US007668470B2

(12) United States Patent (io) Patent No.: US 7,668,470 B2

Tsuji et al. (45) Date of Patent: Feb. 23, 2010

(54) TONER SUPPLYING METHOD, TONER 6,795,660 B2* 9/2004 Yugetaetal 399/27
SUPPLYING DEVICE, DEVELOPING 7,110,707 B2* 9/2006 Nishitani 399/258
DEVICE, AND IMAGE FORMING 7,269,364 B2 * 9/2007 Tanakaetal 399/27
APPARATUS WITH CONTROLLED TONER 7,421,216 B2* 9/2008 Ondaetal 399/27
SUPPLY 2003/0210929 Al 11/2003 Otaetal.

(75) Inventors: Akiko Tsuji, Kameyama (JP); Shuhichi

FOREIGN PATENT DOCUMENTS
Morikuni, Nara (JP); Takahiko
Kimura, Ikoma (JP) JP 62-050778 3/1987
JP 63-168458 11/1988
(73) Assignee: Sharp Kabushiki Kaisha, Osaka (JP) JP 11-295975 10/1999
JP 2001-255727 9/2001
(*) Notice: Subject to any disclaimer, the term of this JP 2004-347794 A 12/2004
patent is extended or adjusted under 35 JP 2006-47777 A 2/2006
U.S.C. 154(b) by 519 days.

(21) Appl.No.: 11/700,891 * cited by examiner

(22) Filed: Feb. 1, 2007 Primary Examiner—William J Royer

(74) Attorney, Agent, or Firm—Nixon & Vanderhye, PC.
(65) Prior Publication Data
(57) ABSTRACT
US 2007/0217798 Al Sep. 20, 2007

(30) Foreign Application Priority Data A toner supplying device includes: a toner density sensor for
detecting a density of toner contained in a developer tank; a
Mar. 20,2006 (JP) 2006-077795 toner hopper for supplying toner to the developer tank; a toner
cartridge for supplying toner to the toner hopper; and a con-
(51) Int. CI.
trol section, when a request to supply toner to the developer
G03G15/08 (2006.01)
tank is made in accordance with a signal detected by the toner
(52) U.S. CI 399/27; 399/258 density sensor, for controlling a hopper driving motor and a
(58) Field of Classification Search 399/27, cartridge driving motor so that (i) the toner hopper supplies
399/258 toner to the developer tank and (ii) the toner cartridge supplies
See application file for complete search history. toner to the toner hopper. Thus, in a structure having first and
(56) References Cited second toner supplying sections disposed on top of each
other, toner can be stably supplied to a developer tank.
U.S. PATENT DOCUMENTS
5,652,947 A * 7/1997 Izumizaki 399/258 17 Claims, 26 Drawing Sheets

CARTRIDGE
100~- TONER CARTRIDGE DRIVING •150
101 MOTOR
VI

•4>
REMAINING TONER HOPPER
110- TONER HOPPER 116 — AMOUNT SENSOR DRIVING -151
MOTOR

SUPPLYING -80
PIPE

140— DEVELOPER TANK

TONER DENSITY SENSOR

160
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U.S. Patent Feb. 23, 2010 Sheet 21 of 26 US 7,668,470 B2

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U.S. Patent Feb. 23,2010 Sheet 22 of 26 US 7,668,470 B2

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U.S. Patent Feb. 23,2010 Sheet 23 of 26 US 7,668,470 B2

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U.S. Patent Feb.23, 2010 Sheet 25 of 26 US 7,668,470 B2

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U.S. Patent Feb. 23,2010 Sheet 26 of 26 US 7,668,470 B2

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 US 7,668,470 B2
1
TONER SUPPLYING METHOD, TONER Further, in Patent Document 2 (Japanese Unexamined
SUPPLYING DEVICE, DEVELOPING Patent Publication No. 50778/1987 (Tokukaisho 62-50778;
DEVICE, AND IMAGE FORMING published on March 5)), a toner density sensor is provided in
APPARATUS WITH CONTROLLED TONER a developer tank, and a toner supplying roller is provided in a
SUPPLY 5 toner-supplying opening of a toner tank (toner hopper).
Moreover, the rotation of the toner supplying roller is con-
This Nonprovisional application claims priority under 35 trolled in accordance with a result of detection carried out by
U.S.C. § 119(a)onPatentApplicationNo.077795/2006filed the toner density sensor.
in Japan on Mar. 20, 2006, the entire contents of which are
Meanwhile, in recent years, a toner supplying device
hereby incorporated by reference. 10
including a toner cartridge has been commonly used for the
FIELD OF THE INVENTION purpose of increasing the level of convenience in supplying
toner to a developer tank. According to such a developing
The technology disclosed herein relates to a toner supply- device, as described in Patent Document 3 (Japanese Unex-
ing method, a toner supplying device, a developing device, amined Patent Publication No. 255727/2001 (Tokukai 2001-
and an image forming apparatus by which or in which toner 255727; published on Sep. 21,2001)) and Patent Document 4
serving as a developer is supplied to a developer tank.
(Japanese Unexamined Patent Publication No. 295975/1999
BACKGROUND OF THE INVENTION (Tokukaihei 11-295975; published on Oct. 29, 1999)), the
toner cartridge supplies toner to a toner hopper, and the toner
Conventionally, electrophotographic image forming appa- 20 hopper supplies toner to the developer tank. In this case, the
ratuses such as copiers, printers, and facsimile machines have toner hopper functions as an adjuster by which toner supplied
been known. The electrophotographic method makes it pos- from the toner cartridge is smoothly supplied to the developer
sible to easily form a high-quality image, and therefore has tank by appropriate amounts. Further, for the purpose of
been widely adopted by the various image forming appara- miniaturization of a developing device, a typical toner hopper
tuses. 25 is small, and can contain only a small amount of toner. On the
Generally, an image forming apparatus adopting the elec-
other hand, for the purpose of reducing exchange frequency,
trophotographic method carries out the following operations. a typical toner cartridge is larger than a typical toner hopper,
Specifically, a surface of a photoreceptor containing a photo-
and contains a larger amount of toner than does a typical toner
conductive substance is uniformly charged. The photorecep-
hopper.
tor's surface thus charged is irradiated with light that is based 30
According to such a developing device, as described in
on image information, so that an electrostatic latent image is
Patent Document 3, a developer container (developer tank) is
formed. The electrostatic latent image thus formed is visual-
ized by supplying toner to the electrostatic latent image, so provided with a toner density sensor, and a toner hopper is
provided with a remaining toner amount sensor. Moreover,
that a toner image is obtained. The toner image thus obtained
is transferred from the photoreceptor onto a recording 35 when a shortage in toner in the toner hopper is detected by the
remaining toner amount sensor, the toner cartridge supplies
medium. The toner image thus transferred onto the recording
toner to the toner hopper. When a shortage in toner in the
medium is fixed to the recording medium by heat, pressure,
developer tank is detected by the toner density sensor, the
and the like.
toner hopper supplies toner to the developer container.
Toner to be used for developing the electrostatic latent
image is supplied from a developing device to the surface of 40 See a case where a two-step toner supplying device, in
the photoreceptor. The developing device includes a devel- which, as described above, a toner cartridge (first toner sup-
oper tank. The developer tank contains toner, and has a devel- plying means) supplies toner to a toner hopper (second toner
oping roller, a doctor blade, and a stirring roller. The devel- supplying means) and the toner hopper supplies toner to a
oping roller is provided so as to make contact with the surface developer tank, is arranged such that, as described above, the
of the photoreceptor, has a surface on which a toner layer is 45 toner cartridge supplies toner to the toner hopper in accor-
carried, and supplies toner to the electrostatic latent image. dance with a result of detection carried out by the remaining
The doctor blade includes a plate member provided so as to toner amount sensor of the toner hopper. In this case, toner
make contact with the surface of the developing roller, and may not be smoothly supplied to the developer tank. That is,
regulates the thickness of the toner layer carried on the sur- slow detection of a correct remaining amount of toner or false
face of the developing roller. The stirring roller carries out a 50 detection of a remaining amount of toner may be caused
rotation operation, so that (i) the toner is charged and (ii) the depending on (i) a location at which the remaining toner
toner thus charged is supplied to an area surrounding the amount sensor is disposed in the toner hopper, (ii) a direction
developing roller. in which toner is flowed, and (iii) the like. Alternatively, in
The developing device further includes a toner hopper cases where a large amount of toner is consumed for the
serving as a toner supplying device. The toner hopper is 55 purpose of printing a document having a high coverage rate or
designed to supply toner to the developer tank. continuously carrying out a large amount of printing, the
For example, in Patent Document 1 (Japanese Unexamined toner cartridge may supply toner to the toner hopper belat-
Utility Model Publication No. 168458/1988 (Jitsukaisho edly. In such a case, the density of toner contained in the
63-168458; published on Nov. 2, 1988)), a plurality of toner developer tank becomes insufficient, and this causes a devel-
amount sensors are provided on a side wall of a supplying 60 oping device to have a problem in carrying out a development
tank (toner hopper) so as to be on top of one another, and a operation. Such a problem becomes significant especially in
supplying roller is provided in a toner-supplying opening via an arrangement in which the toner hopper is miniaturized for
which toner is supplied from the supplying tank. Moreover, the purpose of miniaturizing the device.
the rotation speed of the supplying roller is controlled in Therefore, it is an object of the technology described herein
accordance with the amount of toner remaining in the sup- 65 to provide a toner supplying method, a toner supplying
plying tank which amount is detected by the plurality of toner device, a developing device, and an image forming apparatus
amount sensors. each of which makes it possible to stably supply toner to a
 US 7,668,470 B2

developer tank in an arrangement in which first and second FIG. 7 is a cross-sectional view taken along the arrow J-J of
toner supplying means disposed on top of each other are FIG. 4.
provided. FIG. 8 is a perspective view of a toner transporting screw of
the toner hopper shown in FIG. 4.
SUMMARY OF THE INVENTION 5 FIG. 9(a) is a perspective view of a pipe portion of a
supplying pipe shown in FIG. 1.
A toner supplying device of the technology described FIG. 9 (b) is a longitudinal sectional view of the pipe
herein includes: a toner density sensor for detecting a toner portion shown in FIG. 9(a).
density in a developer tank; a first toner supplying section for FIG. 10 is a block diagram showing an arrangement of a
supplying toner to the developer tank; a second toner supply- 10 control device of the toner supplying device shown in FIG. 1.
ing section for supplying toner to the first toner supplying FIG. 11 is a graph showing a relationship between (i) the
section; and control section, when a request to supply toner to toner cartridge driving time during which a toner cartridge
the developer tank is made in accordance with a signal shown in FIG. 3 is driven, and (ii) the amount of toner remain-
detected by the toner density sensor, for controlling the first ing in the toner cartridge.
toner supplying section and the second toner supplying sec- 15 FIG. 12 is a timing chart showing an example of control
tion so that (i) the first toner supplying section supplies toner operation carried out with respect the toner supplying device
to the developer tank and (ii) the second toner supplying by the control device shown in FIG. 10.
section supplies toner to the first toner supplying section. FIG. 13 is a timing chart showing a control operation
Further, a toner supplying method of the technology carried out by the control device in cases where a remaining
described herein is a method for supplying toner from a first 20 toner amount sensor always indicates "Low", in the example
toner supplying section to a developer tank, and for supplying shown in FIG. 12.
toner from a second toner supplying section to the first toner FIG. 14 is a timing chart showing a control operation
supplying section, the method, including the step of: when a carried out by the control device in cases where the remaining
shortage in toner density in the developer tank is detected, (i) toner amount sensor always indicates "High", in the example
causing the first toner supplying section to supply toner to the 25 shown in FIG. 12.
developer tank and (ii) causing the second toner supplying
FIG. 15 is a timing chart showing another example of
section to supply toner to the first toner supplying section. control operation carried out with respect to the toner supply-
According to the foregoing arrangement, in cases where a
ing device by the control device shown in FIG. 10.
shortage in toner density in the developer tank is detected, the
FIG. 16 is a timing chart showing another example of
first toner supplying section supplies toner to the developer 30
control operation carried out with respect to the toner supply-
tank and the second toner supplying section supplies toner to
ing device by the control device shown in FIG. 10.
the first toner supplying section. Therefore, the supply of
FIG. 17(a) is a side view of the toner cartridge shown in
toner from the second toner supplying section to the first toner
FIG. 3.
supplying section is not carried out depending on a result of
FIG. 17(b) is a perspective view of the toner cartridge
detection carried out by a remaining toner amount sensor 35
shown in FIG. 3.
provided for example in the first toner supplying section, but
is carried out in cases where a shortage in toner density in the FIG. 18 is a side view of a top end portion of a toner bottle,
shown in FIG. 17(a), which is provided in the toner cartridge.
developer tank is detected, i.e., in cases where the first toner
supplying section supplies toner to the developer tank. FIG. 19 is a side view illustrating that a scraper is mounted
Thus, even when the first toner supplying section has a 40 in the toner bottle's top end portion shown in FIG. 18.
small size and a small capacity, belated supply of toner from FIG. 20 is a front view of the toner bottle shown in FIG. 19.
the second toner supplying section to the first toner supplying FIG. 21 is a perspective view of a lower surface of a bottle
section is prevented, so that there is no shortage in remaining supporting member shown in FIGS. 17(a) and 17(b).
toner amount in the first toner supplying section. This makes FIG. 22(a) is a perspective view of a first housing consti-
it possible to stably supply toner from the first toner supplying 45 tuting the bottle supporting member shown in FIG. 21.
section to the developer tank. FIG. 22(b) is a perspective view of a second housing con-
Additional objects, features, and strengths of the technol- stituting the bottle supporting member shown in FIG. 21.
ogy described herein will be made clear by the description FIG. 23 is an explanatory diagram showing a relationship
below. Further, the advantages of the technology described between (i) a toner discharging chamber of the toner support-
herein will be evident from the following explanation in ref- 50 ing member shown in FIG. 21 and (ii) a location where the
erence to the drawings. scraper of the toner bottle is provided.
FIG. 24 is a schematic longitudinal sectional view of the
BRIEF DESCRIPTION OF THE DRAWINGS toner bottle's top end portion shown in FIG. 19.
FIG. 25 is a schematic longitudinal sectional view illus-
FIG. 1 is a pattern diagram showing a developing device 55 trating that the bottle supporting member is attached to the
including a toner supplying device according to an example toner bottle's top end portion shown in FIG. 19.
embodiment. FIG. 26(a) is an explanatory diagram showing a state in
FIG. 2 is a front view showing an inner structure of a printer which a shutter member is open in the toner cartridge shown
including the developing device shown in FIG. 1. in FIGS. 17(a) and 17(b).
FIG. 3 is a perspective view of the developing device go FIG. 26(b) is an explanatory diagram showing a state in
shown in FIG. 1. which the shutter member is closed in the toner cartridge
FIG. 4 is a perspective view of a toner hopper shown in shown in FIGS. 17(a) and 17(b).
FIG. 1.
FIG. 5 is a cross-sectional view taken along the arrow H-H DESCRIPTION OF THE EMBODIMENTS
of FIG. 4. 65
FIG. 6 is a cross-sectional view taken along the arrow I-I of An embodiment of the technology described herein will be
FIG. 4. described below. In the present embodiment, an example is
 US 7,668,470 B2

explained in which a toner supplying device of the technology The intermediate transfer rollers 6 are rotatably supported
described herein is applied to a printer, which is a type of in intermediate transfer roller installation parts of the inter-
image forming apparatus. mediate transfer belt tension mechanism 73 of the interme-
FIG. 2 is a diagram schematically showing an arrangement diate transfer belt unit 8, respectively. The intermediate trans-
of a printer according to the present embodiment. The printer 5 fer rollers 6 give transfer bias for transferring respective toner
A forms, in accordance with image data transmitted from images of the photoreceptor drums 3 onto the intermediate
outside, a monochrome or multicolor image on a predeter- transfer belt 7.
mined sheet (recording paper sheet). As shown in FIG. 2, the The intermediate transfer belt 7 is provided so as to make
printer A includes an exposure unit 1, developing devices 2 contact with each of the photoreceptor drums 3. The toner
(2a, 2b, 2c, 2d), photoreceptor drums 3 (3a, 5b, 3c, id), 10 images which respectively have the four colors and which are
chargers 5 (5a, 5b, 5c, 5<f), cleaner units 4 (4a, 4b, 4c, 4<f), an formed respectively on the photoreceptor drums 3 are trans-
intermediate transfer belt unit 8, a fixing device 12, a paper ferred onto the intermediate transfer belt 7 so as to be sequen-
sheet transportation path S, a paper sheet feeding tray 10, a tially superimposed on one another. With this, a color toner
paper sheet discharging tray 15, and the like. image (multicolor toner image) is formed on the intermediate
The image data to be processed in the printer A corresponds 15 transfer belt 7. The intermediate transfer belt 7 is made of a
to a color image made up of four colors: black (K), cyan (C), film having a thickness of approximately 100 (im to 150 jxm,
magenta (M), and yellow (Y). Accordingly, the printer A is and has no ends.
provided with four image stations. The four image stations The transfer of the toner images from the photoreceptor
form four types of latent image corresponding to the four drums 3 onto the intermediate transfer belt 7 is carried out by
colors, respectively. An image station corresponding to black 20 the intermediate transfer rollers 6 making contact with a back
(K) includes the developing device 2a, the photoreceptor side of the intermediate transfer belt 7. To each of the inter-
drum 3a, the charger 5a, and the cleaner unit 4a. An image mediate transfer rollers 6, a high-voltage transfer bias (high
station corresponding to cyan (C) includes the developing voltage whose polarity (+) is reverse to the charging polarity
device 2b, the photoreceptor drum 3b, the charger 5b, and the (-) of the toner) is applied for the purpose of transferring the
cleaner unit 4b. The image station corresponding to magenta 25 toner images.
(M) includes the developing device 2c, the photoreceptor
The intermediate transfer roller 6 has, as its base, a metal
drum 3c, the charger 5c, and the cleaner unit 4c. The image (e.g., stainless-steel) shaft having a diameter of 8 mm to 10
station corresponding to yellow (Y) includes the developing
mm. The intermediate transfer roller 6 has a surface covered
device 2d, the photoreceptor drum id, the charger 5d, and the
with an electrically-conductive elastic material (e.g., EPDM
cleaner unit 4d. 30
and urethane foam). Such an electrically-conductive elastic
The photoreceptor drums 3 are provided (installed) in an
material enables the intermediate transfer roller 6 to apply the
upper portion of the printer A so as to form an electrostatic high voltage uniformly to the intermediate transfer belt 7. The
latent image in accordance with the image data.
intermediate transfer roller 6 employs a roller-type transfer
The chargers 5 serve as charging means for uniformly electrode in the present embodiment, but may employ a
charging surfaces of the photoreceptor drums 3 at predeter- 35
brush-type transfer electrode instead.
mined potentials, respectively. See FIG. 2. Each of the charg-
The electrostatic latent images which are formed respec-
ers 5 may be, e.g., a contact-roller-type charger, a brush-type
tively on the photoreceptor drums 3 and which are visualized
charger, and a discharge-type charger.
respectively in accordance with the colors are superimposed
As shown in FIG. 2, the exposure unit 1 may be a laser
on the intermediate transfer belt 7 so as to become the image
scanning unit (LSU) including a laser irradiation section and 40
information sent to the apparatus. The image information thus
a reflective mirror. Alternatively, the exposure unit 1 may be
obtained by the superimposition is sent, by the rotation of the
an EL or LED writing head including light-emitting elements
intermediate transfer belt 7, to a position where a below-
arranged in an array manner.
mentioned paper sheet comes into contact with the interme-
The exposure unit 1 has a function of exposing the electri-
diate transfer belt 7. Then, the image information is trans-
fied photoreceptor drums 3 in accordance with the input 45
ferred onto the paper sheet by a transfer roller 11 provided in
image data. With this, electrostatic latent images are respec-
the position.
tively formed on the surfaces of the photoreceptor drums 3 in
accordance with the image data. In this case, the intermediate transfer belt 7 and the transfer
The developing devices 2 visualize, with toner (black (K), roller 11 are pressed against each other so that a predeter-
cyan (C), magenta (M), yellow (Y)), the electrostatic latent 50 mined nip is formed between the intermediate transfer belt 7
images formed on the photoreceptor drums 3, respectively. and the transfer roller 11. To the transfer roller 11, a voltage
After the image is developed and transferred, some toner (high voltage whose polarity (+) is reverse to the charging
remaining on the respective surfaces of the photoreceptor polarity (-) of the toner) for transferring the toner to the
drums 3 is removed and collected by the cleaner units 4. recording paper sheet is applied.
The intermediate transfer belt unit 8 provided above the 55 Furthermore, while either one of the transfer roller 11 and
photoreceptor drums 3 includes an intermediate transfer belt the intermediate transfer belt driving roller 71 is made of a
7, an intermediate transfer belt driving roller 71, an interme- hard material (e.g., metal), the other is made of a soft material
diate transfer belt tension mechanism 73, an intermediate (e.g., elastic rubber or resin foam). With this, the nip can be
transfer belt driven roller 72, intermediate transfer rollers 6 constantly obtained.
(6a, 6b, 6c, 6<f), and an intermediate transfer belt cleaning unit 60 Further, as described above, the toner adheres to the inter-
9. mediate transfer belt 7 as the result of the contact of the
The intermediate transfer belt 7 is stretched and provided intermediate transfer belt 7 with the photoreceptor drums 3,
on and across the intermediate transfer belt driving roller 71, or the toner is not transferred onto the sheet by the transfer
the intermediate transfer belt tension mechanism 73, the roller 11 and accordingly remains on the intermediate transfer
intermediate transfer rollers 6, the intermediate transfer belt 65 belt 7. Such toner causes a mixture of the colors of toner in the
driven roller 72, and the like, and is also driven to rotate in the next step. Therefore, the toner is removed and collected by the
direction indicated by an arrow B. intermediate transfer belt cleaning unit 9.
 US 7,668,470 B2
8
The intermediate transfer belt cleaning unit 9 includes, pickup roller 16-2 is provided in the manual paper sheet
e.g., a cleaning member which makes contact with the inter- feeding tray 20 so as to feed the sheets one by one to the paper
mediate transfer belt 7. Examples of the cleaning member sheet transportation path S.
include a cleaning blade. The intermediate transfer belt 7 Each of the sheets transported from the paper sheet feeding
5 tray 10 is transported to the resist roller 14 by a transportation
making contact with the cleaning blade is supported by the
intermediate transfer belt driven roller 72 so that the back side roller 25-1 provided in the paper sheet transportation path S.
of the intermediate transfer belt 7 makes contact with the At such a timing that the head of the sheet is aligned with the
intermediate transfer belt driven roller 72. head of the image information on the intermediate transfer
The paper sheet feeding tray 10 serves as a tray for storing belt 7, the sheet is transported to the transfer roller 11 so that
sheets (recording paper sheets) used for image formation. The the image information is written on (transferred onto) the
paper sheet feeding tray 10 is provided below the image sheet. Thereafter, the sheet is brought to the fixing device 12
forming section and the exposure unit 1 of the printer A. so that the toner yet to be fixed on the sheet is melted and fixed
by heat on the sheet. The sheet is discharged by the transpor-
Further, the paper sheet discharging tray 15 serves as a tray tation roller 25-3, serving also as a paper sheet discharging
for loading printed sheets in a face-down manner, i.e., in such roller, to the paper sheet discharging tray 15 via the transpor-
a manner that printed sides of the sheets face down. The paper tation roller 25-2. Note that this is a case of single-side print-
sheet discharging tray 15 is provided in an upper portion of ing.
the printer A. On the other hand, each of the sheets loaded on the manual
Further, the printer A is provided with the paper sheet paper sheet feeding tray 20 is fed by the pickup roller 16-2,
transportation path S for sending the sheets from the paper 20 and then reaches the resist roller 14 via a plurality of trans-
sheet feeding tray 10 to the paper sheet discharging tray 15 via portation rollers (25-6, 25-5, 25-4). Thereafter, the sheet is
the transfer roller 11 and the fixing device 12. The paper sheet discharged to the paper sheet discharging tray 15 after being
transportation path S extends substantially vertically. Fur- subjected to the same process as the sheet fed from the paper
thermore, provided near the paper sheet transportation path S sheet feeding tray 10. Note that this is the case of single-side
extending from the paper sheet feeding tray 10 to the paper 25 printing.
sheet discharging tray 15 are a pickup roller 16-1, a resist On the other hand, see a case where double-side printing is
roller 14, the transfer roller 11, the fixing device 12, and required on this occasion. After the sheet subjected to the
transportation rollers 25 (25-1, 25-2, 25-3) for transporting single-side printing passes through the fixing device 12, the
the sheets. back end of the sheet is clamped by the transportation roller
Each of the transportation rollers 25 is a small roller for 30 25-3. The transportation roller 25-3 rotates in a reverse direc-
facilitating/assisting the transportation of the sheets. The tion so as to guide the sheet to transportation rollers (25-7,
transportation rollers 25 are provided along the paper sheet 25-8). Thereafter, the sheet is subjected to back-side printing
transportation path S. after passing through the resist roller 14, and then is dis-
The pickup roller 16-1 is a feeding roller provided on one charged to the paper sheet discharging tray 15.
end of the paper sheet feeding tray 10 so as to supply the 35 The developing devices 2 (2a, 2b, 2c 2d) include developer
sheets one by one to the paper sheet transportation path S. tanks 140 (140a, 1406,140c, 140<f), respectively. Further, in
The resist roller 14 temporarily suspends the transportation order to be able to process a large amount of printing at a high
of each of the sheets via the paper sheet transportation path S. speed, the developing devices 2 {2a, 2b, 2c, 2d) includes toner
At such a timing that the head of the sheet is aligned with the supplying devices 101 (101a, 101a, 1016, 101c, lOlrf) for
head of each of the toner images on the photoreceptor drums 40 supplying toner to the developer tanks 140 (140a, 1406,140c,
3, the resist roller 14 transports the sheet to a transfer section. 140<f), respectively. The toner supplying devices (101a, 101a,
1016,101c, lOlrf) include toner cartridges 100 (100a, 100a,
The fixing device 12 includes a heat roller 31 and a pressure 1006, 100c, 100<f), toner hoppers 110 (110a, 110a, 1106,
roller 32. The heat roller 31 and the pressure roller 32 rotate 110c, HOrf), and supplying pipes 80 (80a, 806, 80c, 80rf),
with the sheet sandwiched therebetween. The heat roller 31 is 45 respectively.
controlled by a control section in accordance with a signal Each of the toner cartridges 100a contains black (K) toner
from a temperature detector (not shown) so as to be set at a as supplementary toner. Similarly, the toner cartridges 1006,
predetermined fixing temperature. The sheet between the heat 100c, and 100<i contain cyan (C) toner, magenta (M) toner,
roller 31 and the pressure roller 32 is subjected to heat and and yellow (Y) toner, respectively.
pressure. This causes melting and mixing of the multicolor As shown in FIG. 3, a toner supplying device 101 is pro-
toner image, transferred onto the sheet, with the result that the vided directly above a developer tank 140. The toner supply-
multicolor toner image is pressed and fixed by heat on the ing device 101 is arranged such that a toner cartridge 100 is
sheet. provided on top of a toner hopper 110. The toner hopper 110
The paper sheet having the multicolor toner image fixed is connected to the developer tank 140 by a supplying pipe 80
thereon is transported by the transportation rollers 25 to a 55 extending from top to bottom. Supply of toner from the toner
reverse paper sheet discharging path of the paper sheet trans- cartridge 100 to the toner hopper 110 and supply of toner from
portation path S, and then is discharged onto the paper sheet the toner hopper 110 to the developer tank 140 via the sup-
discharging tray 15 in a reversed manner (i.e., in such a plying pipe 80 are carried out on an end portion side on which
manner that the multicolor toner image faces down). the supplying pipe 80 is provided. The toner cartridge 100 is
The following explains in detail the sheet transportation 60 driven by a cartridge driving motor 150, and the toner hopper
path S. The printer A is provided with not only the paper sheet 110 is driven by a hopper driving motor 151.
feeding tray 10 for preliminarily storing the sheets, but also a Further, the intermediate transfer belt unit 8 is provided
manual paper sheet feeding tray 20 allowing a user to print a between the toner cartridge 100 and the toner hopper 110. The
small number of sheets without opening and closing the paper supplying pipe 80a for supplying black (K) toner is structured
sheet feeding tray 10. The pickup roller 16-1 is provided in the 65 such that: developers respectively contained in the two toner
paper sheet feeding tray 10 so as to feed the sheets one by one cartridges 100a are combined, and then are supplied to the
to the paper sheet transportation path S. On the other hand, a toner hopper 110a, i.e., to the developer tank 140a.
 US 7,668,470 B2
10
The toner hopper 110 of the toner supplying devices 101 The following explains a toner supply control operation of
has a structure shown in FIGS. 4 through 7. FIG. 4 is a the toner supplying device 101 supplying toner to the devel-
perspective view of the toner hopper 110. FIG. 5 is a cross- oper tank 140. The toner supplying device 101 has a control
sectional view taken along an arrow H-H of FIG. 4. FIG. 6 is device 170 shown in FIG. 10. The control device 170 controls,
a cross-sectional view taken along an arrow I-I of FIG. 4. FIG. 5 in accordance with signals detected by the toner density sen-
7 is a cross-sectional view taken along an arrow J-J of FIG. 4. sor 160 and by the remaining toner amount sensor 116, how
As shown in FIG. 4, the toner hopper 110 includes two toner the cartridge driving motor 150 and the hopper driving motor
transportation paths, namely a first toner transportation path 151 are operated.
111 and a second toner transportation path 112. The first and That is, the control device 170 carries out a first control
second toner transportation paths 111 and 112 are divided by 10 operation as follows: In cases where it is determined, in
a divider plate 113. Each of the first and second toner trans- accordance with a result of detection carried out by the
portation paths 111 and 112 has an elongate shape. The first remaining toner amount sensor 116, that the amount of toner
and second toner transportation paths 111 and 112 are con- remaining in the toner hopper 110 is insufficient, the cartridge
nected to each other at an end edge portion of a direction driving motor 150 is rotated, so that the toner cartridge 100
(direction C) in which toner is transported via the first toner 15 supplies toner to the toner hopper 110. Further, the control
transportation path 111. device 170 carries out a second control operation as follows:
Provided above a beginning edge portion of the first toner In cases where it is determined, in accordance with a result of
transportation path 111 is a toner inlet 114 via which toner detection carried out by the toner density sensor 160, that the
supplied from the toner cartridge 100 is introduced into the density of toner contained in the developer tank 140 is insuf-
toner hopper 110. Further, as shown in FIG. 7, provided in a 20 ficient, the hopper driving motor 151 is rotated, so that the
bottom wall portion below an end edge portion of a direction toner hopper 110 supplies toner to the developer tank 140.
(direction D) in which toner is transported via the second Further, during the second control operation, the control
toner transportation path 112 is a toner outlet 115 via which device 170 rotates the cartridge driving motor 150 in cases
toner is inputted to the supplying pipe 80. where the control device 170 has rotated the hopper driving
Further, provided in a side wall portion near the toner inlet 25 motor 151. Specifically, in cases where the hopper driving
114 of the first toner transportation path 111 is a remaining motor 151 has been rotated for a first set time (predetermined
toner amount sensor 116 for detecting the presence of toner in time) or longer, the cartridge driving motor 150 is rotated for
that region. a second set time (predetermined time).
Each of the first and second toner transportation paths 111 Thus, during the second control operation, the cartridge
and 112 is provided with a toner transporting screw 118 30 driving motor 150 is rotated in conjunction with the rotation
shown in FIG. 8. Therefore, toner supplied to the toner hopper of the hopper driving motor 151 regardless of a result of
110 via the toner inlet 114 is transported in the direction C via detection carried out by the remaining toner amount sensor
the first toner transportation path 111 by the toner transport- 116, so that the toner hopper 110 is always kept substantially
ing screw 118, and is transferred to the second toner trans- full of toner. Thus, even in cases where the toner hopper 110
portation path 112 via the end edge portion of the first toner 35 is small and can contain only a small amount of toner, the
transportation path 111. The toner is transported in the direc- developer tank 140 can be supplied with toner stably, i.e.,
tion D via the second toner transportation path 112 by the uninterruptedly and continuously.
toner transporting screw 118, and then is dropped into the Particularly, in the present embodiment, the toner hopper
supplying pipe 80 via the toner outlet 115. 110 has a small capacity, and is arranged so as to supply toner
Thus, in the toner supplying device 101, the toner supplied 40 to the developer tank 140 while transporting toner in the
from the toner cartridge 100 to the toner hopper 110 is trans- horizontal directions via the first and second toner transpor-
ported in the horizontal directions via the first toner transpor- tation paths 111 and 112. In this case, the toner supplied to the
tation path 111 and the second toner transportation path 112, first toner transportation path 111 via the toner inlet 114 is
and then is supplied to the developer tank 140 via the supply- sequentially transported from the location of the toner inlet
ing pipe 80. 45 114 to the toner outlet 115 via the first and second toner
In the present embodiment, the toner hopper 110 can con- transportation paths 111 and 112 by the toner transporting
tain only a small amount of toner, e.g., 30 g of toner. With this screw 118. Therefore, when the supply of toner from the toner
amount of toner, a 6% solid image can be printed on approxi- cartridge 100 to the toner hopper 110 is interrupted while the
mately 1000 A4 paper sheets. toner hopper 110 is transporting toner, the first and second
Specifically, the supplying pipe 80 has a circular pipe por- 50 toner transportation paths 111 and 112 are likely to have a
tion 81 shown in FIGS. 9(a) and 9{b). FIG. 9(a) is a perspec- region free of toner. When such a situation arises, the supply
tive view of the pipe portion 81, and FIG. 9{b) is a longitudi- of toner from the toner hopper 110 to the developer tank 140
nal sectional view of the pipe portion 81. is temporarily interrupted, so that the supply of toner to the
The toner cartridge 100 shown in FIG. 3 is a rotary toner developer tank 140 becomes unstable. As a result, the density
bottle type, and therefore supplies toner to the supplying pipe 55 of toner contained in the developer tank 140 becomes
80 while being rotated. The toner cartridge 100 of this type unstable.
makes it possible to easily and accurately control the amount In order to prevent such a situation, it is preferable that each
of toner to be supplied, and therefore is suitable to a structure of the first and second toner transportation paths 111 and 112
using the toner hopper 110 which has a small capacity and in of the toner hopper 110 be prevented from having a region
which toner is transported via the narrow transportation paths 60 free of toner, i.e., that the substantially whole area of each of
(first and second toner transportation paths 111 and 112). The the first and second toner transportation paths 111 and 112 be
toner cartridge 100 will be fully described later. filled with a predetermined amount of toner or more. In light
FIG. 1 is a pattern diagram showing a developing device 2 of this, in cases where the rotation of the hopper driving motor
including the toner supplying device 101. A toner density 151 causes toner to be transported via the first and second
sensor 160 shown in FIG. 1 is provided in the developer tank 65 toner transportation paths 111 and 112, it is preferable that:
140 so as to detect the density of toner contained in the the cartridge driving motor 150 be rotated regardless of a
developer tank 140. result of detection carried out by the remaining toner amount
 US 7,668,470 B2
11 12
sensor 116, so that toner is supplied from the toner cartridge (2) When integrated time during which the hopper driving
100 so as to prevent a region free of toner (such a region being motor 151 is rotated has reached three seconds, an opera-
hereinafter referred to as "toner shortage region") from being tion of supplying toner from the toner cartridge 100 is
generated in a part, which is directly below the toner inlet 114, carried out for five seconds.
5
of the first toner transportation path 111. Therefore, in this FIG. 12 shows an example (Case 1-1) in which the aforemen-
case, the cartridge driving motor 150 is rotated in conjunction tioned control operations (1) and (2) are carried out.
with the rotation of the hopper driving motor 151. However, In FIG. 12, the operation (al) of the toner cartridge 100 is
the cartridge driving motor 150 does not need to start to be attributed to the control operation (1) or (2). The operation
rotated at the same time as the hopper driving motor 151 starts period during which the toner cartridge 100 is operated due to
to be rotated. The cartridge driving motor 150 may start to be the control operation (1) corresponds to the operation period
rotated later than a point of time at which the hopper driving during which the toner cartridge 100 is operated due to the
motor 151 starts to be rotated, as long as the toner cartridge control operation (2). Therefore, the toner cartridge 100 is not
100 can supply toner to the toner hopper 110 so that a toner operated in accordance with each of the control operations (1)
shortage region is not generated. ., and (2).
Substantially a certain amount of toner is gradually dis- The operation (a2) of the toner cartridge 100 is started due
charged from the toner hopper 110 to the supplying pipe 80 in to the control operation (2). In this example, the integrated
accordance with the rotation of the toner transporting screw time during which the toner hopper 110 is rotated has reached
118. Therefore, even when the supplying pipe 80 has a narrow three seconds before the five-second-long operation (a2) of
the toner cartridge 100 is finished, so that the next operation
toner passageway, no toner clog is generated within the toner 20
(a3) due to the control operation (2) is started. In this case, a
passageway.
calculation of an amount of time during which the toner
In order to carry out the foregoing control operation, the cartridge 100 is operated is started at the same time as the
control device 170 includes a cartridge driving motor control operation (a3) is started. The same holds for the operation
section 171, a hopper driving motor control section 172, and (a4). That is, the integrated time during which the toner hop-
a display device control section. 173. The display device per 110 is rotated has reached three seconds before the five-
control section 173 supplies display data to a display device second-long operation (a3) of the toner cartridge 100 is fin-
174 for displaying various states of the toner supplying device ished, so that the operation (a4) due to the control operation
101 and of the developing device 2, and causes the display (2) is started. After the toner cartridge 100 has carried out the
device 147 to display information concerning the various 30 five-second-long operation, the toner cartridge 100 finishes
states. The display device 147 is provided, for example, in an being operated.
operation panel of the printer A. FIG. 13 shows another example (Case 1-2) in which the
FIG. 11 shows a relationship between (i) the driving time aforementioned control operations (1) and (2) are carried out,
(continuous driving time) of the toner cartridge 100 of the and is a timing chart showing a toner supply control operation
present embodiment, and (ii) the amount of toner remaining 35 carried out in cases where the remaining toner amount sensor
in the toner cartridge 100. The driving time of the toner 116 always indicates a detection result "Low".
cartridge 100 corresponds to a period of time during which an In FIG. 13, the operation (bl) of the toner cartridge 100 is
after-mentioned toner bottle of the toner cartridge 100 is started due to the control operation (1). Thereafter, the inte-
rotated. As evidenced by FIG. 11, when the driving time grated time during which the toner hopper 110 is rotated has
exceeds 25 minutes, an unstable region appears where the 40 reached three seconds before the five-second-long operation
remaining amount of toner (amount of toner supplied) does (bl) of the toner cartridge 100 is finished, so that the next
not change linearly. operation (b2) due to the control operation (2) is started.
Furthermore, the next operation (b3) due to the control opera-
In the toner hopper 100 of the present embodiment, the
tion (1) is started before the five-second-long operation (b2)
remaining toner amount sensor 116 is provided near the toner
45 of the toner cartridge 100 is finished. After the operation (b3)
inlet 114. Therefore, also by carrying out, in accordance with is finished, the operation (b4) due to the control operation (2)
a result of detection carried out by the remaining toner
is started without interruption. Before the operation (b4) is
amount sensor 116, such a toner supply control operation that finished, the operation (b5) due to the control operation (1) is
the toner cartridge 100 supplies toner to the toner hopper 110,
started. Thereafter, the five-second-long operation (b5) of the
it is possible to prevent the toner hopper 110 from having a
50 toner cartridge 100 is finished. Then, a result of detection
toner shortage region.
carried out by the remaining toner amount sensor 116 is
The following explains examples of the toner supply con- judged. Since the detection result is judged to be "Low", the
trol operation so carried out by the control device 170 as to operation (b6) due to the control operation (1) is carried out
prevent the toner hopper 110 from having a toner shortage again.
region. FIG. 14 shows another example (Case 1-3) in which the
55
aforementioned control operations (1) and (2) are carried out,
EXAMPLE 1 and is a timing chart showing a toner supply control operation
carried out in cases where the remaining toner amount sensor
FIG. 12 is a timing chart showing an example of the toner 116 always indicates a detection result "High".
supply control operation carried out by the control device 6Q In FIG. 14, since the remaining toner amount sensor 116
170. In this example, the following two control operations are always indicates a detection result "High", the toner cartridge
carried out: 100 is not operated due to the control operation (1).
(1) One second after the remaining toner amount sensor 116 The operation (cl) of the toner cartridge 100 is started due
indicates a detection result "Low" (toner supply required), to the control operation (2), so that the toner cartridge 100
an operation of supplying toner from the toner cartridge 65 supplies toner for five seconds. Thereafter, when the inte-
100 is carried out for five seconds (the cartridge driving grated time during which the hopper driving motor 151 has
motor 150 is rotated for five seconds). reached three seconds, the operation (c2) of the toner car-
 US 7,668,470 B2
13 14
tridge 100 is carried out due to the control operation (2). tridge driving motor 150 may be rotated in accordance with a
Thereafter, the operation (c3) of the toner cartridge 100 is toner supply request that is based on a result of detection
similarly carried out due to the control operation (2). carried out by the toner density sensor 160. In this case, for
example, the cartridge driving motor 150 may be started at a
EXAMPLE 2 5 later timing than the hopper driving motor 151 is started. With
this, the toner cartridge 100 supplies toner to the toner hopper
FIG. 15 is a timing chart showing another example of the 110 so that the toner hopper 110 is prevented from having a
toner supply control operation carried out by the control toner shortage region.
device 170. In this example, the following control operation The following fully explains the toner cartridge 100. Note
(3) is carried out instead of the aforementioned control opera- 10 that the five toner cartridges 100 have the same structure.
tion (1). Note that the control operation (2) is carried out in the FIGS. 17(a) and 17(b) schematically show a structure of each
same manner as in Example 1. That is, the following two of the toner cartridges 100. FIG. 17(a) is a side view of the
operations are carried out: toner cartridge 100, and FIG. 17(b) is a front view of the toner
(3) At the point of time when (zero second after) the remain- cartridge 100 as seen from an end face side from which toner
ing toner amount sensor 116 indicates a detection result 15 is supplied.
"Low" (toner supply required), an operation of supplying As shown in FIG. 17(a), the toner cartridge 100 includes: a
toner from the toner cartridge 100 is carried out for five toner bottle 200, which contains toner serving as a developer;
seconds (the cartridge driving motor 150 is rotated for two and a bottle supporting member 300, which rotatably sup-
seconds). ports an end portion of the toner bottle 200.
(2) When integrated time during which the hopper driving 20 As shown in FIG. 17(b), the bottle supporting member 300
motor 151 is rotated has reached three seconds, an opera- has a bottom surface (surface that faces down when the toner
tion of supplying toner from the toner cartridge 100 is cartridge 100 is mounted in the printer A) on which a toner
carried out for five seconds. outlet is provided. Toner supplied from the toner bottle 200 is
FIG. 15 shows an example (Case 2-1) in which the aforemen- .. discharged to the toner hopper 110 via the toner outlet. Pro-
tioned control operations (3) and (2) are carried out. vided in the toner outlet is a shutter mechanism 400 for
In FIG. 15, the operation (dl) of the toner cartridge 100 is opening and closing the toner outlet.
started due to the control operation (3). In this example, the (Toner Bottle 200)
integrated time during which the toner hopper 110 is rotated As shown in FIG. 17(a), the toner bottle 200 includes a
has reached three seconds before the five-second-long opera- 30
main body portion 201 having a substantially cylindrical
tion (dl) of the toner cartridge 100 is finished, so that the next shape. The main body portion 201 has a top end portion 201a
operation (d2) due to the control operation (2) is started. supported by the bottle supporting member 300, and the top
The operation (d3) of the toner cartridge 100 is attributed to end portion 201a is provided with an opening via which toner
the control operation (2). However, the start of the operation is discharged. The main body portion 201 has a rear end
(d3) is attributed to the control operation (2) or (3). In this 35 portion 2016 opposite to the top end portion 201a, and the
example, the next operation (d4) due to the control operation rear end portion 2016 is closed.
(2) is started before the operation (d3) is finished. The opera- Further, the main body portion 201 has a surface on which
tion (d5) is started in the same manner as the operation (d4) is a plurality of groove portions 201c are provided, and the
started. Thereafter, after the toner cartridge 100 has carried groove portions 201c are depressed toward the rotation axis
out the five-second-long operation, the toner cartridge 100 40 X. In an inner portion of the main body portion 201, portions
finishes being operated. corresponding to the groove portions 201c are protruding
FIG. 16 is a timing chart showing another example (Case 3) portions that protrude toward the rotation axis X.
in which the aforementioned control operations (3) and (2) A groove provided between the protruding portions serves
are carried out. In this example, see a case where such an as a guiding groove by which toner contained in the main
operation of supplying toner from the toner cartridge 100 to 45 body portion 201 is guided from the rear end portion 2016 to
the toner hopper 110 is carried out for two seconds (control the top end portion 201a. As shown in FIG. 17(a), each of the
operation (3)) at the point of time when the remaining toner groove portions 201c has (i) a lower side which faces in the
amount sensor 116 indicates a detection result "Low". In this direction of gravitational force and which is tilted toward the
case, a counting of the integrated rotation time of the toner top end portion 201a and (ii) an upper side which faces in an
hopper 110 for the purpose of the control operation (2) is not 50 direction opposite to the direction of gravitational force and
carried out while the toner cartridge 100 is being rotated (for which is tilted toward the rear end portion 2016. Thus, when
two seconds). This prevents the toner cartridge 100 from the toner bottle 200 is rotated on the rotation axis X in the
supplying an excessive amount of toner to the toner hopper direction Y, the toner contained in the toner bottle 200 is
110. transported from the rear end portion 2016 of the main body
In FIG. 16, the operation (el) of the toner cartridge 100 is 55 portion 201 to the top end portion 201a of the main body
started due to the control operation (3). In this case, a counting portion 201.
of the integrated rotation time of the toner hopper 110 for the As shown in FIG. 18, the top end portion 201a has a
purpose of the control operation (2) is not carried out. Note cylindrical shape having a diameter smaller than the diameter
that the operations (e2), (e3) and (e4) of the toner cartridge of a central portion of the main body portion 201. The top end
100 correspond to the operations (d3), (d4), and (d5) shown in go portion 201a has a top end surface 201d on which outwardly
FIG. 15, respectively. protruding ribs 202 are provided. The ribs 202 engage with
According to the foregoing control operation, the hopper the cartridge driving motor 150 when the toner cartridge 100
driving motor 151 is rotated in accordance with a toner supply is mounted in the printer A.
request that is based on a result of detection carried out by the Further, as shown in FIG. 19, the top end portion 201a has
toner density sensor 160, and the rotation of the hopper driv- 65 a circumferential surface 201e on which plate scrapers 203
ing motor 151 causes the cartridge driving motor 150 to be are provided, and each of the scrapers 203 is made of elastic
rotated. However, the hopper driving motor 151 and the car- resin such as rubber. The scraper 203 is provided on a surface
 US 7,668,470 B2
15 16
of a ring-shaped fixing member 204 made of stretchable housing 302, the wall portion 301c, and the wall portion 302c.
material (elastic resin such as rubber). In the present embodiment, the first space is referred to as a
As shown in FIG. 20, when the fixing member 204 is toner discharge regulating chamber 300c for regulating dis-
mounted on the top end portion 201a, the two scrapers 203 charge of toner. On the other hand, apart from the first space,
form a substantially straight line extending through the center 5 another space (second space) is formed between the first dam
O of the top end portion 201a. portion 3016 and the second dam portion 3026. The second
Further, as shown in FIG. 20, the main body portion 201 space is referred to as a toner discharging chamber 300d for
has an end face 201g uneven with the top end portion 201a. temporarily storing toner supplied from the toner bottle 200
On the end face 201g, as shown in FIG. 20, a bottle-side toner and then discharging the toner.
outlet 201/z is provided via which the toner contained in the 10 The toner discharge regulating chamber 300c is not a space
main body portion 201 is discharged. into which toner is actually discharged, but functions as a
The toner discharged via the bottle-side toner outlet 201/z is space through which the scraper 203 having passed over the
stored in the bottle supporting member 300 provided so as to first dam portion 3016 is allowed to pass. In the toner dis-
cover the top end portion 201a. The bottle supporting member charge regulating chamber 300c, there exists a small amount
300 is provided with a supporter-side toner outlet via which 15 of toner having passed over the first dam portion 3016
the toner thus stored is discharged. together with the scraper 203. The toner is scraped out
(Bottle Supporting Member 300) through the second dam portion 3026 by a rotational move-
As shown in FIGS. 17(a) and 17(b), the bottle supporting ment of the scraper 203.
member 300 has a substantially cylindrical shape, and On the other hand, the toner discharging chamber 300d
includes first and second housings 301 and 302 joined so as to 20 functions as a space in which toner discharged via the bottle-
cover the top end portion 201a of the main body portion 201. side toner outlet 201/z of the toner bottle 200 is temporarily
The bottle supporting member 300 is provided with a first stored.
opening 300a so that the ribs 202 provided on the top end As shown in FIG. 23, the first dam portion 3016 has a
surface 201d of the top end portion 201a are at least exposed. contact surface 301e that makes contact with the scraper 203.
Provided on a surface of the first housing 301 are first and 25 The contact surface 301e is tilted toward a rotation direction
second fixing members 303 and 304 for fixing the toner of the scraper 203 (i.e., toward the direction of the arrow of
cartridge 100 mounted in the printer A shown in FIG. 2. As FIG. 23) so that the scraper 203 can successfully pass over the
shown in FIG. 17(b), the shutter mechanism 400 is provided first dam portion 3016. That is, the contact surface 301e is
between the first fixing member 303 and the second fixing tilted so as to be displaced, in the rotation direction of the
member 304. The shutter mechanism 400 carries out such a 30 scraper 203, from a normal line L extending from the center
control operation that the toner supplied from the toner car- of rotation O of the toner bottle 200.
tridge 100 is discharged outwardly. In other words, the first dam portion 3016 is provided on an
As shown in FIG. 21, the toner supporting member 300 has upstream side of a direction in which toner is transported by
a supporter-side toner outlet 3006 provided on a bottom sur- the scraper 203, and has the contact surface 301e which
face side of the first housing 301, i.e., between the first fixing 35 makes contact with the scraper 203 and which is tilted by a
member 303 and the second fixing member 304. The sup- predetermined angle (3 from the normal line L extending from
porter-side toner outlet 3006 is opened and closed by the the center of rotation O. In this way, the toner discharging
shutter mechanism 400. chamber 300<ibecomes separate. The angle (3 is appropriately
As shown in FIG. 22(a), the first housing 301 has an inner set depending on the material of the scraper 203, the length of
circumferential surface 301a. Provided near the aforemen- 40 the scraper 203, and other factors.
tioned supporter-side toner outlet 3006 on the inner circum- Further, the first dam portion 3016 is provided in a location
ferential surface 301a are (i) a first dam portion 3016 for that is slightly displaced from the toner outlet 3006 in the
banking up toner and (ii) a wall portion 301c extending from rotation direction of the scraper 203. With this, toner is easily
the first dam portion 3016 in a direction opposite to the accumulated in the toner discharging chamber 300d. By thus
supporter-side toner outlet 3006. The wall portion 301c is 45 making it easy for toner to be accumulated in the toner dis-
provided so as to be separated from a contact surface 301d by charging chamber 300d, it becomes possible to stabilize the
a predetermined distance. The contact surface 301d is an end amount of toner to be supplied via the toner outlet 3006. That
surface of an inner portion of the first housing 301. The is, this makes it possible to stably supply toner.
distance is set to be slightly wider than the width of each of the Furthermore, the length of each of the longer sides of the
scrapers 203. 50 scraper 203 is set to be slightly longer than the distance
As shown in FIG. 22(6), as with the first housing 301 between the center of rotation of the toner bottle 200 and the
shown in FIG. 22(a), the second housing 302 has an inner inner circumferential surface of the bottle supporting member
circumferential surface 302a. Provided on the inner circum- 300, i.e., the inside diameter of the bottle supporting member
ferential surface 302a are (i) a second dam portion 3026 for 300. With this, toner stored in the toner discharging chamber
banking up toner and (ii) a wall portion 302c extending from 55 300d is efficiently scraped out.
the second dam portion 3026. The wall portion 302c is pro- Further, as with the first dam portion 3016, the second dam
vided so as to be separated from a contact surface 302d by a portion 3026 has a contact surface 302e (i.e., surface facing
predetermined distance. The contact surface 302d is an end toward the toner discharge regulating chamber 300c) that
surface of an inner portion of the second housing 302. The makes contact with the scraper 203. The contact surface 3 02e
distance is set to be slightly wider than the width of each of the 60 is tilted by a predetermined angle (3 from the normal line L
scrapers 203. extending from the center of rotation O. In this way, the toner
The bottle supporting member 300 shown in FIG. 21 is discharging chamber 300d becomes separate. The angle (3 is
obtained by combining the first housing 301 with the second appropriately set depending on the material of the scraper
housing 302. As shown in FIG. 23, when the first housing 301 203, the length of the scraper 203, and other factors.
and the second housing 302 are joined, a first space is formed 65 (Explanation of a Sealing Mechanism)
which is surrounded by the first dam portion 3016 of the first In the toner cartridge 100 of the foregoing arrangement, the
housing 301, the second dam portion 3026 of the second toner bottle 200 is rotatably supported by the bottle support-
 US 7,668,470 B2
17 18
ing member 3 00, so that there is a small gap between the toner FIG. 26(b) shows such a state that the toner outlet 3006 of
bottle 200 and the bottle supporting member 300. For this the bottle supporting member 300 is closed by sliding the
reason, unless the gap is appropriately sealed, toner leaks shutter member 401 of the shutter mechanism 400 in the
somewhere other than the toner outlet 3006 of the bottle direction of the arrow F.
supporting member 300. 5 The technology described herein makes it possible to sta-
Therefore, in the present embodiment, as shown in FIG. 24, bly supply a developer at a high speed, and therefore can be
the top end portion 201a of the main body portion 201 of the applied to an image forming apparatus capable of high-speed
toner bottle 200 is provided with two V-shaped rings 501 and printing and high-speed copying.
502 each serving as a seal. A toner supplying device of the technology described
The V-shaped ring 501 is mounted on a circumferential 10 herein includes: a toner density sensor for detecting a toner
surface 201fof the top end portion 201a, and the circumfer- density in a developer tank; a first toner supplying section for
ential surface 201/(FIG. 18) is closer to the ribs 202 than is supplying toner to the developer tank; a second toner supply-
the location in which the scraper 203 is mounted. The ing section for supplying toner to the first toner supplying
V-shaped ring 502 is mounted on the end face 201g of the top section; and a control section, when a request to supply toner
end portion 201a, and the end face 201g is farther from the 15 to the developer tank is made in accordance with a signal
ribs 202 than is the location in which the scraper 203 is detected by the toner density sensor, for controlling the first
mounted. toner supplying section and the second toner supplying sec-
In a location farther from the main body portion 201 than is tion so that (i) the first toner supplying section supplies toner
the location in which the V-shaped ring 501 is mounted, a slip to the developer tank and (ii) the second toner supplying
20 section supplies toner to the first toner supplying section.
ring 503 is mounted. The slip ring 503 ensures the clearance
of the gap existing between the toner bottle 200 and the toner Further, a toner supplying method of the technology
supporting member 300, and is a plate circular member for described herein is a method for supplying toner from a first
allowing the toner bottle 200 to be smoothly rotated. toner supplying section to a developer tank, and for supplying
The V-shaped rings 501 and 502 are mounted on the main toner from a second toner supplying section to the first toner
body portion 201 so that (i) a sealing piece 501a of the 25 supplying section, the method, including the step of: when a
V-shaped ring 501 is pressed against the slip ring 503 and (ii) shortage in toner density in the developer tank is detected, (i)
a sealing piece 502a of the V-shaped ring 502 is pressed causing the first toner supplying section to supply toner to the
against an inner circumferential surface (described later) of developer tank and (ii) causing the second toner supplying
the bottle supporting member 300. This allows each of the section to supply toner to the first toner supplying section.
two V-shaped rings 501 and 502 to function as a seal. 30 According to the foregoing arrangement, the first toner
The slip ring 503 rotatably engages with the circumferen- supplying section supplies toner to the developer tank in cases
tial surface 201fof the top end portion 201a of the main body where a shortage in toner density in the developer tank is
portion 201, and is fixed by the inner circumferential surface detected, and the second toner supplying section supplies
of the bottle supporting member 300 when the bottle support- toner to the first toner supplying section in cases where a
ing member 300 is attached to the toner bottle 200. 35 supply of toner by the first toner supplying section to the
developer tank is detected. Therefore, the supply of toner
Thus, the slip ring 503 is fixed by the bottle supporting
from the second toner supplying section to the first toner
member 300, and the main body portion 201 of the toner
supplying section is not carried out depending on a result of
bottle 200 is rotated on an inner circumferential surface of the
detection carried out by a remaining toner amount sensor
slip ring 503.
40 provided for example in the first toner supplying section, but
As shown in FIG. 25, the V-shaped ring 502 is mounted on is carried out in cases where the first toner supplying section
the top end portion 201a so that when the top end portion supplies toner to the developer tank.
201a of the main body portion 201 of the toner bottle 200 is Thus, even when the first toner supplying section has a
supported by the bottle supporting member 300, the sealing small size and a small capacity, belated supply of toner from
piece 502a is pressed against the inner circumferential sur- the second toner supplying section to the first toner supplying
face 300e of the supporting member 300. This makes it pos- section is prevented, so that there is no shortage in remaining
sible to prevent toner from leaking from a rear end portion toner amount in the first toner supplying section. This makes
SOO/'of the bottle supporting member 300. it possible to stably supply toner from the first toner supplying
Further, as shown in FIG. 25, plate ribs 210 are provided on section to the developer tank.
a circumferential surface of the top end portion 201a of the 50 The toner supplying device may be arranged such that: the
main body portion 201 of the toner bottle 200. The plate ribs control section (a) integrates time during which the first toner
210 are made, for example, of elastic resin. The plate ribs 210 supplying section is supplying toner to the developer tank and
extend in parallel with each other in an oblique direction. (b) causes, every time the time thus integrated reaches a first
(Explanation of the Shutter Mechanism) set time, the second toner supplying section to supply toner to
As shown in FIGS. 26(a) and 26(b), the shutter mechanism 55 the first toner supplying section.
400 includes a shutter member 401 capable of being slid in the According to the foregoing arrangement, by appropriately
direction of the arrow R and in the direction of the arrow F on setting the first set time, it is possible to prevent toner from
the bottom surface of the bottle-supporting member 300. In being accumulated near a toner inlet, via which toner is sup-
FIGS. 26(a) and 26(b), the side toward which the ribs 202 of plied from the second toner supplying section, of the first
the toner bottle 200 protrudes from the opening 300a of the go toner supplying section. That is, it is possible to supply toner
top end portion of the bottle supporting member 300 is from the second toner supplying section to the first toner
referred to as "front (F) side", the side opposite to the F side supplying section in accordance with an amount of toner
is referred to as "rear (R) side". transported in the first toner supplying section.
FIG. 26(a) shows such a state that the toner outlet 3006 of The toner supplying device may be arranged such that: the
the bottle supporting member 300 is opened by sliding the 65 first toner supplying section includes (i) a toner inlet via
shutter member 401 of the shutter mechanism 400 in the which toner is supplied from the second toner supplying
direction of the arrow R. section, (ii) a toner outlet via which the toner to be supplied to
 US 7,668,470 B2
19 20
the first supplying section is discharged, (iii) a toner transpor- The toner supplying device may be arranged so as to fur-
tation path, provided in a direction so as to cross a vertical ther include: a display section for carrying out a display; a
direction, which extends from the toner inlet to the toner display control section for controlling the display section; and
outlet, and (iv) a toner transporting member, provided in the a remaining toner amount detecting section for detecting a
toner transportation path, which sequentially transports toner, 5 remaining toner amount in the first toner supplying section,
dropped onto the toner transportation path via the toner inlet, the second toner supplying section including a toner car-
to cause the toner to drop via the toner outlet. tridge, and when the remaining toner amount detecting sec-
The foregoing arrangement allows the first toner supplying tion has detected for a certain period of time or longer a
section to have a thin and small structure, and therefore allows shortage in remaining toner amount, the display control sec-
miniaturization of the toner supplying device. Further, in the 10 tion controlling the display section to carry out a display
first toner supplying section having the toner transportation suggesting replacement of the toner cartridge.
path provided in the direction so as to cross the vertical The foregoing arrangement allows a user to easily know
direction, it is possible to prevent the toner transportation path when the toner cartridge should be replaced.
from having a toner shortage region free or short of toner. This The embodiments and concrete examples of implementa-
makes it possible to stably supply toner from the first toner 15 tion discussed in the foregoing detailed explanation serve
supplying section to the developer tank. solely to illustrate the technical details of the technology
The toner supplying device may be arranged such that: the described herein, which should not be narrowly interpreted
control section (a) integrates time during which the first toner within the limits of such embodiments and concrete
supplying section is supplying toner to the developer tank and examples, but rather may be applied in many variations
(b) causes, every time the time thus integrated reaches a first 20 within the spirit of the present invention, provided such varia-
set time, the second toner supplying section to supply toner to tions do not exceed the scope of the patent claims set forth
the first toner supplying section; the first toner supplying below.
section includes (i) a toner inlet via which toner is supplied What is claimed is:
from the second toner supplying section, (ii) a toner outlet via 1. A toner supplying device, comprising:
which the toner to be supplied to the first supplying section is 25 a toner density sensor for detecting a toner density in a
discharged, (iii) a toner transportation path, provided in a developer tank;
direction so as to cross a vertical direction, which extends first toner supplying means for supplying toner to the
from the toner inlet to the toner outlet, and (iv) a toner trans- developer tank;
porting member, provided in the toner transportation path, second toner supplying means for supplying toner to the
which sequentially transports toner, dropped onto the toner 30 first toner supplying means; and
transportation path through the toner inlet, to cause the toner control means, when a request to supply toner to the devel-
to drop via the toner outlet; and the first set time is set in oper tank is made in accordance with a signal detected
accordance with time required for the toner transporting by the toner density sensor, for controlling the first toner
member to transport toner outward a region, which is located supplying means and the second toner supplying means
directly below the toner inlet, in the toner transportation path 35 so that (i) the first toner supplying means supplies toner
of the first toner supplying section. to the developer tank and (ii) the second toner supplying
The foregoing arrangement allows the first toner supplying means supplies toner to the first toner supplying means.
section to have a thin and small structure, and therefore allows 2. The toner supplying device as set forth in claim 1,
miniaturization of the toner supplying device. Further, in the wherein the first toner supplying means includes (i) a toner
first toner supplying section having the toner transportation 40 inlet via which toner is supplied from the second toner sup-
path provided in the direction so as to cross the vertical plying means, (ii) a toner outlet via which the toner to be
direction, it is possible to prevent the toner transportation path supplied to the first toner supplying means is discharged, (iii)
from having a toner shortage region free or short of toner. This a toner transportation path, provided in a direction so as to
makes it possible to stably supply toner from the first toner cross a vertical direction, which extends from the toner inlet
supplying section to the developer tank. 45 to the toner outlet, and (iv) a toner transporting member,
The toner supplying device may be arranged such that: the provided in the toner transportation path, which sequentially
second toner supplying section includes a toner bottle, con- transports toner, dropped onto the toner transportation path
taining toner therein, which is rotated to discharge the toner. via the toner inlet, to cause the toner to drop via the toner
According to the foregoing arrangement, the second toner outlet.
supplying section includes the toner bottle, containing the 50 3. The toner supplying device as set forth in claim 2,
toner therein, which is rotated to discharge the toner. This wherein the toner transporting member is a toner transporting
makes it easy to control an amount of toner to be supplied. screw which is rotated to stir and transport the toner.
Thus, even in cases where the first toner supplying section is 4. The toner supplying device as set forth in claim 1, further
miniaturized, the second toner supplying section is always comprising:
able to stably supply toner to the first toner supplying section. 55 display means for carrying out a display;
The toner supplying device may be arranged so as to fur- display control means for controlling the display means;
ther include a supplying pipe, extending in an up-and-down and
direction, which has (i) one end connected to the toner outlet remaining toner amount detecting means for detecting a
of the first toner supplying section and (ii) another end con- remaining toner amount in the first toner supplying
nected to the developer tank. 60 means,
According to the foregoing arrangement, even in cases the second toner supplying means including a toner car-
where such a toner supplying device that toner is supplied tridge, and
from the first toner supplying section to the developer tank via when the remaining toner amount detecting means has
the supplying pipe extending in an up-and-down direction is detected for a certain period of time or longer a shortage
disposed in a limited space, it is possible to stably supply an 65 in remaining toner amount, the display control means
appropriate amount of toner from the first toner supplying controlling the display means to carry out a display
section to the supplying pipe. suggesting replacement of the toner cartridge.
 US 7,668,470 B2
21 22
5. A developing device, comprising a toner supplying means, (ii) a toner outlet via which the toner to be sup-
device as set forth in claim 1. plied to the first toner supplying means is discharged,
6. An image forming apparatus, comprising a developing (iii) a toner transportation path, provided in a direction
device as set forth in claim 5. so as to cross a vertical direction, which extends from the
7. A toner supplying device, comprising: 5 toner inlet to the toner outlet, and (iv) a toner transport-
a toner density sensor for detecting a toner density in a ing member, provided in the toner transportation path,
developer tank; which sequentially transports toner, dropped onto the
first toner supplying means for supplying toner to the toner transportation path via the toner inlet, to cause the
developer tank; toner to drop via the toner outlet; and
second toner supplying means for supplying toner to the 10 the first set time is set in accordance with time required for
first toner supplying means; and the toner transporting member to transport toner out-
control means for controlling the first toner supplying ward a region, which is located directly below the toner
means and the second toner supplying means so that (i) inlet, in the toner transportation path of the first toner
the first toner supplying means supplies toner to the supplying means.
developer tank when a request to supply toner to the 15 13. The toner supplying device as set forth in claim 7,
developer tank is made in accordance with a signal further comprising:
detected by the toner density sensor and (ii) the second display means for carrying out a display;
toner supplying means supplies toner to the first toner display control means for controlling the display means;
supplying means when a supply of toner by the first toner and
supplying means to the developer tank is detected. 20 remaining toner amount detecting means for detecting a
8. The toner supplying device as set forth in claim 7, remaining toner amount in the first toner supplying
wherein the control means (a) integrates time during which means,
the first toner supplying means is supplying toner to the the second toner supplying means including a toner car-
developer tank and (b) causes, every time the time thus inte- tridge, and
grated reaches a first set time, the second toner supplying 25 when the remaining toner amount detecting means has
means to supply toner to the first toner supplying means. detected for a certain period of time or longer a shortage
9. The toner supplying device as set forth in claim 7, in remaining toner amount, the display control means
wherein the first toner supplying means includes (i) a toner controlling the display means to carry out a display
inlet via which toner is supplied from the second toner sup- suggesting replacement of the toner cartridge.
plying means, (ii) a toner outlet via which the toner to be 30 14. A developing device, comprising a toner supplying
supplied to the first toner supplying means is discharged, (iii) device as set forth in claim 7.
a toner transportation path, provided in a direction so as to 15. An image forming apparatus, comprising a developing
cross a vertical direction, which extends from the toner inlet device as set forth in claim 14.
to the toner outlet, and (iv) a toner transporting member, 16. A method for supplying toner from first toner supplying
provided in the toner transportation path, which sequentially 35 means to a developer tank, and for supplying toner from
transports toner, dropped onto the toner transportation path second toner supplying means to the first toner supplying
via the toner inlet, to cause the toner to drop via the toner means,
outlet. the method, comprising the step of:
10. The toner supplying device as set forth in claim 9, when a shortage in toner density in the developer tank is
wherein the second toner supplying means includes a toner 40 detected, (i) causing the first toner supplying means to
bottle, containing toner therein, which is rotated to discharge supply toner to the developer tank and (ii) causing the
the toner. second toner supplying means to supply toner to the first
11. The toner supplying device as set forth in claim 9, toner supplying means.
further comprising: 17. A method for supplying toner from first toner supplying
a supplying pipe, extending in an up-and-down direction, 45 means to a developer tank, and for supplying toner from
which has (i) one end connected to the toner outlet of the second toner supplying means to the first toner supplying
first toner supplying means and (ii) another end con- means,
nected to the developer tank. the method, comprising the steps of:
12. The toner supplying device as set forth in claim 7, when a shortage in toner density in the developer tank is
wherein: 50 detected, causing the first toner supplying means to sup-
the control means (a) integrates time during which the first ply toner to the developer tank; and
toner supplying means is supplying toner to the devel- when a supply of toner by the first toner supplying means
oper tank and (b) causes, every time the time thus inte- to the developer tank is detected, causing the second
grated reaches a first set time, the second toner supplying toner supplying means to supply toner to the first
meansto supply toner to the first toner supplying means; 55 toner supplying means.
the first toner supplying means includes (i) a toner inlet via
which toner is supplied from the second toner supplying