner neWly supplied from the toner container
and old toner having remained in the developing apparatus for
a long period of time Without being used for developing are
amount of the neW toner having the negative polarity may
increase, an electri?cation amount of the old toner having the
negative polarity may decrease, or the old toner may be elec
tri?ed to have positive polarity. As a result, the toner electri
broad, and also, such a distribution may occur in Which tWo
peaks, i.e., an area in Which the electri?cation amount to the
time of the developing roller, it is possible to reduce a capacity
of the toner container to be small, and thus, it is possible to
Further, according to the image forming apparatus of the
ity that is normal electri?cation polarity of the toner. On the
other hand, neW toner supplied to the developing apparatus is
not deteriorated and thus, is easily electri?ed frictionally to
the negative polarity. Therefore, When the neW toner that is
easily electri?ed to the negative polarity and the old toner that
is not easily electri?ed to the negative polarity are rubbed
increasing a neW toner amount to be supplied, it is possible to
reduce the ratio of deteriorated old toner in the developing
apparatus Without carrying out the above-mentioned process
50
of ejecting the toner remaining in the developing apparatus,
and thus, it is possible to reduce fog occurring after neW toner
is supplied Without uselessly consuming the toner.
HoWever, When the neW toner amount to be supplied is
increased, the toner amount in the developing apparatus
55
increases, Which may result in an increase in torque of a
apparatus for preventing fog caused as a result of neW toner
stirring member, toner packing or such. Therefore, it is nec
being supplied to a developing apparatus in Which old dete
essary to reduce, as much as possible, the toner amount in the
riorated toner remains. The term “fog” means a phenomenon
that an image area that is to be a blank has a density increased
as a result of toner adhering thereto through a developing
developing apparatus after neW toner is supplied. If the
remaining old toner amount in the developing apparatus can
be precisely determined When neW toner is supplied, it is
60
process. That is, When a toner amount in the developing
apparatus becomes less than a loWer limit value, such control
is carried out that, before toner is supplied to the developing
apparatus, the toner remaining in the developing apparatus is
ejected toWard a photosensitive member. Thereby, the old
toner remaining in the developing apparatus is ejected to the
photosensitive member, and, in a condition in Which the
possible to supply a minimum necessary amount of neW toner
to the developing apparatus such that fog occurring after the
neW toner is supplied can be made to be an alloWable level,
65
and it is possible to prevent the toner amount in the develop
ing apparatus after the neW toner is supplied from becoming
larger than the necessary amount. The term “toner packing”
means a phenomenon that toner solidi?es, or a phenomenon
US 8,483,583 B2
3
4
that ?uidity of toner remarkably degrades. Toner packing may
supplied to the developing part the last time, Wherein the toner
supplying part supplies the neW toner supply amount of the
occur as a result of toner being pressed at high pressure, and
may result in an increase of a torque of a machine that pro
neW toner determined by the toner supply amount determin
cesses the toner or a structure that passes the toner there
ing part to the developing part.
through is clogged by the toner.
According to another embodiment of the present invention,
A remaining amount detecting part that detects a toner
a toner supply method of supplying toner from a toner con
tainer to a developing part that causes the toner to adhere to a
remaining amount in the developing apparatus in the related
art is such that a pieZoelectric sensor is provided in the devel
latent image formed on a latent image carrying member and
develops the latent image, includes carrying out a pre-toner
oping apparatus and a remaining amount in the developing
apparatus is detected by using an output of the pieZoelectric
provided to the developing apparatus, a transmission optical
supply operation of supplying a predetermined amount of
toner to the developing part; forming a fog detecting image
and detecting fog in the fog detecting image; determining a
sensor is used to detect Whether toner exists in the detecting
WindoW to detect a height of the toner in the developing
apparatus, and a remaining amount is detected from the
toner supply amount to be supplied to the developing part
based on the fog detected in the detecting and an operational
status of the developing part since the toner Was supplied to
detected height of the toner in the developing apparatus.
HoWever, in the remaining amount detecting method of using
the pieZoelectric sensor, precise remaining amount detection
the developing part the last time; and supplying the toner
sensor. Another example is such that a detecting WindoW is
supply amount of the toner determined in the determining to
the developing part.
may not be carried out When a deviation occurs in a toner
amount betWeen a place at Which the pieZoelectric sensor is
provided and a place at Which the pieZoelectric sensor is not
BRIEF DESCRIPTION OF THE DRAWINGS
20
provided. Further, in the remaining amount detecting method
of using the transmission optical sensor, precise remaining
FIG. 1 is a graph shoWing a result of investigating a rela
tionship betWeen a ratio of neW toner With respect to all the
amount detection may not be carried out When a deviation
toner amount in a developing part and summing;
occurs in a toner amount betWeen a place at Which the trans 25
FIG. 2A shoWs a general partial con?guration of a printer
mission optical sensor is provided and a place at Which the
transmission optical sensor is not provided. Thus, it may be
dif?cult to precisely determine a toner remaining amount in
according to an embodiment of the present invention;
FIG. 2B shoWs a block diagram shoWing a relationship
betWeen a control part and a poWer source included in the
printer and the image forming part shoWn in FIG. 2A;
the developing apparatus in the related art, and thus, it may
not be possible to supply, based on a detection result of the
30
FIG. 3 shoWs a general con?guration of a process cartridge
for a color K (black) and parts around it in the printer shoWn
remaining amount detecting part, a minimum necessary
amount of neW toner to the developing apparatus such that fog
in FIG. 2;
occurring after the neW toner is supplied can be made to be an
alloWable level. Therefore, neW toner may be supplied in an
FIG. 4 illustrates a positional relationship betWeen a Waste
toner collecting belt and other members of the process car
amount larger than the necessary amount, and thus, it may not
be possible to suf?ciently prevent an increase in torque of a
rotating member such as a stirring member, toner packing, or
35
such in the developing apparatus.
tridge for the color K shoWn in FIG. 3;
FIG. 5 shoWs a plan vieW of a developing apparatus for the
color K shoWn in FIGS. 2 and 3;
FIGS. 6A and 6B shoW a general con?guration of a contact/
apart mechanism in the printer of the embodiment of the
SUMMARY OF THE INVENTION
40
FIG. 7 shoWs a general con?guration of a re?ection optical
sensor in the printer of the embodiment of the present inven
According to one embodiment of the present invention, an
image forming apparatus includes a latent image carrying
member that carries a latent image; an electrifying part that
electri?es a surface of the latent image carrying member; a
present invention;
tion;
FIG. 8 shoWs a ?owchart of a toner supply control opera
ber to a surface of an endless moving member in Which the
tion according to the embodiment of the present invention;
FIG. 9 shoWs fog variation according to aging of an image
forming apparatus in Which the toner supply control opera
tion according to the embodiment of the present invention is
carried out and fog variation according to aging of an image
forming apparatus in the related art;
FIG. 10 shoWs a general partial con?guration of a direct
surface is moved in an endless manner or a recording member
transfer-type image forming apparatus.
45
latent image Writing part that Writes the latent image on the
latent image carrying member; a developing part that devel
ops the latent image on the latent image carrying member by
using toner and obtains a toner image; a transferring part that
transfers the toner image on the latent image carrying mem
50
held on the surface of the endless moving member; a toner
container that holds neW toner to be supplied to the develop
ing part; a toner supplying part that supplies the neW toner
held by the toner container to the developing part; a fog
detecting part that detects fog of an image; and a toner supply
55
DETAILED DESCRIPTION OF THE
EMBODIMENTS
60
An embodiment of the present invention has been devised
in consideration of the above-mentioned problems, and an
object of the embodiment of the present invention is to pro
vide an image forming apparatus and a toner supply method
amount determining part that, prior to supplying the neW
toner to the developing part, carries out a pre-toner-supply
operation of supplying a predetermined amount of the neW
toner to the developing part, forms a fog detecting image after
in Which it is possible to prevent useless toner consumption,
prevent fog occurring after neW toner is supplied, and also,
the pre-toner supply operation, detects fog in the fog detect
ing image by means of the fog detecting part, and determines
a neW toner supply amount to be supplied to the developing
part based on a detection result obtained from the fog detect
ing part detecting fog in the fog detecting image and an
operational status of the developing part since neW toner Was
prevent an increase in torque and toner packing in a develop
ing apparatus or developing part.
65
A relationship betWeen a ratio of neW toner With respect to
all the toner amount in a developing part and fog Was inves
tigated, and it Was found out that the relationship shoWn in
US 8,483,583 B2
5
6
FIG. 1 existed. The relationship between a ratio of neW toner
becomes such an amount that fog can be made to be an
With respect to all the toner amount in the developing part and
fog Was investigated in a method described below. First, a
developing part of a printer Ipsio C220 Was ?lled With toner,
alloWable level. For example, as shoWn in FIG. 1, When the
running distance of the developing roller as an operational
status is 10 km, it is possible to make fog to be an alloWable
and a durability test Was carried out such that a running
level by making the ratio of neW toner to be equal to or more
than approximately 70%. Therefore, neW toner is to be sup
plied by an amount such that a ratio of neW toner becomes
distance of a developing roller (outer perimeter><number of
revolutions of the developing roller) at room temperature Was
5 km and 10 km. After the durability tests, the toners Were
extracted from the developing part. The extracted toners Were
used as old toners remaining in the developing part and neW
equal to 70%. Further, When the running distance of the
developing roller as an operational status is 5 km, it is possible
to make fog to be an alloWable level by making the ratio of
toner Was used as neW toner to be supplied to the developing
neW toner to be equal to or more than 58%. Therefore, neW
part, and mixed toners having mutually different mixing
toner is to be supplied by an amount such that a ratio of neW
ratios of the old toner and the neW toner Were prepared. Then,
toner becomes equal to 58%. Thus, it is possible to supply
by using the mixed toners having mutually different mixing
neW toner by a minimum necessary amount such that fog can
ratios, blank paper images as fog detecting images Were
be made to be an alloWable level. Thus, it is possible to
prevent a toner amount in the developing part from becoming
excessive. As a result, it is possible to prevent an increase in
formed on a photo sensitive member as a latent image carrying
member, and toner amount levels (fog amounts) on the pho
tosensitive member Were measured. Thus, the relationship
torque and toner packing in the developing part. Further,
because it is possible to make fog to be an alloWable level
betWeen a ratio of neW toner With respect to all the toner
20
Without carrying out the above-mentioned process of ej ecting
the toner remaining in the developing part, it is possible to
avoid useless toner consumption, and prevent fog after neW
toner is supplied.
Thus, according to the embodiment of the present inven
25
is noted that in FIG. 1, for the sake of convenience, the upper
direction denotes a direction in Which the fog amount
tion, it is possible to avoid a Waste of toner, avoid fog occur
ring after neW toner is supplied, and also, avoid an increase in
torque of a rotating member such as a stirring member and
decreases, i.e., the fog situation becomes better, and the loWer
toner packing.
amount in the developing part and fog Was investigated. FIG.
1 shoWs the results. A broken line in FIG. 1 shoWs a relation
ship betWeen a ratio of neW toner With respect to all the toner
amount in the developing part and fog in the case Where the
toner extracted after the durability test of the running distance
of the developing roller of 10 km Was used as the old toner. It
direction denotes a direction in Which the fog amount
increases, i.e., the fog situation becomes Worse. A solid line in
BeloW, an embodiment of an electrophotographic printer
30
(simply referred to as a printer, hereinafter) as an image
FIG. 1 shoWs a relationship betWeen a ratio of neW toner With
forming apparatus according to the present invention Will
respect to all the toner amount in the developing part and fog
noW be described.
in the case Where the toner extracted after the durability test of
the running distance of the developing roller of 5 km Was used
First, a basic con?guration of a printer 100 Will noW be
as the old toner. As can be seen from FIG. 1, it is possible to 35
determine a neW toner amount With respect to all the toner
amount in the developing part and an old toner amount With
respect to all the toner amount in the developing part When an
operational status of the developing part (i.e., a running dis
tance of the developing roller in this example) and fog are
determined.
Therefore, according to an embodiment of the present
invention, an old toner amount remaining in a developing part
is precisely determined by the folloWing method. First, a
pre-toner-supply operation is carried out, and thus, a prede
respectively, hereinafter) toner images, respectively. These
40
four process cartridges 10Y, 10M, 10C and 10K useY, M, C
and K toners of mutually different colors, respectively. Other
than this point, these four process cartridges 10Y, 10M, 10C
and 10K have the same con?gurations as each other, and are
replaced When they come to the ends of their lives, respec
45
tively. FIG. 2B shoWs a control part 90 and a poWer source
110 included in the printer 100. The control part 90 controls
termined amount of neW toner is supplied to the developing
part. Thereby, neW toner having a certain ratio With respect to
operations of various parts/ components included in the image
all the toner in the developing part exists. By using the devel
oping part having this condition, a fog detecting image is
formed, and fog is detected in the fog detecting image. Then,
described. FIG. 2A shoWs a general partial con?guration of
an image forming part 120 of the printer 100. In FIG. 2A, the
image forming part 120 of the printer 100 includes four pro
cess cartridges 10Y, 10M, 10C and 10K for forming yelloW,
magenta, cyan and black (simply referred to asY, M, C and K,
forming part 120 of the printer 100. The poWer source 110
supplies poWer to the various parts/components included in
50
the image forming part 120 of the printer 100. To take the
from a detection result of the fog being detected in the fog
process cartridge 10K for forming a K toner image as an
detecting image and the operational status of the developing
part (the running distance of the developing roller), it is pos
example, as shoWn in FIG. 3, the process cartridge 10A
sible to determine the certain ratio of the neW toner With
image carrying member, an electrifying apparatus 2K, a
developing apparatus 4K and a drum cleaning apparatus 6K
respect to all the toner in the developing apparatus after the
pre-toner-supply operation, as shoWn in FIG. 1. Because the
neW toner amount supplied to the developing part at the time
includes a drum-like photosensitive member 1K as a latent
55
as a toner removing part. The process cartridge 10K is detach
able from the body of the printer 100, and has such a con?gu
of the pre-toner-supply operation is knoWn, it is possible to
precisely determine the old toner amount remaining in the
developing part from the certain ratio of the neW toner in the
developing part obtained based on the fog detection result and
the operational status, and the neW toner amount supplied to
the developing part at the time of pre-toner-supply operation.
Thus, it is possible to precisely determine the old toner
amount in the developing part, and thus, it is possible to
determine a neW toner amount to be supplied to the develop
ing part so that a ratio of neW toner in the developing part
ration that consumable parts can be replaced at a time.
The electrifying apparatus 2K as an electrifying part is
60
65
con?gured so that a high voltage of a metal core of an elec
tri?cation roller (2K), Which is in contact With a surface of the
photosensitive member 1K and thus is rotated along With
rotation of the photosensitive member 1K, is applied to the
surface of the photosensitive member 1K, and the surface of
the photosensitive member 1K is thus uniformly electri?ed.
Instead of the electri?cation roller (2K) that is the electrifying
part in a contact type, a corotron-type or a scorotron type
US 8,483,583 B2
7
8
electri?cation unit that discharges electricity as a result of a
of the developing apparatus 4K is promoted as the toner is
stirred by the agitator 43K and the toner is electri?ed in the
high voltage being applied to a charging Wire, and further, an
normal electri?cation polarity (negative polarity). Therefore,
electri?cation brush, an electri?cation sheet, a stylus elec
trode, or such, may be used. These are advantageous in that
the toner held by the toner supply roller 42K and conveyed to
the part at Which the toner supply roller 42K is in contact With
the developing roller 41K moves from the toner supply roller
42K to the developing roller 41K by the in?uence of the
electric ?eld, and statically adheres to the developing roller
41K. A layer thickness of the K toner adhering to the devel
oping roller 41K on the surface of the developing roller 41K
is controlled by the lamellation blade 45K When the K toner
on the developing roller 41K passes a position along With
rotation of the developing roller 41K at Which the developing
they can electrify the surface of the photosensitive member
1K in a non-contact manner, and thus, are not easily affected
by a cleaning property. However, an amount of discharge
product such as oZone, NOx or such, generated along With
discharging, is remarkably larger than that in the case of using
the electri?cation roller, and therefore, a problem may arise
concerning durability of the photosensitive member 1K.
The developing apparatus 4K is a single-component devel
oping apparatus, and includes a developing roller 41K as a
toner carrying member, and a toner supply roller 42K as a
roller 41K is in contact With the lamellation blade 45K. The K
toner supply member that supplies toner to the developing
toner, after the layer thickness thereof is thus controlled,
roller 41K. Above the developing apparatus 4K, a toner con
tainer 7K is provided. In the toner container 7K are included
a toner storage part 71K that stores neW toner and a Waste
toner receiving part 72K that is provided above the toner
storage part 71K and receives Waste toner. In the toner storage
part 71K are provided an agitator 71aK that is driven and
rotated by a driving part not shoWn, and a conveying member
20
adheres to an electrostatic latent image for the color K formed
on the photosensitive member 1K for the color K at a devel
oping area that is a part at Which the developing roller 41K is
in contact With the photosensitive member 1K. As a result of
the adhesion, the electrostatic latent image for the color K is
developed by the K toner into a K toner image.
71bK that includes a screW or a coil and conveys the neW toner
FIG. 4 illustrates a positional relationship betWeen a Waste
from the inside of the toner storage part 71K toWard a toner
toner collecting belt 63K provided in the process cartridge
supply port not shoWn acting as a connection part connecting
betWeen the developing apparatus 4K and the toner storage
part 71K. The conveying member 71bK is driven and rotated
by a driving part not shoWn. It is preferable that the agitator
25
71aK is at any time driven and rotated to stir the neW toner in
the inside of the toner storage part 71K for the purpose of
maintaining ?oWability of the neW toner in the inside of the
30
toner storage part 71K.
In the developing apparatus 4K are provided a toner trans
porting member 44K that includes a screW or such for con
veying the neW toner of the toner storage part 71K supplied
10K and not shoWn in FIG. 3 and other members of the
process cartridge 10K.
35
At an end of the process cartridge 10K is provided a Waste
toner conveyance part 64K that extends from the drum clean
ing apparatus 6K to a Waste toner receiving part 72K of the
toner container 7K (not shoWn in FIG. 4). A bottom end of the
Waste toner conveyance part 64K communicates With the
drum cleaning apparatus 6K and a top end of the Waste toner
conveyance part 64K communicates With the Waste toner
receiving part 72K of the toner container 7K. In the inside of
the Waste toner conveyance part 64K, the endless Waste toner
from the toner supply port to the entire area in an axis direc
collecting belt 63K is provided, and is extended betWeen and
tion of the developing apparatus 4K, an agitator 43K that stirs
toner in the developing apparatus 4K, and the developing
roller 41K that is the toner carrying member. Further, a lamel
lation blade 45K, an extending end of Which is in contact With
Wound on a folloWing roller 65K and a driving roller 66K in
a tensioned state. On an outer circumferential surface of the
40
the developing roller 41K and Which makes thinner a toner
of the Waste toner collecting belt 63K have a Width the same
as a Width of the Waste toner collecting belt 63K, and tops of
layer that is carried by the developing roller 41K, and the
the protrusion parts 63aK have heights such that the top
toner supply roller 42K that is in contact With the developing
roller 41K and supplies toner to the developing roller 41K, are
provided.
45
The toner supply roller 42K is in contact With the develop
ing roller 41K, is rotated along With rotation of the developing
the bottom end of the Waste toner conveyance part 64K at an
50
supply roller 42K is coated by a formed material having cells,
thus, e?iciently takes in by causing the toner in the inside of
the developing apparatus 4K to adhere to the formed material,
and also, prevents deterioration of the toner otherWise occur
ring because of concentration of pres sure at a part at Which the
55
toner supply roller 42K is in contact With the developing
roller 41K. To the toner supply roller 42K, a voltage of normal
electri?cation polarity (negative polarity) of toner is applied
by the poWer source 110 as a voltage applying part. The
60
voltage is a negative voltage loWer than a voltage (negative
voltage) applied to the developing roller 41K, that is, a nega
end part of the process cartridge 10K, by a Waste toner con
veying member 62K. The Waste toner thus conveyed to the
bottom of the Waste toner conveyance part 64K is raked up by
the protrusion parts 6311K of the Waste toner collecting belt
63K. The Waste toner that has been thus raked up by the
protrusion parts 63aK is held, as shoWn in FIG. 4, in a space
S betWeen the protrusion parts 6311K and a bottom surface of
the Waste toner conveyance part 64K and is conveyed upWard
(in a direction indicated by an arroW B). After the Waste toner
is thus conveyed to an upper part of the Waste toner convey
ance part 64K by the Waste toner collecting belt 63K, the
Waste toner falls to a Waste toner receiving path (not shoWn).
The Waste toner thus having fallen to the Waste toner receiv
ing path is then conveyed to the Waste toner receiving part
tive voltage having an absolute value larger than an absolute
value of the negative voltage applied to the developing roller
41K. Thereby, at the part at Which the toner supply roller 42K
is in contact With the developing roller 41K, an electric ?eld
is generated. Friction electri?cation of the toner in the inside
surfaces of the protrusion parts 6311K touch Without gaps a
surface of the Waste toner conveyance part 64K facing the
Waste toner collecting belt 63K.
Toner removed from the photosensitive member 1K by the
drum cleaning apparatus 6K is, as Waste toner, conveyed to
roller 41K or is rotated in a rotation direction reverse or
counter to a rotation direction of the developing roller 41K,
and supplies toner that adheres to the toner supply roller 42K
to the toner developing roller 41K. The surface of the toner
Waste toner collecting belt 63K, protrusion parts 63aK are
formed at predetermined intervals. The protrusion parts 6311K
65
72K by a Waste toner collecting screW 73K (see FIG. 3). The
toner that has been thus received by the Waste toner receiving
part 72K is not used again for a developing purpose, and is
kept stored in the Waste toner receiving part 72K.
US 8,483,583 B2
9
10
The toner container 7K is provided detachably from the
the neW toner is supplied from the toner storage part 71K to
apparatus body of the developing apparatus 4K, and, after the
the developing apparatus 4K through the process described
neW toner in the toner storage part 71K runs out, the toner
above With reference to FIG. 3. Thus, the control part 90 and
the conveying member 71bK act as a toner supplying part.
Further, the ?oWability of the toner varies depending on tem
container 7K is removed from the apparatus body of the
developing apparatus 4K, and is replaced With another toner
perature and humidity conditions of the developing apparatus
container 7K in Which neW toner is held. At the same time, the
Waste toner stored in the Waste toner receiving part 72K of the
toner container 7K is also collected.
4K. Therefore, in a case Where the conveying member 71bK
is driven for a ?xed driving time period at any time, an amount
of the neW toner supplied to the developing apparatus 4K may
vary depending on the environmental conditions of the devel
Further, the developing apparatus 4K has a detecting Win
doW 46K made from transparent material and protruding
from a case of the developing apparatus 4K (see FIG. 5).
FIG. 5 shoWs a plan vieW of the developing apparatus 4K.
As shoWn in FIG. 5, a light receiving part 8111K and a light
emitting part 81bK of a transmission optical sensor 81K that
oping apparatus 4K. Therefore, it is preferable to change the
driving time period of the conveying member 71bK based on
detection results of temperature and humidity sensors (not
shoWn). When the transmission optical sensor 81K has
detected that the toner height in the developing apparatus 4K
is still less than the predetermined height value (or has
detected that the toner remaining amount in the developing
apparatus 4K is less than the predetermined toner amount
value) even after the toner is thus supplied, the control part 90
is a height detecting part are disposed to face one another to
sandWich the detecting WindoW 46K. The detecting WindoW
46K includes a holloW part (not shoWn), and the holloW part
communicates With the inside of the developing apparatus
4K. In a case Where the height of the toner held in the devel
oping apparatus 4K is higher than the detecting WindoW 46K,
20
displays an indication of “toner en ” on a display panel (not
the holloW part of the detecting WindoW 46K is ?lled With the
shoWn) of the printer 100, and thus urges the user to replace
toner, and light emitted by the light emitting part 81bK of the
the toner container 7K.
transmission optical sensor 81K is blocked by the toner.
The above-mentioned drum cleaning apparatus 6K
Thereby, the light receiving part 8111K does not detect light,
includes a cleaning blade 61K, an extending end of Which is
in contact With the surface of the photosensitive member 1K
and Which is made of an elastic body, and the Waste toner
conveying member 62K for conveying the Waste toner
removed by the cleaning blade 61K from the surface of the
photosensitive member 1K to the Waste toner conveyance part
and an output value of the light receiving part 8111K is
approximately Zero. After the toner in the developing appa
ratus 4K is consumed, the height of the toner in the develop
25
ing apparatus 4K I loWered, and the height of the toner in the
developing apparatus 4K becomes loWer than the position of
the detecting WindoW 46K. As a result, since there is no toner
30
in the holloW part of the detecting WindoW 46K, the light
The process cartridge 10K has been described above With
reference to FIGS. 3, 4 and 5. Each of the process cartridges
10Y, 10M and 100 for the other colors Y, M and C, respec
emitted by the light emitting part 81bK is transmitted by the
detecting WindoW 46K and thus is received by the light
receiving part 8111K. As a result, a predetermined output value
is obtained from the light receiving part 8111K, and thus, it is
64K (see FIG. 4).
tively, has the same con?guration as that of the process car
detected that the height of the toner held in the developing
tridge 10K for the color K, andY, M and C toner images are
formed on the surfaces of the photosensitive members 1Y, 1M
apparatus 4K becomes equal to or less than a predetermined
and 1C, respectively, by the same processes. Therefore, dupli
height value. Thus, the control part 90 detects the toner
remaining amount in the developing apparatus 4K. That is,
cate descriptions are omitted.
As shoWn in FIG. 2A, a transfer unit 3 0 that is a transferring
part and includes an intermediate transfer belt 15 that is an
according to the present embodiment, the transmission opti
35
40
endless moving member is provided beloW in a vertical direc
tion of the process cartridges 10Y, 10M, 10C and 10K. The
cal sensor 81K that is the height detecting part and the control
part 90 act as a remaining amount detecting part that detects
the toner remaining amount in the developing apparatus 4K.
According to the present embodiment, the transmission opti
cal sensor 81K is used to detect the toner remaining amount in
45
the developing apparatus 4K based on the height of the toner
held in the developing apparatus 4K. HoWever, instead, a
pieZoelectric sensor or such may be provided in the inside of
the developing apparatus 4K, and the toner remaining amount
may be detected directly by using the pieZoelectric sensor or
such provided in the inside of the developing apparatus 4K.
The control part 90 is, for example, a computer. Further, When
the control part 90 has detected that the toner height in the
developing apparatus 4K becomes less than the predeter
mined height value by means of the transmission optical
sensor 81K, the control part 90 may start counting dots
included in an image to be output by using the process car
tridge 10K, and the control part 90 may estimate a toner
consumption amount from the number of dots obtained from
the counting. Then, after the number of dots (estimated toner
consumption amount) has become a predetermined number
value, the control part 90 may determine that the toner
remaining amount in the developing apparatus 4K becomes
less than a predetermined toner amount value.
The control part 90 drives and rotates the conveying mem
ber 71bK (see FIG. 3) after the toner remaining amount
becomes less than the predetermined toner amount value, and
intermediate transfer belt 15 is extended betWeen and Wound
on a tension roller 23 and a driving and secondary transfer
facing roller 21 in a tensioned state, and is rotated in a direc
tion of an arroW C shoWn in FIG. 2A, as the driving and
secondary transfer facing roller 21 is driven by a driving
motor (not shoWn) mounted in an extending direction of the
driving and secondary transfer facing roller 21. The transfer
50
unit 30 includes, in addition to the intermediate transfer belt
15, four primary transfer rollers 5Y, 5M, 5C and 5K, and a belt
cleaning apparatus 33. The transfer unit 30 is con?gured as
being detachable from the body of the printer 100, and is
55
con?gured such that consumable parts can be replaced at a
time.
In this con?guration, in a case Where image forming is
carried out in a negative positive Way (in Which an absolute
value of an electrical potential at an exposed part is loWer than
an absolute value of an electrical potential at a non-exposed
60
part, and toner adheres to the exposedpart), the surfaces of the
respective photosensitive members 1Y, 1M, 1C and 1K are
uniformly electri?ed by the respective electrifying appara
tuses 2Y, 2M, 2C and 2K in the negative polarity. Next, from
an exposure apparatus 130 as a latent image forming part
65
disposed above in the vertical direction of the photosensitive
members 1Y, 1M, 1C and 1K, light beams 3Y, 3M, 3C and 3K
according to given image information are applied to the
US 8,483,583 B2
11
12
respective photosensitive members 1Y, 1M, 1C and 1K, and
53, the pivoting member 51 slightly rotates clockWise in
thereby, latent images for the respective colors are formed on
FIGS. 6A, 6B. In a case Where a monochrome image is to be
the respective photosensitive members 1Y, 1M, 1C and 1K.
formed, as being driven by the solenoid 53, the pivoting
member 51 is slightly rotated clockwise. By the rotating, as
shoWn in FIG. 6B, the intermediate transfer belt 15 is
removed from the photo sensitive members 1Y, 1C and 1M for
the colors Y, C and M. Then, only the process cartridge 10K
As the exposure apparatus 130, a laser beam scanner using
laser diodes or such may be used. Next, as a result of devel
oping biases in negative polarity having absolute values
larger than the electrical potentials at the exposed parts being
applied to the developing rollers 41Y, 41M, 41C and 41K of
the respective developing apparatuses 4Y, 4M, 4C and 4K
for the color K is driven from among the four process car
and are made to adhere to the latent images. Thereby, toner
images corresponding to the latent images are formed on the
tridges 10Y, 10M, 10C and 10K, and a monochrome image is
formed. Thus, in cases of forming monochrome images, it is
possible to avoid uselessly driving the process cartridges for
the colorsY, C and M, and it is possible to prevent the process
cartridges for the colors Y, C and M from being expended.
photosensitive members 1Y, 1M, 1C and 1K.
The toner images of the respective colors thus developed
by the developing apparatuses 4Y, 4M, 4C and 4K, respec
moving direction of the intermediate transfer belt 51 With
respect to the process cartridge 10K of the color K, a re?ec
from the poWer source 110, the toners carried by the devel
oping rollers 41Y, 41M, 41C and 41K are moved to the latent
images on the photosensitive members 1Y, 1M, 1C and 1K,
Further, as shoWn in FIG. 2A, in a doWnstream side in the
tively, are primarily transferred to the intermediate transfer
belt 15 as an intermediate transfer member, in such a manner
that the respective toner images are superposed to form a
color image. The toners not having been transferred to the
intermediate transfer belt 15 and remaining after the transfer
20
FIG. 7 shoWs a general con?guration of the re?ection opti
cal sensor 150. The re?ection optical sensor 150 includes a
light emitting device (LED: light emitting diode) 151, a
process on the respective photosensitive members 1Y, 1M, 1C
specular re?ection light receiving device 152 made of a pho
and 1K are removed from the surfaces of the photosensitive
members 1Y, 1M, 1C and 1K by the cleaning blades 61Y,
61M, 61C and 61K of the respective cleaning apparatuses 6Y,
tion optical sensor 150 is provided to detect a toner amount of
toner adhering to the surface of the intermediate transfer belt
15.
25
6M, 6C and 6K.
totransistor that receives specular re?ection light and a dif
fuse re?ection light receiving device 153 made of a pho
totransistor that receives diffuse light. The specular re?ection
Further, a paper supply cassette (not shoWn) is provided
light receiving device 152 is disposed symmetrically With the
beloW in the vertical direction of the intermediate transfer belt
15 in the printer 1 00. Transfer paper fed from the paper supply
cassette is conveyed by a conveyance belt (not shoWn) as
light emitting device 151 With respect to a vertical surface. An
30
being guided by a conveyance guide (not shown), and is sent
to a temporary stopping position at Which a registration roller
(not shoWn) is provided. Then, at a predetermined timing, the
transfer paper is supplied by the registration roller to a sec
ondary transfer part betWeen a part of the intermediate trans
fer belt 15 at Which the intermediate transfer belt 15 is Wound
on the secondary transfer facing roller 21 and a secondary
35
formed on the intermediate transfer belt 15 is secondarily
transferred to the transfer paper, and the color image is thus
formed on the transfer paper. The color image (toner images)
formed on the transfer paper is ?xed by a ?xing unit 26, and
after that, the transfer paper is ejected to a paper ejecting tray
detect the toner adhesion amount on the intermediate transfer
belt 15 is so smooth as to behave as a mirror surface, and
40
and then being re?ected by the surface of the intermediate
adheres to the intermediate transfer belt 15 has a coarse sur
45
(not shoWn). Further, the toners remaining on the intermedi
sible to estimate the toner adhesion amount by estimating a
Which no toner adheres (bare or exposed surface area) on the
cleaning apparatus 33, through a conveyance part (not
55
Further, the printer 100 has a contact/apart mechanism 50
as a contact/apart part Which causes the intermediate transfer
belt 15 to come into contact With and be removed from the
photosensitive members 1Y, 1M and 1C.
FIGS. 6A and 6B shoW a general con?guration of the
contact/ apart mechanism 50.
As shoWn in FIGS. 6A and 6B, the contact/apart mecha
nism 50 has a pivoting member 51 that supports the primary
transfer rollers 5Y, 5M and 5C, one end of the pivoting mem
ber 51 being supported in a pivotable manner by a rotation
shaft 52. The other end of the pivoting member 51 is sup
ported by a solenoid 53, and, as being driven by the solenoid
face, and therefore, diffuse re?ection light becomes dominant
over specular re?ection light. Accordingly, by measuring a
ratio betWeen specular re?ection light and diffuse re?ection
light re?ected by the intermediate transfer belt 15, it is pos
50 ratio betWeen an area in Which toner adheres and an area in
the toner container 7K) of the toner container 7Y from the belt
shoWn).
therefore, specular re?ection light is dominant in light
obtained from being emitted by the light emitting device 151
transfer belt 15. On the other hand, a part at Which toner
ate transfer belt 15 after the secondary transfer process are
removed by the belt cleaning apparatus 33. The toners thus
removed by the belt cleaning apparatus 33 are, as Waste
toners, conveyed to a Waste toner receiving part (not shoWn
and corresponding to the Waste toner receiving part 72K of
as much as possible. The diffuse re?ection light receiving
device 153 is disposed on the opposite side of the specular
re?ection light receiving device 152 With respect to the light
emitting device 151.
By using the re?ection optical sensor 150, it is possible to
belt 15. Speci?cally, the surface of the intermediate transfer
transfer roller 22. Then, as a result of a predetermined sec
ondary bias being applied to the secondary transfer roller 22
by the poWer source 110, the color image (toner images)
aperture 154 is provided in front of the specular re?ection
light receiving device 152 for avoiding receiving diffuse light
60
intermediate transfer belt 15. Mainly, the specular re?ection
light receiving device 152 is used for detecting a toner adhe
sion amount of K toner and detecting loW (small) toner adhe
sion amounts of color toners (Y, M and C toners). On the other
hand, the diffuse re?ection light receiving device 153 is used
for detecting high (large) toner adhesion amounts of color
toners (Y, M and C toners).
Next, toner supply control operation Will be described.
As mentioned above, for the sake of convenience, descrip
tion is made only for the developing apparatus 4K for
example. HoWever, also to the other developing apparatuses
4Y, 4M and 4C, the same description is applicable, and dupli
65
cate description is omitted. As shoWn in FIG. 8, When the
control part 90 has detected based on the output signal of the
transmission optical sensor 81K (see FIG. 5) that the toner
remaining amount in the developing apparatus 4K is less than
US 8,483,583 B2
13
14
the predetermined toner amount value (step S1 YES), the
control part 90 carries out a fog detecting process (step S2).
When the fog detecting process is thus carried out, a blank
paper image as a fog detecting image is formed on the inter
fore, in the memory 95 of the printer 100, a developing
apparatus operational status obtaining table in Which the run
ning distance and the fog amount for When the neW toner is
0% are associated With one another is stored, and the opera
tional status of the developing apparatus 4K is obtained from
mediate transfer belt 15. Speci?cally, in a case Where the
the developing apparatus operational status obtaining table
toner remaining amount in the developing apparatus 4K for
the color K becomes less than the predetermined toner
amount value, the electrifying apparatus 2K of the process
cartridge 10K including the developing apparatus 4K uni
formly electri?es the surface of the photosensitive member
1K, no exposure is carried out by the exposure apparatus 130,
and the predetermined developing bias is applied to the devel
oping roller 41K. Thereby, the blank paper image is formed
10
Speci?cally, ?rst, a pre-toner-supply operation of supplying
10 g of neW toner to the developing apparatus 4K is carried
out (step S4). In the present embodiment, as shoWn in FIG. 3,
it is possible to control, With relatively high accuracy, a neW
toner supply amount to the developing apparatus 4K by con
on the photosensitive member 1K. In a case Where deteriora
tion of old toner remaining in the developing apparatus 4K is
minor, and the old toner is suf?ciently electri?ed, the toner
hardly moves to the photosensitive member 1K, and fog
trolling the driving time period of the conveying member
71bK in the toner storage part 71K. Further, as described
hardly occurs. On the other hand, in a case Where the toner in
the developing apparatus 4K is deteriorated, and the electri
?cation amount in the toner is small, the force operating on
the toner such that the toner is prevented from moving from
the developing roller 41K because of the electric ?eld
betWeen the developing roller 41K and the photosensitive
member 1K becomes Weaker. Therefore, the deteriorated
Weak-electri?ed toner adheres to the photosensitive member
1K. As a result, fog in the blank paper image becomes Worse.
Then, the blank paper image is transferred to the intermediate
transfer belt 15, and the blank paper image is then detected by
the re?ection optical sensor 150 disposed on the doWnstream
side in the moving direction of the intermediate transfer belt
15 With respect to the process cartridge 10K for the color K as
20
very high accuracy. In the present embodiment, by driving the
conveying member 71bK for 30 seconds, it is possible to
25
30
fog amount vary in monotonously decreasing (i.e., increasing
in fog amount) manners approximately linearly. Therefore, in
35
in the developing apparatus 4K after the pre-toner-supply
y:ax+b), and thus, it is possible to easily and precisely obtain
40
since toner hardly adheres to the intermediate transfer belt 15.
in the example ofFIG. 1) as shoWn in FIG. 1, and thus, it is not
possible to precisely obtain a ratio of the neW toner.
45
refection light receiving device 153 increases, since much
toner (Weak-electri?ed toner) adheres to the intermediate
transfer belt 15. In the present embodiment, fog is detected
based on the output value of the specular light receiving
normal electri?cation polarity (negative polarity). After the
toner in the developing apparatus 4K is thus stirred for 30
seconds, the fog detecting process the same as the above (step
device 152 and the toner adhesion amount are associated With
one another is stored in a memory 95 of a non-volatile type
(see FIG. 2B). Then, based on the output value of the specular
55
sion table, a fog amount (adhesion amount) is obtained. Fur
ther, generally speaking, the adhesion amount conversion
S2) is carried out, and the fog amount is detected (step S6).
Next, the old toner amount remaining in the developing appa
ratus 4K is obtained (step S7) from the fog amount detected in
step S6, the operational status of the developing apparatus 4k
since the toner Was supplied the last time obtained in step S3
and the neW toner amount (10 g) supplied in the pre-toner
table for the color K and the adhesion amount conversion
table for the color toners (Y, M and C colors) are prepared
supply operation (step S4). Speci?cally, in the memory 95 of
60
the printer 100 is stored a neW toner ratio obtaining table, in
Which table the operational status of the developing apparatus
4K and the linear approximation equation (y:ax+b), in Which
Next, based on the thus-obtained fog amount, an opera
tional status (running distance) of the developing apparatus
4K since the supplying of toner the last time is obtained (step
S3). As shoWn in FIG. 1, it is seen that, the fog amount for
When the neW toner is 0%, i.e., all the toner in the developing
apparatus 4K is old toner, varies for the respective running
distances (5 km and 10 km in the example of FIG. 1). There
Next, the toner in the developing apparatus 4K is stirred for
30 seconds (step S5). Thereby, the deteriorated old toner and
the neW toner rub together in the developing apparatus 4K,
and thereby, the old toner may become Weakly electri?ed, or
may become electri?ed to positive polarity reverse to the
50
table in Which the output value of the specular light receiving
separately.
a ratio of the neW toner in the developing apparatus 4K after
the pre-toner-supply operation. On the other hand, in a case
Where a ratio of neW toner in the developing apparatus 4K is
50:20%, the fog amounts have peaks (local minimum values
On the other hand, When the blank paper image having
remarkable fog is detected by the re?ection optical sensor
150, the output value of the specular refection light receiving
light receiving device 152 and the adhesion amount conver
this condition, it is possible to obtain a ratio of the neW toner
operation by using a linear approximation equation (i.e.,
specular re?ection light receiving device 152 is approxi
device 152. Speci?cally, an adhesion amount conversion
toner in the developing apparatus 4K is equal to or less than
30% (around the left end of FIG. 1), the relationships betWeen
the ratio of neW toner in the developing apparatus 4K and the
mately maximum and the output value of the diffuse refection
device 152 decreases and the output value of the diffuse
supply 10 g of neW toner to the developing apparatus 4K. The
neW toner supply amount in the pre-toner- supply operation is
determined such that a ratio of neW toner in the developing
apparatus 4K becomes equal to or less than 30%. This is
because, as shoWn in FIG. 1, in a case Where the ratio of neW
based on the detection result of the re?ection optical sensor
light receiving device 153 becomes approximately minimum,
above, in the present embodiment, such control that the driv
ing time is changed according to the temperature and humid
ity conditions and/or toner ?oWability variation due to toner
deterioration can be carried out. Therefore, it is possible to
supply 10 g of neW toner to the developing apparatus 4K With
shoWn in FIG. 2A, and the control part 90 detects the fog
150. That is, the re?ection optical sensor 150 and the control
part 90 act as a fog detecting part.
When the blank paper image having a little fog is detected
by the re?ection optical sensor 150, the output value of the
and the detected fog amount.
After the operational status of the developing apparatus 4K
is thus obtained, a process of obtaining the old toner amount
remaining in the developing apparatus 4K is carried out.
equation the ratio of neW toner and the fog amount are asso
ciated With each other, are associated With each other. Then,
65
from the operational status of the developing apparatus 4K
obtained in step S3 and the neW toner ratio obtaining table, the
corresponding linear approximation equation is obtained.
US 8,483,583 B2
15
16
Then, based on the determined linear approximation equation
end” on the display panel of the printer 100, and thus, urges
and the detected fog amount, the ratio of neW toner in the
developing apparatus 4K is obtained. Next, because the neW
toner amount supplied at the time of the pre-toner-supply
operation is knoWn as 10 g, the old toner amount remaining in
the user to replace the toner container 7K (step S12).
Thus, according to the present embodiment, it is possible to
precisely determine the old toner amount remaining in the
developing apparatus 4K, and therefore, it is possible to sup
the developing apparatus 4K is obtained from the obtained
ply the minimum necessary amount of neW toner to be able to
ratio of neW toner in the developing apparatus 4K and the neW
control fog occurring after the neW toner is supplied to the
alloWable level. Thus, it is not necessary to supply a large
toner amount (10 g) supplied in the pre-toner-supply opera
tion.
After the old toner amount remaining in the developing
apparatus 4K is thus obtained in step S7, a neW toner amount
amount of neW toner to prevent fog occurring after neW toner
is supplied, and it is possible to avoid an increase in torque of
the agitator 43K and/or the toner supply roller 42K. Further,
it is possible to prevent toner packing from occurring.
Further, according to the present embodiment, the process
starting from step S2 of FIG. 8 of the toner supply control
operation for supplying neW toner in the developing appara
Xg to be supplied to the developing apparatus 4K is deter
mined (step S8). Speci?cally, as shoWn in FIG. 1, the neW
toner amount Xg is determined such that a ratio of neW toner
in the developing apparatus 4K after the neW toner amount Xg
is supplied becomes such that fog is equal to or less than an
tus 4K is carried out after it is detected in step S1 by the
remaining amount detecting part including the transmission
alloWable level. For example, a ratio of neW toner such that
fog becomes the alloWable level for a condition of the longest
optical sensor 81K and the control part 90 that the toner
running distance expectable in an ordinary operation condi
prescribed value. Instead, a table in Which the operational
remaining amount in the developing apparatus 4K becomes
less than the predetermined toner amount value. Thus, the
process starting from step S2 of FIG. 8 of the toner supply
control operation for supplying neW toner in the developing
status of the developing apparatus 4K and the ratio of neW
toner such that fog becomes in the alloWable level are asso
developing apparatus 4K has been suf?ciently reduced.
tion may be prescribed, and the neW toner amount Xg may be
determined such that the ratio of neW toner becomes the
ciated With each other may be stored in the memory 95, and
the ratio of neW toner such that fog becomes in the alloWable
level may be determined from the operational status of the
20
apparatus 4K is carried out When the old toner amount in the
25
Therefore, it is possible to reduce the necessary neW toner
supply amount determined in step S8 of FIG. 8 to cause the
ratio of the neW toner to be such that fog can be reduced to be
equal to or less than the alloWable level. Thus, it is possible to
prevent the toner amount in the developing apparatus 4K after
30
neW toner is supplied from becoming much. Further, since
developing apparatus and the stored table. Then, the neW
toner amount Xg is determined based on the determined ratio
of neW toner and the old toner amount obtained in step S7.
For example, When the neW toner amount in the developing
supplying neW toner is not carried out until the toner amount
apparatus 4K after the pre-toner-supply operation has been
obtained as 25% in step S7, the old toner amount remaining in
the developing apparatus 4K is obtained as 30 g in step S7
since the neW toner amount supplied in the pre-toner-supply
operation is 10 g as mentioned above, and thus, in the devel
in the developing apparatus 4K is reduced to be less than the
predetermined toner amount, the process starting from step
S2 of FIG. 8 of the toner supply control operation for supply
35
oping apparatus 4K after the pre-toner-supply operation the
neW toner is 10 g accordingly. That is, since 10 g corresponds
to 25%, the remaining 75% (old toner) corresponds to 30 g
accordingly. Then, in a case Where the ratio of neW toner in the
developing apparatus 4K after the neW toner amount Xg is
supplied is determined as 70% in step S8, the toner amount
Xg:70 [g] is thus to be supplied. This is because the old toner
in the developing apparatus 4K is 30 g as mentioned above,
and therefore, 70% of neW toner in the developing apparatus
40
of the other developing apparatuses 4Y, 4M and 4C for the
other colors Y, M and C, and duplicate description therefor
45
Will be omitted.
In the above-mentioned con?guration, the process starting
from step S2 of FIG. 8 of the toner supply control operation
for supplying neW toner in the developing apparatus 4K is
supplied (that is, 70 [g]/(30 [g] +70 [g]):70/l00:0.70). Then,
carried out after it is determined in step S1 that the toner
50
After the neW toner amount Xg is thus determined in step
S8, the control part 90 controls driving of the conveying
remaining in the developing apparatus 4K in step S7.
Description has been made for the developing apparatus
4K for the color K as an example. As mentioned above, the
same toner supply control of FIG. 8 is carried out also for each
4K can be achieved as a result of 70 g of neW toner being
since 10 g of neW toner has been already supplied in the
pre-toner-supply operation (step S4), 60 g of neW toner is to
be further supplied, Which is a difference betWeen the above
mentioned target value 70 g and the above-mentioned
already-supplied value 10 g. Thus, the neW toner supply
amount Xg is 60 g.
ing neW toner in the developing apparatus 4K is carried out
after the deterioration of the old toner remaining in the devel
oping apparatus 4K progresses to a certain degree. As a result,
it is possible to precisely determine the old toner amount
55
remaining amount in the developing apparatus 4K becomes
less than the predetermined toner amount. HoWever, instead,
for example, the process starting from step S2 of FIG. 8 of the
toner supply control operation for supplying neW toner in the
developing apparatus 4K may be carried out after a predeter
mined time period has elapsed.
member 71bK, and supplies the determined neW toner
amount Xg of neW toner to the developing apparatus 4K (step
Further, a gloss level on the surface of the intermediate
transfer belt 15 may vary as a result of the surface of the
S9).
intermediate transfer belt 15 being deteriorated because of
having been used for a long time period. When the gloss level
After the neW toner is thus supplied to the developing
apparatus 4K in step S9, the toner in the developing apparatus
4K is stirred for 30 seconds (step S10), and the toner remain
60
on the surface of the intermediate transfer belt 15 varies, the
output value of the re?ection optical sensor 150 varies, and
precise fog detection may not be able to be carried out. There
fore, correction of the detection result of the fog detection
may be carried out by using a detection result of the re?ection
65
optical sensor 150 obtained When no toner has adhered to the
ing amount in the developing apparatus 4K is detected by
using the transmission optical sensor 81K (step S11). When
the toner remaining amount in the developing apparatus 4K is
still less than a threshold (step S11 YES), Which means that
there is no neW toner left in the toner storage part 71K,
therefore the control part 90 displays the indication of “toner
surface of the intermediate transfer belt 15. Speci?cally, for a
case of the color K, after a blank paper image is developed on
US 8,483,583 B2
17
18
the surface of the photosensitive member 1K, the developing
and C described above. The second contact/apart mechanism
may include, for example, a supporting member that supports
the primary transfer roller 5K for the color K and moves in
roller 41K is removed from the photosensitive member 1K.
Next, the blank paper image formed on the intermediate
transfer belt 15 is detected by means of the re?ection optical
directions such that the supporting member comes into con
photosensitive member 1K. Therefore, no toner has adhered
tact With and is removed from the photosensitive member 1K
for the color K; and a moving part such as a solenoid Which
moves the supporting member in directions such that the
supporting member comes into contact With and is removed
from the photosensitive member 1K for the color K.
Further, a second re?ection optical sensor (not shoWn) may
be provided at a position facing an image not-forming area of
the intermediate transfer belt 15, and the fog detection result
of the re?ection optical sensor 150 may be corrected by using
the output value of the second re?ection optical sensor. Also
to the area on the intermediate transfer belt 15. Accordingly,
by calculating a difference value (V sp_dif —Vsp_dif)
by detecting in the area on the intermediate transferbelt 15 by
means of the re?ection optical sensor 150, it is possible to
precisely detect a variation in the gloss level on the interme
diate transfer belt 15. Then, by calculating a difference value
(Vsp_dif-Vsp_dif) betWeen a detection value Vsp_dif
obtained When the blank paper image has been detected and a
detection value Vsp_dif obtained When the above-mentioned
betWeen a value Vsp_dif obtained When the second re?ection
optical sensor has detected in the image not-forming area at
an edge part of the intermediate transfer belt 15 and a value
Vsp_dif obtained When the re?ection optical sensor 150 has
sensor 150. Next, the re?ection optical sensor 150 is used to
detect in an area on the intermediate transfer belt 15 Where the
intermediate transfer belt 15 comes into contact With an area
on the photo sensitive member 1K Where the developing roller
41K has been thus removed from the photosensitive member
1K. The area on the intermediate transfer belt 15 is the area
Where the intermediate transfer belt 15 comes into contact
With the area on the photosensitive member 1K Where the
developing roller 41K does not come into contact With the
20
area on the intermediate transfer belt 15 coming into contact
With the area on the photosensitive member 1K Where the
developing roller 41K has been removed from the photosen
sitive member 1K has been detected, it is possible to precisely
detect, by using the absolute value of the difference value
(Vsp_dif‘ —Vsp_dif), the fog amount from Which the variation
25
in the gloss level on the intermediate transfer belt 15 has been
removed. Thus, it is possible to carry out precise fog detection
30
through aging.
In a case of each of theY, M and C colors, in fog detecting
operation, after a blank paper image is formed on the inter
mediate transfer belt 15, the intermediate transfer belt 15 is
removed from the photosensitive members 1Y, 1M and 1C by
35
means of the contact/apart mechanism 50 described above
With reference to FIGS. 6A and 6B. Then, after the blank
paper image thus formed on the intermediate transfer belt 15
is detected, an area on the intermediate transfer belt 15 is
detected, Which area on the intermediate transfer belt 15 is the
40
area having moved and come Without coming into contact
Accordingly, by detecting in the area on the intermediate
transfer belt 15 by means of the re?ection optical sensor 150,
it is possible to precisely detect a variation in the gloss level
on the intermediate transfer belt 15. Then, by calculating a
difference value (Vsp_dif-Vsp_dif) betWeen a detection
45
and thus deterioration of the old toner remaining in the devel
oping apparatus is minor, the neW toner amount supplied in
the pre-toner-supply operation may be made larger. In con
trast thereto, in a case Where the operating time period (run
deterioration of the old toner remaining in the developing
apparatus has progressed, the neW toner amount supplied in
the pre-toner-supply operation may be made smaller. This is
because in the case Where the deterioration of the old toner is
minor, fog hardly occurs, and therefore, the toner adhesion
50
detected and a detection value Vsp_dif obtained When the
above-mentioned area on the intermediate transfer belt 15
55
amount obtained When a blank paper image has been formed
is almost Zero. In such a case Where fog hardly occurs, the
output value of the re?ection optical sensor obtained When a
blank paper image has been detected falls Within a range of
possible error, and thus, it may not be possible to carry out
precise fog detection. As shoWn in FIG. 1, fog becomes Worse
(i.e., fog increases) as the ratio of neW toner increases in a
range Where the ratio of neW toner is up to around 50%.
detected, it is possible to precisely detect, by using the abso
Therefore, if the neW toner amount supplied in the pre-toner
supply operation is small in a case Where deterioration of the
old toner is minor, the ratio of neW toner in the developing
lute value of the difference value (Vsp_dif-Vsp_dif), the fog
amount from Which the variation in the gloss level on the
intermediate transfer belt 15 has been removed. Thus, it is
toner-supply operation is carried out, a blank paper image is
formed, fog is detected based on the fog detection result, and
the operational status of the developing apparatus is deter
mined. HoWever, it is also possible to determine the opera
tional status of the developing apparatus from the driving time
period of the developing roller or such, instead.
Further, in the above-mentioned con?guration, the neW
toner amount supplied to the developing apparatus in the
pre-toner-supply operation is 10 g. HoWever, the neW toner
amount supplied in the pre-toner-supply operation may be
changed based on the operational status of the developing
apparatus. Speci?cally, in a case Where the operating time
ning distance) of the developing apparatus is long and thus
value Vsp_dif obtained When the blank paper image has been
Where the intermediate transfer belt 15 has been removed
from the photosensitive members 1Y, 1M and 1C has been
in the gloss level on the intermediate transfer belt 15 has been
removed.
In the above-mentioned con?guration, before the pre
period (running distance) of the developing apparatus is short
With the photosensitive member 1Y, 1M and 1C after passing
the belt cleaning apparatus 33. The area on the intermediate
transfer belt 15 thus has not come into contact With the pho
tosensitive member 1Y, 1M and 1C, and therefore, no toner
has adhered to the area on the intermediate transfer belt 15.
detected in the blank paper image, it is possible to precisely
detect, by using the absolute value of the difference value
(V sp_dif‘ —Vsp_dif), the fog amount from Which the variation
60
apparatus is small, fog hardly occurs, and thus, precise fog
possible to carry out precise fog detection through aging.
Further, a second contact/apart mechanism (not shoWn)
detection may not be able to be carried out. Therefore, in the
may be provided such that the intermediate transfer belt 15
short and deterioration of the old toner remaining in the
developing apparatus is minor, the neW toner amount sup
case Where the operating time period (running distance) is
can be caused to come into contact With and be removed from
the photosensitive member 1K for the color K, and a variation
in the gloss level on the intermediate transfer belt 15 may be
detected in the same method as that for each of the colorsY, M
65
plied in the pre-toner-supply operation is made larger, and
thus, the ratio of neW toner in the developing apparatus is
made larger. Thereby, fog occurs to a certain degree When a
US 8,483,583 B2
19
20
blank paper image has been formed, and toner adheres to the
intermediate transfer belt to a certain degree. As a result, the
has been already supplied in the pre-toner-supply operation
output of the re?ection optical sensor can be obtained to a
S8, S9) is 150 g (i.e., 160 [g]—l0 [g]:l50 [g]). At this time,
assuming that the capacity of the developing apparatus is 100
g, only 50 g can be added (i.e., 100 [g]—(40 [g]+l0 [g]):50
as mentioned above, neW toner to be further supplied (steps
certain degree, and thus, it is possible to detect fog precisely.
On the other hand, in the case Where the operating time
period (running distance) is long, and therefore, deterioration
progressed, fog occurs to a certain degree even When the ratio
of neW toner in the developing apparatus is small. Therefore,
the output of the re?ection optical sensor can be obtained to a
[g]). If 50 g of neW toner is added (step S9), the resulting total
amount of neW toner becomes 60 g (:10 [g]+50 [g]) that is
much smaller than the above-mentioned required amount of
160 g, and thus, fog becomes seriously Worse. Therefore, in a
case Where the resulting toner amount in the developing appa
certain degree, and thus, it is possible to detect fog precisely.
ratus Would exceed the capacity of the developing apparatus
Accordingly, in the case Where the operating time period
if the neW toner supply amount Xg determined in step S8 of
FIG. 8 is supplied, a toner ejecting process described beloW
may be carried out.
When the toner ejecting process is carried out, in an
of the old toner remaining in the developing apparatus has
(running distance) of the developing apparatus is long, the
neW toner amount supplied in the pre-toner-supply operation
is made smaller. For example, in a case Where the operating
time period of the developing apparatus is longer than an
upper limit value, the neW toner amount supplied in the pre
example of the color K, the electrifying apparatus 2K uni
formly electri?es the surface of the photosensitive member
toner-supply operation may be made to be 10 g; in a case
Where the operating time period of the developing apparatus
is shorter than a loWer limit value, the neW toner amount
20
1K, and the exposure apparatus 130 exposes the entire surface
of the photosensitive member 1K. Thereby, the old toner
remaining in the developing apparatus 4K adheres to the
supplied in the pre-toner-supply operation may be made to be
entire area of an image forming area of the photosensitive
20 g; and in a case Where the operating time period of the
developing apparatus is equal to or shorter than the upper
limit value and equal to or longer than the loWer limit value,
the neW toner amount supplied in the pre-toner-supply opera
tion may be made to be 15 g.
member 1K, and thus, it is possible to effectively eject the
toner remaining in the developing apparatus 4K to the pho
25
removed by the belt cleaning apparatus 33 from the interme
Further, in a case Where a certain amount of neW toner has
been supplied in the pre-toner-supply operation, the fog level
obtained after the pre-toner-supply operation is the alloWable
level and the toner remaining amount in the developing appa
ratus obtained by using the transmission optical sensor is
equal to or more than a threshold, the process including and
after step S7 of the toner supply control operation of FIG. 8
may not be carried out and the toner supply control operation
may be terminated. Thereby, it is possible to shorten the time
30
conveyance part from the belt cleaning apparatus 33. It is
noted that, at this time, the secondary transfer roller 21 is
35
caused to be apart from the intermediate transfer belt 15.
Further, such a control method may be used instead that the
40
the surface of the photosensitive member 1K is not electri?ed,
and the old toner remaining in the developing apparatus 4K is
ejected. In this control method, the electri?cation electric
potential on the surface of the photosensitive member 1K is
voltage applied to the electrifying apparatus 2K is turned off,
apparatus. On the other hand, in a case Where the fog level
remaining amount in the developing apparatus obtained by
using the transmission optical sensor is equal to or less than
the threshold, the process including and after step S7 of the
toner supply control operation of FIG. 8 is carried out, and a
certain amount of neW toner is supplied to the developing
Zero and the predetermined developing bias of negative polar
ity is applied to the developing roller 41K. Therefore,
betWeen the photosensitive member 1K and the developing
roller 41K, toner of negative polarity on the developing roller
45
apparatus.
Further, in a case Where the ratio of neW toner after the
pre-toner-supply operation is small, a large amount of neW
toner is to be added for the purpose of causing fog to be equal
to or less (better) than the alloWable level. In particular, in a
50
case Where the operating time period (running distance) of the
developing apparatus is long, the ratio of neW toner required
for causing fog to be less (better) than the alloWable level
becomes larger, and thus, more amount of neW toner is to be
supplied. As a result, there may be a case Where if neW toner
diate transfer belt 15. Then, the toner is conveyed to the Waste
toner receiving part (corresponding to the Waste toner receiv
ing part 72K shoWn in FIG. 3 in the example of color K) of the
toner container 7Y of the color Y as Waste toner by the
period required for the toner supply control operation of FIG.
8, and it is possible to shorten doWntime of the developing
obtained after the pre-toner-supply operation is equal to or
more (Worse) than the alloWable level, and/or the toner
tosensitive member 1K. The old toner thus having been
ejected to the surface of the photosensitive member 1K is
transferred to the intermediate transfer belt 15, and is
41K electrostatically moves to the photosensitive member
1K. Thus, also in this control method, it is possible that the old
toner remaining in the developing apparatus 4K adheres to the
entire surface of the image forming area of the photo sensitive
member 1K. Further, in the case Where the control method is
used, it is not necessary to expose the surface of the photo
sensitive member 1K for a long time by the exposure appa
ratus 130, and it is advantageous that deterioration of the
photosensitive member 1K because of light-induced fatigue
can be avoided.
55
Further, such a control method may be used instead that at
a time of carrying out the toner ejecting process, the poWer
source 110 is controlled so that such a voltage is applied to the
toner supply roller 42K that an absolute value of the voltage
applied to the toner supply roller 42K becomes larger, and an
60
obtained as 40 g (step S7). In this case, in a case Where the
electric potential difference betWeen the developing roller
41K and the toner supply roller 42K becomes larger. Thereby,
the old toner remaining in the developing apparatus 4K easily
ratio of neW toner required for causing fog to be equal to or
less (better) than the alloWable level is 80% and thus, the ratio
roller 42K electrostatically. Further, the lamellation blade
is thus added, the toner amount in the developing apparatus
Will exceed the capacity of the developing apparatus. For
example, in a case Where the ratio of neW toner after the
pre-toner- supply operation is 20% and the neW toner amount
supplied in the pre-toner-supply operation (step S4 of FIG. 8)
is 10 g, the old toner amount in the developing apparatus is
of neW toner after neW toner is supplied is made to be 80%,
160 g of neW toner in the developing apparatus is required
(i.e., 160 [g]/(40 [g]+l60 [g]):0.8). Since 10 g ofneW toner
moves to the developing roller 41K from the toner supply
65
45K may be made to be apart from the developing roller 41K.
Thereby, the toner layer on the developing roller 41K
becomes thicker, and thus, it is possible to move the toner
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